Popular Electronics® WORLD'S LARGEST SELLING ELECTRONICS MAGAZINE JULY 1977 / $1.

25

"Zap" New Life Into

Dead NiCd Batteries
Two Fantastic
AUDIO
Video Projects
Tape Recorder Hygiene
HOW TO MAINTAIN RECORDERS tttttt:tt:tttt::t::tttt:::tt::
IN PEAK CONDITION :

i BUILD THIS TUT -6 i

Build a Low-Cost i
t
YOUR SOFTWARE CONTROL CAN
INCLUDE INTERLACE. SCROLLING,
Pink Noise Generator *

i
L A FULL PERFORMANCE CURSOR

UP 4096 =HARP
TO CHARACTERS
E

A VALUABLE AUDIO TEST TOOL t ON THE SCREEN IN LESS THAN =

t THREE MEGAHERTZ TV BANOWIOTH
COMMUNICATIONS t t
Ttt:ttttttttttttttttttttttttt)
Deciphering Utility
BUILD DON LANCASTER'S
Code Broadcasts
LATEST !!TV TYPEWRITER"
Without Knowing It's a $35 Interface Board
Morse Code!
TEST REPORTS

Radio Shack STA -2000 :

.

7.; Tod::
Stereo FM /AM Receiver COSMRC
Koss K-145 Stereo Headphones
Cobra 29XLR 40- Channel AM
G= ELF
r

CB Mobile Transceiver
E84G47 H0
N1 1:: :&11.891
LO
31N3 Ntl: COMES TO THE
07
o
641nn 0141 46046910 3 :3 tOCOMPUTER!
210409

14024 14278
i
I pis one's Less Than $25
Poular Electronics
 Introducing the mobile that can move And like all Cobras it comes equipped
you out of the world of the ordinary with such standard features as an easy -
and into the world of the serious CB er. to -read LED channel indicator.
The Cobra 138XLR Single Sideband. Switchable noise blanking and limiting.
Sidebanding puts An RF /signal strength meter. And
you in your own Cobra's exclusive DynaMike gain control.
private world. A You'll find the 138XLR SSB wherever
world where there's Cobras are sold. Which is almost every-
less congestion. where. Because Cobra's got a nationwide
More privacy. network of dealers and Authorized
More time to talk. Service Centers offering sales, installation,
It's all possible because instead of 40 service and advice. So come on in.
channels you get your choice of 120 And move on up.

c bra
channels. Both AM and SSB. And
instead of 4 watts of legal power you
aet 12 watts of legal power. So you get
almost double the range of AM.
With the 138XLR Single Sideband Punches through loud and clear.
there's less background noise and less Cobra Communications Products
interference. So there's cleaner, clearer DYNASCAN CORPORATION
reception. Because like all Cobras, the 6460 W Cortland St., Chicago, Illinois 60635
Write for color brochure
138XLR SSB is engineered to punch EXPORTERS: Empire Pènview, N Y CANADA: Atlas Electronics Toronto

through loud and clear. Even in crowded CIRCLE No. 9 ON FREE INFORMATION CARD

metropolitan areas.

UPWARD
 Photo courtesy of Edmund Scientific Co.

AVANTI Invents the Saturn Base

The reason the "Saturn" is so revolutionary Those of you who are worried about sun
is that it is absolutely the only combination spots and "skip" can relax too. This antenna
vertical and horizontal omni -directional really helps. When the sun spots cause a
antenna. That's right, it needs no rotor! signal shift, you can often change polarity
You can pick up mobiles (which are vertical) (just like our P.D.L. or Moonraker) and still
or horizontal and vertical beams. pick up the desired channel with no loss of
The "Saturn ", invented after years of re- transmission.
search by Avanti engineers, is the latest The P.D.L. and Moonraker made dual polarity
development using AVANTI's unique CO- famous as the only antennas to have during
INDUCTIVE principle to give you the per- the last sun spot cycle, and this time around
formance of two antennas combined into Height 22' any serious C.B.'er will want to have the
Radials 9'
one. Weight 11 lbs.
"Saturn."
The "Saturn" not only works on both Omni -directional -
No rotor In fact, having a "Saturn" and a "P.D.L."
polarities, but pounds out signals like an AV -501 Switchbox Included or "Moonraker" will put you in the elite
air hammer and picks them up like a magnet. group of C.B.'ers who "always seem to get
Both polarities offer high gain figures. out better."
Avanti makes a complete line of high performance base and mobile
CB antennas from $11.95 to $404.00. Write for free Avanti catalog.

AVANTI RESEARCH AND DEVELOPMENT, INC.,

340 Stewart Avenue, Addison, IL 60101
Copyright 1977, All rights reserved Creators of the famous
CIRCLE NO 6 ON FREE INFORMATION CARD
 IT'S WHAT YOC GET WHEN YOU RUN WITH NUMBER 1. MIDLAND CB.

WE GOT 7'd THE TOP ON PURE GUTS.

C.oisistency. If one word can perform every watt and ohm as -fight out of the box.
5L:m up Midland's rise to reliably as the first Midland off Add to that Midland's 15
`lumber 1 in CB, that's it. the line. years' experience in CB,
We've got to know that the To make sure, we use Midland's warranty and
:ei- thousandth Midland wil computer technology through- :onvenient authorized service
out the manufacture of all our :enters, coast to coast.
new 40- channel models. Pure guts. Pure reliability.
In the assembly and . ure Midland Power. That's
"RUN integration of our state- of -the- what yot. get when you run
WITH art circuitry. with Number 1.
In the ultra -fine tuning of For your free, full -color,
those circuits. 24 -page 1977 Midland CB
And in the final testing of arochure, write: Midland
0J./.4+e-42i your new 40- channel Midland nternational, P.O. Box 12737,
CB, so you know it'll deliver, `forth Kansas City, Mo. 64116

A member cf the Beneficial Corporation family.

C
Shop fa these activà living products from Midland international: 3eichnark Tools
Goodwin Sportir g Goods Moda IicnCar--Sound Products Midland Tèiev SPX- Young World Toys.
`ORCIE NO_ -28 ON FREE _INFORMATION CARO
 JULY 1977 VOLUME 12, NUMBER 1

Popular Electronics® WORLDS LARGEST- SELLING ELECTRONICS MAGAZINE

FEATURE ARTICLES
RC CIRCUIT QUIZ Robert P. Balin 26
NOISE FILTERING FOR HI -FI Julian D. Hirsch 32
PIXIE ANIMATION PROGRAM Edward C. Deveaux 42
END THAT "UTILITY FUTILITY" Harry L. Helms, Jr. 53
DX'ing CW without knowing Morse code.
TAPE RECORDER HYGIENE Craig Stark 56
The importance of taking care of your machine and tapes.
AN INTRODUCTION TO GYRATOR THEORY Bryan T. Morrison 58
"ZAP" NEW LIFE INTO DEAD NiCd BATTERIES Douglas C. Myers 60
THE WORLD OF ELECTRONICS Frank Bolle 67
AVERAGE, PEAK, AND RMS VALUES Hector French 68
HOBBYIST COMPUTER CLUBS 91

CONSTRUCTION ARTICLES
COSMAC ELF, PART IV Joseph A. Weisbecker 41
One added chip provides video interface and animated graphics.
ELECTRONIC "BELL" FOR A TVT -II Denis J. Deutsch 46
BUILD THE TVT-6: A LOW -COST DIRECT VIDEO DISPLAY Don Lancaster 47
User-selectable line lengths; scrolling; and up to 4k on- screen characters.
BUILD A PINK NOISE GENERATOR FOR AUDIO TESTING Dennis Bohn 66
BUILD A SOLAR CONTROLLER Jerald M. Cogswell 69
PORTABLE 60-HZ "CLOCK" OSCILLATOR Charles F. Smith 70
ONE -TOUCH DIODE TESTER David Markegard 75
COLUMNS
STEREO SCENE Ralph Hodges 22
Instruments I Have Miked.
SOLID STATE Lou Garner 77
IC's For Test Instruments.
EXPERIMENTER'S CORNER Forrest M. Mims 82
The 556 Timer.
HOBBY SCENE John McVeigh 84
CB SCENE Ray Newhall 88
The Anatomy of CBRS.
COMPUTER BITS Hal Chamberlin 89
Assemblers.

JULIAN HIRSCH AUDIO REPORTS

REALISTIC MODEL STA -2000 STEREO RECEIVER 33
KOSS MODEL K/145 STEREO HEADPHONES 36
ELECTRONIC PRODUCT TEST REPORTS
COBRA MODEL 29 XLR MOBILE 40-CHANNEL CB TRANSCEIVER 85
WAHL MODELS 7700 AND 7800 CORDLESS SOLDERING IRONS 86

DEPARTMENTS
EDITORIAL ArtSalsberg 4
Solar Energy News Notes.
LETTERS 6
OUT OF TUNE 7
"Bicycle Speedometer" (March 1977); "LED Racing Game" (March 1977); "Digistart Lock" (April 1977).
NEW PRODUCTS 12
NEW LITERATURE 16
NEWS HIGHLIGHTS 38
TIPS & TECHNIQUES 92
OPERATION ASSIST 93
ELECTRONICS LIBRARY 95
POPULAR ELECTRONICS, July 1977, Volume 12, Number 1, Published Material in this publication may not be reproduced in any form without per-
monthly at One Park Avenue, New York, NY 10016. One year subscription rate mission. Requests for permission should be directed to Jerry Schneider, Rights
for U.S. and Possessions, $12.00; Canada, $15.00; all other countries, $17.00 and Permissions, Ziff-Davis Publishing Co., One Park Ave., New York, NY
(cash orders only, payable in U.S. currency). Second Class postage paid at 10016.
New York, NY and at additional mailing offices. Authorized as second class
mail by the Post Office Department, Ottawa, Canada, and for payment of post- Editorial correspondence: POPULAR ELECTRONICS, 1 Park Ave., New
age in cash. York, NY 10016. Editorial contributions must be accompanied by return post-
POPULAR ELECTRONICS including ELECTRONICS WORLD, Trade Mark age and will be handled with reasonable care; however, publisher assumes no
Registered. Indexed in the Reader's Guide to Periodical Literature. responsibility for return or safety of manuscripts, art work, or models.
COPYRIGHT 1977 BY ZIFF -DAVIS PUBLISHING COMPANY. ALL Forms 3579 and all subscription correspondence: POPULAR ELEC-
RIGHTS RESERVED. TRONICS, Circulation Dept., P.O. Box 2774, Boulder, CO 80302. Please allow
Ziff-Davis also publishes Boating, Car and Driver, Cycle, Flying, Modem at least eight weeks for change of address. Include your old address, enclos-
Bride, Popular Photography, Skiing and Stereo Review. ing, if possible, an address label from a recent issue.

JULY 1977 3
Popular Electronics®
EDGAR W. HOPPER
Publisher

ARTHUR P.SALSBERG
Editorial Director
LESLIE SOLOMON
Technical Editor

JOHN R. RIGGS
`
Managing Editor

IVAN BERGER
Senior Editor

ALEXANDER W. BURAWA
Features Editor

EDWARD I. BUXBAUM
Art Director

JOHN McVEIGH
Associate Editor

ANDRE DUZANT
Technical Illustrator

PATRICIA GIRRIER-BROWN
Production Editor

Contributing Editors
HAL CHAMBERLIN, LOU GARNER
GLENN HAUSER, JULIAN HIRSCH
RALPH HODGES, FORREST MIMS
RAY NEWHALL, WILFRED SCHERER

JOSEPH E. HALLORAN
Advertising Director

JOHN J. CORTON
Advertising Sales

LINDA BLUM
Advertising Service Manager

PEGIMcENEANEY
Executive Assistant

STANLEY NEUFELD
Associate Publisher

ZIFF -DAVIS PUBLISHING COMPANY

Popular Electronics
Editorial and Executive Offices
One Park Avenue New York, New York 10016
212 -725 -3500
Hershel B. Sarbin, President
Furman Hebb, Executive Vice President
John R. Emery, Sr Vice President, Finance and Treasurer
Phillip T Heffernan, Sr. Vice President
Edward D. Muhlfeld, Sr. Vice President, Sports Division
Philip Sine, Sr. Vice President
Frank Pomerantz, Vice President, Creative Services
Arthur W. Butzow, Vice President, Production
Lawrence Sporn, Vice President, Circulation
George Morrissey, Vice President
Sydney H. Rogers, Vice President
Sidney Holtz, Vice President
Albert S. Traira, Vice President
Philip Korsant, Vice President
Paul H. Chook, Vice President
Edgar W. Hopper, Vice President
Charles B. Seton, Secretary
William Ziff, Chairman
W. Bradford Briggs, Vice Chairman

Midwestern Office
The Paths Group, 4761 West Touhy Ave.,
Lincolnwood, Illinois 60646, 312 679 -1100
Thomas Hockney, Michael Neri, Gerald E. Wolfe
Western Office
9025 Wilshire Boulevard, Beverly Hills, CA 90211
213- 273 -8050; BRadshaw 2 -1161
Western Advertising Manager Bud Dean
Japan. James Yagi
Oji Palace Aoyama; 6-25, Minami Aoyama
6 Choose, Minato-Ku, Tokyo 407 -1930/6821,
582 -2851
áYJ
OA

r T
sti w co'
¡r _
" a
Member Audit Bureau
of Circulations
The publisher has no knowledge of any proprietary rights
which will be violated by the making or using of any items dis
closed in this issue
4
 Do-it-yourself JBL.
Take the guts of
what makes JBLJBL
and adapt it to your
own ideas of what a
loudspeaker system
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Mix and match with
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See your authorized
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team in sound: You
and JBL.

JULY 1977 5
 large quantities, at least in the midwest, by article is incorrect for my 1973 Lafayette Ra-
ether extraction from the saliva of pregnant dio Model HA -600A receiver. The correct tie
sows, this seemed like the logical starting point is the junction of C31 and R16. The cir-
point. Reduction of this ketone with sodium cuit board in the receiver is already drilled to
borohydride gave the alcohol that, upon treat- permit such a connection. -Stephen E.
ment with propionyl chloride in pyridine, gave Franklin, Ellicott City, MD
the desired propionate ester in good yield.
The solar cell was then constructed pretty

Letters
I built the "Digital Frequency Readout"
much as described, except that a glass spray project from a kit supplied by Mattis Electron-
bottle could not be used to apply the com- ics and am delighted with it. was impressed
I

pound to the sand. This is because the chem- by the fine kit of parts supplied. Everything
ical also reacts with the silica in the glass and was included aid the project worked immedi-
the resulting deoxygenation process is vio- ately upon completion. -D.C. Mead, Greens-
lent. A plastic bottle, however, works quite boro, NC
DOCTORS SAY NOT TO WORRY
well. The cell actually is more efficient than
No matter how "spacey" the rest of the the one described, providing about 87% con-
world got, could always depend on good ole
I version. -Dr. C. T. C.Creedy and co- workers, AN ERROR IN SWITCHING
PE to be swimming in the "real" world of Charles F. Kettering Research Laboratory, In "Build a Digital Bicycle Speedometer"
parts specifications and product news. Then I Yellow Springs, OH. (March 1977), t is stated that, to calibrate the
saw April's "How to DX Earth Radio From project one mist "depress S2 and adjust R2
Outer Space." still talk to myself and my
I
until the display indicates the wheel's diame-
hands shake, but the doctors tell me not to You stated that car-radio frequency drift
ter." Since S2 is the power switch, the in-
worry. Just kidding. can't begin to tell you
how much
I

enjoy reading your magazine.

was due to the Doppler effect and that the
problem should be corrected with a phase-
structions should read: "depress S3 ..."-
I
Rick Stievenarr, Carbon, IN.
-Michael Swaney, Erie, PA. locked loop. My God, tell the fool to slow
down! For an audible Doppler shift to occur in
ETC HAS ROM MONITOR
the commercial AM band (let's say 5 Hz, to
be conservative), this person would have to THANKS FOR THE "ELF"
Iread with interest the April 1977 Comput- be driving faster than 5000 mph. By helping My thanks to Joe Weisbecker for designing
er Bits column and was not pleased that the him to keep his radio tuned, you are aiding the "COSMAC Elf Microcomputer" (August
only remark about our product was an unfa- and abetting this reckless and unlawful oper- 1976). built my micro using slide switches,
I

vorable comparison with a competitor, espe- ation of a motor vehicle.- Walter Satre, discrete LED's, and a 555 timer IC for econo-
cially when this remark was based on misin- Chairman, Electrical & Electronics Technolo- my. (In my project, the 555 timer can be
formation. The Model ETC -1000 Basic Sys- gy Dept., Vermont Technical College, Ran- placed in either of two positions in a 16 -pin
tem includes a 40 -key keyboard that is oper- dolph Center, VT. DIP socket to give me either a high or a low
ated by a monitor system that permits the clock.)
user to effectively operate a minimum system In discussing the well -known effect of ra-
The basic construction technique used inI

or to initialize and perform other housekeep- diation pressure from car stereo speakers in assembling my Elf was Wire Wrap, with two
ing operations in systems with terminal inter- the April Hobby Scene, Marcia Swampfelder bus strips for power distribution. My main
faces. Our terminal monitor version comes in overlooked the most important application of problem during assembly was trying to find
two packages, the 8k and 16k configuration them all: swinging the speakers forward to 22 -pin Wire Wrap sockets. Since couldn't
I

(the latter including an assembler), and dis- assist in braking. Such dynamic air braking find them anywhere, had to build my own
I

assembler, Basic, cassette /O, Utilities, and

I
does not wear down the tires and has been from Molex Scldercons, Vector J pins, and
a variety of other program packages. -E.S. used effectively for years in fire engines. epoxy cement. My next project is to build my
Bjornsson, Electronic Tool Co., Hawthorne, When close to the fire, the driver swings his Elf with a hex keyboard and 1024 words of
CA. siren around to hasten the stop. You can de- memory. -Charles J. 8illwiller, Rancho Cor-
termine the precise moment when he does dova, CA.
Our apologies for the erroneous descrip- this from the change in pitch, caused by the
tion of the ETC -1000. The ROM monitor sys- Doppler effect, provided you are not close to
tem indeed uses 40 buttons to allow calling the fire. -Harry E. Stockman, Arlington, MA.
routines from the monitor without need of a SLIDE SYNCER STEERS MOTORBOAT
terminal. Debugging is simplified by using a I enjoyed buirding "The 35 -mm Slide Sync -

buht-in break -point routine, and included is a DX'ING EARTH ON CHANNEL 68 er" (November 1976). Found the circuit to be
thorough memory diagnostic system. so stable that I plan to use two of them in a
The statement that there is only one chan-
programmable steering system for my motor-
"DIGISTART'S" COLLAPSING FIELD nel 68 in North America in "How to DX Earth
boat. The only "bug" in the system is that it
Radio From Outer Space" (April 1977) is in-
After reading the "Digistart" (April 1977) will trigger from some momentary signals oth-
correct. Independent station WBTB TV in Ne-
article, noticed a minor omission in the cir- er than its center -frequency signal. This prob-
I
wark, NJ operates on channel 68. -John J.
cuit that might cause operating problems. lem can be eliminated by increasing the value
Dynarski, Carteret, NJ
When the 01 transistor cuts off, the collaps- of C6 to 20 or 30 p.F.
ing field of the K1 coil could induce a large I also found that the circuit refused to trig-

enough back emf to destroy the transistor. To FREQUENCY READOUT PROJECT A HIT ger at low signal levels. I discovered that by
remedy this, it is suggested that a diode be paralleling R2 with a 50,000 -ohm potentiom-
I wish to thank POPULAR ELECTRONICS and
installed across the relay's coil in reverse eter, this second problem could be elimi-
author David L. Mattis for the "Digital Fre-
bias. To be on the safe side, the rectifier di- nated. These modifications ensure excellent
quency Readout for Shortwave Receivers"
ode should be rated at no less than 100 PIV circuit operation. -Mark Irgang, New York,
(February 1977). After connecting it to my re-
at 1 ampere. -Alan Bradford, Derry, NH. ceiver, it was surprisingly accurate and sta-
NY.

ble. can set my receiver to a predetermined

I

"APRIL FOOL" IS 2 -WAY STREET frequency and just wait for the signal to fade
We were intrigued with the high- efficiency in. Also, the display is especially bright and MORE SOLAR VIEWING SAFETY
solar cell described in the April Hobby Scene. clear and can be read from clear across the "Propagation Forecasts For Radio Corn -
Because the corresponding ketone (3,7- room. munications" (November 1976) contains an
dimethylpentadecan -2 -one) is available in Incidentally, the hookup point given in the error regarding the use of the Kodak #4 neu-
6 POPULAR ELECTRONICS
tral- density filter which could have serious shift" amplifier. The class -K amp is similar to IC12 as shown here, the two unused 7411
consequences. The safest way to view the the class -A amp except that the average di- gates can be used to block the clock pulse
sun through binoculars or a telescope is by rect current to the power amplifier is con-
projection. If direct viewing is required, it trolled as a function of the audio level. Thus, ALL LEO'S
should be done only through full- aperture fil- no more power is consumed than is neces- A 530
ters of the deposited -metal -film type such as
SC/2- 390 n +SV
sary to minimize distortion for a particular au- 75'4'1 2
that shown on the telescope in Fig. 3 of the dio level. This makes its average efficiency
article. These filters effectively block all harm-
ful radiation.
Another method is to use one or more lay-
ers of black and white (not color) film that has
been exposed to direct sunlight and then de-
appreciably higher than for the class -A am-
plifier. The principal virtue of the class -K am-
plifier is that it yields about twice the power
output of a class -A system, using the same
tube or transistor. Of course, the class -K sys-
_CC //,
SC/0, P/N 2
+
PiN z
/ 2

SC SC
-

/5
*ADD 70
4.7K#
-MME
EACH STAGE

veloped. These are suitable for direct viewing

but not photography because they degrade
tem is not suitable for hi -fi without special re-
finements because of difficulties in handling SC9,
G/5'2
2
the image. transients. But it performs well in voice ap-
Another area of danger is in the use of the plications, such as in modulating communica-
so- called "sun filters" supplied with many tion equipment. -Dala Hileman, WB6NTR, /3
2
inexpensive telescopes. These filters are Topanga, CA
meant to be used on the eyepiece. Since they SC4C
will be near the focal plane of the main objec-
tive lens or mirror, it is possible that sufficient CLOCK PUL. 5E /2
TO 2CZ
heat could be built up in the filter to cause it to
crack. The damage to the eye would occur
before the observer could move away from
the eyepiece. -John Hudak, Vice President,
Out of Tune P/NS /, í; 9 /2

when any one of the four players reaches the

finish first. This will eliminate any doubt as to
Hamilton Centre of the Royal Astronomical the winner if all four players wish to race at
Society of Canada, Ontario, Canada. In "Bicycle Speedometer" (March 1977), the same time.
the segment -f pin of 1C2 in Fig. 1 was incor-
In the "Digistart Lock" (April 1977), contact
rectly identified as pin 16; it should be pin 10.
bounce problems in flip -flop A can be re-
ANOTHER CLASS OF AMPLIFIER In "LED Racing Game" (March 1977), pins duced by connecting pin 1 (J) to +5V and pin
We read with interest "Classes of Audio 7 and 8 of IC13 in Fig. 4 are reversed. Also, 4 (K) to gnd. On IC5, the Q output is pin 1. For
Amplifiers" (March 1977) and noted that al- pir 16 of 106, IC7, and 1C8 must be connect- more stability in the one -shot multivibrator,
though the article covered classes A through ed to the +5 -volt bus (see Fig. 6). If you add a change R6 to 39,000 ohms (1/4 -watt) and Cl
G, it failed to mention the class K "reference 4700-ohm, '/4 -watt resistor to 1C9 through to 120 µF.

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Our connectors are industry standard;
two parallel rows of contacts, spaced
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Great Jumpers come in five popular cable
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(216) 354 -2101 TWX: 810- 425 -2250

CIRCLE NO 1 ON FREE INFORMATION CARD

JULY 1977 7
 Learn to service Communications /CB
equipment at home...with
NRI'S COMPLETE
COMMUNICATIONS COURSE
Learn design, installation and maintenance of
commercial, amateur, or CB communications
equipment.
The field of communications is bursting out all
over. In Citizens Band alone, class D licenses
grew from 1 to over 2.6 million in 1975, and the
FCC projects about 15 million CB'ers in the U.S.
by 1979. That means a lot of service and
maintenance jobs .. and NRI can train you at
.

home to fill one of those openings. NRI's

Complete Communications Course covers all
types of two -way
radio equipment
(including CB),
AM and FM

special instruction so you can go on the air.

The complete course includes 48 lessons, 9
special reference texts, and 10 training kits.
Included are: your own electronics Discovery Lab,
Antenna Applications Lab, CMOS Frequency
Counter, and an Optical Transmission System.
You'll learn at home, progressing at your own
speed, to your FCC license and into the
communications field of your choice.
Transmission and Reception,
Television Broadcasting,
Microwave Systems, NEW CB SPECIALIST
Radar Principles,
Marine Electronics, COURSE NOW OFFERED
Mobile Communica-
tions, and Aircraft Electronics.
The course will also qualify you for
a First Class Radio Telephone Commercial FCC
License or you get your tuition back.
Learn on your own 400 -channel digitally-
synthesized VHF transceiver.
NRI now offers a special course in CB Servicing.
You will learn to service all types of communi-
You get 37 lessons. 8 reference texts, your own
cation equipment, with the one unit that is CB Transceiver, AC power supply and multi -
designed mechanically and electronically to train meter ...for hands -on training. Also included
you for CB, Commercial and Amateur communi are 14 coaching units to make it easy to get
cations: a digitally- synthesized 400 -channel VHF your commercial radio telephone FCC license -
transceiver and AC power supply. This 2 -meter enabling you to test, install, and service com-
unit gives you "Power -On" training. Then we munications equipment.
help you get your FCC Amateur License with
8 POPULAR ELECTRONICS
 NRI offers you five TV/Audio
Servicing Courses
NRI can train you at home to service TV
equipment and audio systems. You can
choose from 5
courses, starting
with a 48- lesson
basic course, up
to a Master Color
TV /Audio Course,
complete with
designed -for-
learning 25" diago-
nal solid state color TV and a 4- speaker SQ''
Quadraphonic Audio System. NRI gives you
both TV and Audio servicing for hundreds of
dollars less than the two courses as offered by
another home study school.
All courses are available with low down payment
and convenient monthly payments. All courses
provide professional tools and "Power -On"
equipment along with NRI kits engineered for
training. With the Master Course, for instance, you
build your own 5" wide -band triggered sweep solid
state oscilloscope, digital color TV pattern
generator, CMOS digital frequency counter, and
NRI electronics Discovery Lab. "Trademark of CBS Inc.

NRI's complete computer electronics course

gives you real digital training.
Digital electronics is the career area of the future ...
and the
best way to learn is with NRI's Complete Computer Elec-
tronics Course. NRI's programmable digital computer goes
far beyond any "logic trainer" in preparing you to
become a computer or digital technician. With the IC's
in its new Memory Kit, you get the only home training
in machine language programming ... experience
essential to trouble shooting digital computers. And
the NRI programmable computer is just one of ten
kits you receive, including a TVOM and NRI's
exclusive electronics lab. It's the quickest and best
way to learn digital logic and computer operation.
You pay less for NRI training and you get more
for your money.
NRI employs no salesmen, pays no commissions. salesman will call. Do it today and get started on
We pass the savings on to you in reduced tuitions that new career.
and extras in the way of professional equipment,
testing instruments, etc. You can pay more, but APPROVED UNDER GI BILI.
if taken for career purposes Check box ori card fer details.
you can't get better training.
More than one million students have enrolled
with NRI in 62 years. NßINRI SCHOOLS
r4 McGraw -Hill Continuing Education Center
Mail the insert card and discover for yourself why C, 3939 Wisconsin Avenue,
NRI is the recognized leader in home training. No
JULY 1977
'I 1 Washington, D.C. 20016
lati
11
 tional wiring required. The Solar Hot Rod is MOTOROLA CB RADIO CARRYING CASE
said to provide 14 dB of signal gain to the re-
A Universal Carrying Case for mobile CB
ceiver with less than 2 dB of noise gain. The
transceivers nas been introduced by the Mo-
Solar Power Supply is claimed to be able to
torola Communications Group Parts Dept.
maintain a fully charged supply, enough to
The case permits easy removal of a CB radio
provide several months operation in total
so it can be carried by the owner from an
darkness. $89.95.
CIRCLE NO. 91 ON FREE INFORMATION CARD
unattended vehicle. Separate compartments

New Products
Additional information on new products AMCOMM 2 -METER FM TRANSCEIVER
covered in this section is available from
the manufacturers. Either circle the item's The Model S225 2 -meter mobile FM trans-
code number on the Reader Service Card ceiver from AMCOMM (American Communi-
inside the back cover or write to the man- cations Corp.) features a digital synthesizer
ufacturer at the address given. that provides complete coverage of the 2-
meter ham band in 5 -kHz increments. Oper-
ating frequency is determined by three rotary
in the case hold microphones, the power ca-
ble, and a pertable antenna. The case is de-
DYNACO INTEGRATED AMPLIFIER signed so a mobile radio can be operated
The Model SCA-50 integrated amplifier is without removing it from the case. Openings
available from Dynaco /Dynakit either factory at the top and bottom of the case allow the
assembled or in kit form. It is rated at 25 speakers to be heard, while a large opening
watts /channel continuous average power at the back permits antenna and power con-
with less than 0.5% THD with 8 -ohm loads. nections. The front flap folds down so that the
The bass and treble control circuits are de- transceiver controls and microphone jack are
readily accessible. Covered with Texion vinyl
that simulates genuine leather and equipped
switches and is displayed to the nearest ki- with a heavy -duty handle, the case measures
lohertz on a six -digit LED display. Transmit 12" x 9" x 3" (30.5 x 23 x 7.6 cm).
offsets are switch selectable for +600 kHz, CIRCLE NO 94 ON FREE INFORMATION CARO

-600 kHz, +1 MHz and -1 MHz. R -f output

power is continuously variable from 2 to 25
watts, with spurious harmonic output at -60
SENCORE AUDIO -VHF FREQUENCY COUNTER
dB. Receiver sensitivity is rated at 0.5 i.V for
20 dB quieting. Local oscillator frequency sta- Sencore's F -45 frequency counter offers
signed to have little or no effect on the mid- bility is claimed to be ±5 ppm. Audio output continuous frequency check capability from
range. The turnover in the bass control sys- power is rated at 4 watts into the built -in 8- audio through vhf (uhf -band coverage to 600
tem is variable, while that in the treble system ohm speaker with less than 10% distortion. MHz with optional PR47 prescaler). A direct -
is fixed and has a hinge frequency that is The transmitter is phase modulated ( ±5 kHz reading eight -digit dispaly with pushbutton
h gher than is usual. In the amplifier section, with 100% modulation at 1000 Hz), and T/R
the output circuit is full complementary switching is solid state. A Touch -Tone encod-
symmetry, and the bias supply thermally er is optional.
tracks the output transistors. A thump -sup- CIRCLE NO. 92 ON FREE INFORMATION CARD

pression circuit (for turn -on /turn -off) is stand-

ard. In addition to the line fuse, protection in-
cludes separate fuses at each of the four
OPTONICA FRONT -LOAD CASSETTE DECK
power supply outputs, current limiting, and a
thermal circuit breaker. $149 kit; $249 factory Sharp Electronic Corp.'s Optonica Model
wired. RT -2050U is a two- motor, front -loaded cas-
CIRCLE NO. 89 ON FREE INFORMATION CARD sette deck. Wow and flutter is rated at
0.045% weighted rms, and S/N ratio is 64 dB action makes the FC45 easy to use. Incorpo-
with its Dolby noise- reduction system rates a crystal checker. Counter sensitivity is
RAYMALEE CB MOBILE ANTENNA switched in. An automatic program find sys- 25 mV average throughout the band; accura-
cy is 1 ppm, using a temperature -controlled
The Solar Hot Rod, from Raymalee, is a pow-
oven. The basic unit comes with all testing
er -gain CB antenna featuring a self -con-
leads at $395. The PR47 prescaler is $125.
tained solar -powered device with built -in so-
CIRCLE NO 95 ON FREE INFORMATION CARO
lar storage. It clamps to the user's present
mobile or base -station antenna with no addi-

NAKAMICHI FM TUNER /PREAMPLIFIER

tem (APFS) enables the user to move to the
next selection or to return to the start of the The Model 630 FM tuner /preamplifier from
current selection simply by pushing a button. Nakamichi is said to provide an extremely
Among other features are: a space setter, low-noise, low- distortion preamplifier section.
peak level meters (respond to signals in 10 Noise is ratec at 80 dB below 1 mV, and dis-
ms), electronic automatic stop, and three - tortion is claimed to be virtually impossible to
position BIAS and EQUALIZER tape selection measure. A phono overload of 250 mV and a
switches, pause switch, counter, stereo switch -selectable phono input sensitivity en-
headphone jack, separate record level con- sure compatibility with a wide variety of car-
trols, and a ganged output control. $299.95. tridges. The preamp section also provides
CIRCLE NO. 93 ON FREE INFORMATION CARD tone and contour controls, tape deck monitor
12 POPULAR ELECTRONICS
 32K. One Card. One low price.
Only from the Digital Group.
Now, on only one fully static card, the Digital Group has All data and address lines are buffered
squeezed in a whopping 32K of memory. Which, with a little Fully static memories -EMM 4801 (450ns) or equiva-
quick addition, means a full 64K architecture now requires lent
only 2 boards instead of 8. That's a 4-to -1 space reduction Price:
...and leaves one extra memory slot on the Digital Group's 32K board complete, assembled and tested $995.00
standard motherboard still available for future products.
For all the memorable details, just fill out the coupon below.
All this and one low price, too.
(Then all you have to remember is to mail it in.)
It just may be the best news of all. Our full static, assembled
and tested 32K memory board is only $995. Now that's worth
remembering. It's substantially less than our equivalent as-
sembled 8K board prices. (Please note: We're initially offer-
ing this 32K board assembled only, but kit versions will soon CMG UngimP
be available, too -at
even lower prices.) P.O. Box 6528
Here's what you get. Denver, Colorado 80206 (303) 777-7133
Specifications: I promise to mail this in, so add me to your mailing list!
32K on single card
Speed- 450ns. All of our current CPUs will operate at Name
full -rated speed.

-
Decoding-Lower or upper 32K bank
Power +5V only C 4A
Card size -12" x 5" (excluding connector fingers)
Address

Features: City /State /Zip

May be intermixed on Digital Group systems with our Remember me? I'm already on your mailing list, but I need the
8K memory cards memory spec sheet desperately.
CIRCLE NO. 12 ON FREE INFORMATION CARD
JULY 1977 13
 RS232 current loop, and five relays. The con-
trol computer incorporates the Intel
8048/8748 microcomputer chip, which will
accommodate three separate and unique
memory stages: program memory, internal
register memory, and external RAM. Input a
program through the onboard keyboard, at-
tach the device, and immediate control of the stead of the 10 dual op amps used in the ear-
lier model to obtain better slew rates and han-
dling of transients. Additionally, the new op
amps are claimed to allow a greater range on
and copy facilities, and a high output head-
the level control. One quad op amp operates
phone amplifier. The FM tuner section fea-
as an isolation amplifer to eliminate imped-
tures low -noise dual -gate MOSFETs, a six - ance mismatching problems. Continuously
element LC network, and a switch -selectable variable filters two per channel, can be used
wide /narrow -band response. FM sensitivity
to perform ether crossover or bandpass
is 13.75 dBf (1.5 µV for 30 dB quieting), and a
capture ratio of 1 dB. Incorporates a Dolby 0als 0000
000 0000
s ,

functions. Eacn filter in the dual -channel sys-

tem is variable from 20 to 20,000 Hz with a
nose- reduction unit with 25 -µs deemphasis.
$600.00. 0000 0000 fixed rolloff of 18 dB /octave. Output imped-
ance is 300 ohms in both inverted and nonin-
CIRCLE NO. 96 ON FREE INFORMATION CARD
verted modes, with greater than 6 volts max-
imum into 600 ohms. IM distortion and noise
devices is said to be obtained. Both kit and are rated at 0.31% and more than 100 dB be-
IMSAI SINGLE -BOARD COMPUTER assembled versions are available: ROM ver- low the rated output with 0 dB of gain, respec-
sion ($249, kit; $299, assembled), EROM tively. $329 for VFX -2A, $49.95 for optional
IMSAI's new 8048 control computer is a com-
version ($399, kit; $499, assembled). A 5 -V walnut- veneer cabinet.
pletely programmable computer and hard-
power supply is $99. CIRCLE NO. 98 ON FREE INFORMATION CARD
ware control system on one 81/2" x 10" board.
CIRCLE NO. 97 ON FREE INFORMATION CARD
It is powered by a 5 -V supply or 6-V battery
and allows standard electric tools, instru-
TRIPLETT PORTABLE DMM
ments, and appliances to be attached and
CROWN ELECTRONIC CROSSOVER
controlled directly without requiring any inter- A single switch provides five functions and 22
vening hardware other than wire. The 8048 8- The Crown Model VFX-2A is the successor to measurement ranges on the compact bat-
bit CPU contains 1k words of program memo- the Model VFX-2 electronic crossover. Inter- tery- powered Model 3000 digital multimeter
ry, and the system has cassette interface, nally, the VFX -2A uses six quad op amps in- from Triplett. The 31/2-digit display features

Aircommand 40-channel cg. From the people who bring 4 big Watts of RF power. Aircommand delivers the maxi-
you Marantz -the world's mum power legally allowable to let you belt out the big sound.
finest stereo systems - 100% modulation capability. Even when you talk softly
comes the Aircommand into the mike, your message cuts through loud and clear,
CB- 640 -the finest in thanks to one of the most advanced mike preamp and
40- channe. CB. With compressor designs in CB today. With Aircommand, you
Aircommand you get don't have to spend an extra $30 to $40 on a "power mike"
over 25 years experi- You can't buy better modulation than Aircommand.
ence in outstanding Specially tailored frequency response.
2 -way communications LED 40- channel selection display. Easy -to -read, night or day.
products. 8 -LED (light emitting diode) meter display. Provides
Full 6 Watts of audio an easy-to -read display of SWR (standing wave ratio),
power. Provides plenty
of punch so your speaker
modulation, and incoming or outgoing signal strength -
instantly, accurately.
cuts through freeway noise. Special emergency Channel 9 scan with exclusive
Dual- conversion super- Aircommand "beep" alert. No matter what channel you're
heterodyne receiver with on, a special Aircommand CB-640 circuit continuously
dual- cascaded ceramic and silently monitors Emergency Channel 9. When some-
filters.Together, Doth fea- one starts transmitting on Channel 9, a unique "beep"
tures provide the most com- alerts you, so you can tune yourself in and give assistance.
plete rejection of unwanted
Public address capability. The versatile Aircommand
signals, assuring you unsur-
CB-640 public address package lets you (1.) Talk into the
passed selectivity and
CB mike and out an exterior public address speaker.
sensitivity.
(2.) Attach a tape recorder to the auxiliary jack on the

14 POPULAR ELECTRONICS
 quency response of 20- 25,000 Hz ±2 dB and matic feed of preset amounts of solder. It ac-
an adapter containing a power supply and cepts various diameters and brands of solder
matching transformers. Other specs include: wire, interchangeable elements and tips
less than 0.3% THD at 100 dB SPL, 50 watts (20- 30 -40 -60-watt elements available), and
at 1 kHz maximum input, and 118 dB SPL has optional accessories for practically any
maximum output. The low -mass conductive type of soldering work. The standard kit is
diaphragms are made of an extremely light $49.50 with interchangeable heating ele-
material called "Polyurethin." The power sup- ments $13 each; soldering tips, $7.30; solder
ply is housed in a walnut enclosure, which is reels $2.25 and $5.95 depending on size. Ad-
connected between the amplifier and speak- dress: Minitool, 15076 Dickens Ave., San
ers. Front -panel switching allows head- Jose, CA 95124.

seven -segment LED's with blinking over -

range, auto- zeroing, and autopolarity indica- ROYAL MOBILE AMPLIFIER

tion. All decimal points light up when the bat- Royal Sound has a new mobile stereo high-
tery is low. Ranges include: 0 to 0.2, 2, 20, fidelity power amplifier module, the RS -55,
200, and 600 on both ac and dc volts; 0 to 2, that's normally driven by speaker output
20, and 200 mA on ac and dc; 0 to 200, 20k, leads of an FM /AM radio with cassette play-
and 2M ohms on low-power ohms; and 0 to er. The module increases amplifier output for
2k, 200k, and 20M ohms on conventional car audio equipment by providing a power
ohms. Typical ratings include 0.9% dc ac- output of 15 watts/channel. Self- contained,
curacy, 10- megohm input resistance on all the RS-55 is ruggedly constructed to with-
voltage ranges, and 600-volt overload protec- stand shock and vibration. It also has sepa-
tion on all ranges. The DMM is powered by
four Ni -Cd cells, for which a battery- charger/ phones to remain connected whether they or
eliminator is provided. Size is 53/4" x 3" x the speaker systems are being used. The
1W (13.7 x 7.6 X 3.5 cm) and weight is 10 headset weighs 9 ounces. The complete sys-
oz (310 g). $140. tem is $275.
CIRCLE NO. 99 ON FREE INFORMATION CARD CIRCLE NO. 100 ON FREE INFORMATION CARD
rate bass and treble controls, on /off switch,
power indicator light, and quick-connect ter-
ONE -HAND SOLDERING
minals, and can be mounted anywhere in a
INFINITY ELECTROSTATIC HEADPHONES
The Kager KL-3000 is Minitool's answer to car or van. Operates on 12 -volt dc negative-
Infinity System's ES -1 headphone system the problem of one -hand soldering on elec- g round only. $90.00
consists of headphones with a claimed fre- tronic circuits. The gun has adjustable, auto- CIRCLE NO. 101 ON FREE INFORMATION CARD

,.You never heard it so good!!!

CB -640 rear panel, and boom your tape out through the automatic noise limiting switch, noise blanking switch,
same external speaker. (3.) Mix your voice from the squelch control, RF gain control.
CB microphone with the program material on the tape
recorder. Both voice and tape sound at the same time Also available: Aircommand CB-140; Aircommand
through the external speaker. (4.) Beam your received CB -340. All 3 units bring you state-of -art design, flawless
signal through the external speaker. craftsmanship and day -in, day -out reliability. Try them out
now at your Superscope Aircommand dealer.
Built -in standing wave ratio circuitry. Measures the effi-
ciency of the antenna system for optimum performance.
Other outstanding features include: Delta fine tuning TM
SUPERSCOPE.
control, digital synthesizer with phase-locked loop, by

©1977 Superscope, Inc., 20525 Nordhoff St., Chatsworth, CA 91311. Prices and models subject to change without notice.

JULY 1977 15
 or TV, test instruments, digital clocks, radio wall radio; a storm alarm which is triggered by
control equipment and auto accessories. a signal from a local National Weather Serv-
Among the new products introduced are a a- ice station; anc a Sol -20 computer with Basic
way bookshelf speaker system, a battery 5language. Address: Edmund Scientific Co.,
monitor device for radio control modelers, a 555 Edscorp Bldg., Barrington, NJ 08007.
two -way freezer alarm and a touch -control
light switch. A section of fully assembled
WINEGARD CB ANTENNA CATALOG
bra-id-name 40- channel CB radios has also

New Literature been included. Address: Heath Co., Dept

350 -11, Benton Harbor, MI 49022.
Winegard Industries offers its first CB Anten-
na Catalog #770. The catalog illustrates the
company's line of 40- channel CB mobile an-
tennas and accessories, providing technical
EDMUND CATALOG information and specifications. A listing of
HEATHKIT CATALOG Edmund Scientific's 164-page Spring Cata- available antenna replacement parts is also
The new 96 -page Heathkit Catalog describes log #772 contains over 4500 items for experi- included. Address: Winegard Industries, Inc.,
over 400 electronic kits. Product categories menters, students and hobbyists. Among the 3002A Winegard Dr., Burlington, IA 52601.
Inc ude amateur radio, hi -fi components, col- many iterrs described are an AM /FM deluxe
MOTOROLA HEP CATALOG

ARE YOU READY The new, 184-page edition of the HEP Semi-
conductor Cross Reference Guide and Cata-
TO RECEIVE THE WORLD? log is offered by Motorola. Includes replace-
ment HEP semiconductors for over 60,000
ALL NEW discrete devices and IC's, with 198 new prod-
fully synthesized DR22 Receiver ucts. Covers discrete silicon and germanium
power transistors, thyristors, small -signal
general coverage receiver FET's and bipolar transistors, zeners, digital
from McKAY DYMEK $995. IC's, voltage regulator and op amps. The
Educator II microcomputer power supply kits
are also included. Address: HEP/MRO Oper-
ations HeadgJarters, Motorola Products,
Inc., PO Box 20902, Phoenix, AZ 85036.

ADWAR VIDEO EDITING GUIDE

Adwar Video's 9 -page guide offers advice on

editing with hal- -inch tape and video cassette
equipment. It begins with basic tips on avoid-
ing quality losses and editorial confusion, and
goes on to deal with scene edits; search and
review; insert editing; and quality- enhancing
modifications to VTR's. New video process-
FEATURES
ing and portable field editing are also high-
Shortwave. CB, ham racio. ships at Eu,l: in power supply for 110 -120 or lighted. Address: Adwar Video Corp., 100 5th
sea, overseas phone calls. etc. 220-240 VAC switchable, 50-60 Hz. Ave., New York, NY 10011.
Hi Fi. SWL. commercial, industrial Solid state, phase locked, digital
and government ases. s¡irthesis tuning.
High level RF front end for excellent inter - SYNC TAPE RECORDERS 8 PLAYERS
Extreme ease of tuning at all
modulation resection and sensitivity. freq _encies. A 4 -page brochure from Audiotronics de-
Crystal filters in first and second IF No mechanical tuning dial error or scribes its line of SYNC Classette tape re-
amplifiers, ceramic filter in third IF. back lash. corders and players. The units, designed as
Quartz crystal tuning accuracy at all Sw tch selectable 4 or 8 kHz RF aids for synchronized presentations of re-
frequencies, no crystals to buy. bandwidth. corded audio tape to slide /filmstrip projec-
Built in monitor speaker with external tors, include Model 144S, which plays both
speaker connectors. superimposed and separate track synchro-
SPECIFICATIONS
nized cassette :apes. Another, Model 152 -2,
Frequency coverage: 50 kHz to 29.7 MHz, continuous. Digital synthesis in 5 kHz steps, features an automatic stop program. The bro-
fine tune fors5 kHz. chure illustrates each device and describes
Reception modes: AM, upper sideband, lower sidebend, CW. the different sync functions. A specification
Sensitivity for 100 kHz 200 kHz 300 kHz -20MHz 20-29.7 MHz chart allows for easy comparison of models.
10dB S + N /N: CW,SSB 10 try 2.DpV 0.5µV '.0/rV Address: Audiotronics Corp., 7428 Bellaire
AM 30äV 6.0µV 1.0 MV 2.0//V
Ave., N. Hollywood, CA 91605.
RF Bandwidth: -3dB @ 4 kHz or e kHz, and -60d6 @ 10 kHz or 14 kHz
Dimensions & Wt.: (W x D x H) 17.5 x 14.5 x 5.1 inches. Shpg. Wt. 19 lbs.
SPERRY MULTI -TESTER BROCHURE

DR22 features and specifications unmatched under $2900. Bulletin SP -73 ;Issue B) from a.w. Sperry de-
scribes its line of V- O -Ma -T multi- testers. The
Order factory direct. call 7 -page pocket -sized brochure provides de-
toll free today. Exclusive In Canada tailed specifications, applications information,
McKay Dymek Co. rent /own plan available. Great Metropoli:an and a list of special features for each tester.
Natioiwide Sound Co. Ltd. Accessories a-e also described. Address:
'675 N. Park Ave.
800/854 -7769 12C Eglinton Avenue East
Box 2100
P.O.
Pomona CA 91766
® Califonia
800/472 -1783
Toron:o.Ca'ada M4P i
Tel.416/484 -0800
E2 a.w. Sperry Instruments, Inc., 245 Marcus
Blvd., Hauppauge, NY 11787.
CIRCLE NO 27 ON FREE INFERMA -101i CARO
16 POPULAR ELECTRONICS
We've just made the impossible...
a professional 31/2 digit DMM Kit for less than $60.

1O0mv IOV 1NV

1OyA 1mA 1OOmA
POWER AC VOIE AMP OHM I (1 10N 1OOf1 .10

1111 1111
The Sabtronics Model 2000 is an impossible $59.95!
And that price still includes phenomenal accuracy, range
and professional features.
This all -new bench /portable multimeter, reading to
±1999, has a basic accuracy of 0.1% ± 1 digit, and has
five functions giving 28 ranges, 100% overrange and
overload protection. So you know it's no toy!
Besides, what toys are as automatic as the 2000? With
automatic over range indication, automatic polarity,
even automatic zeroing!
Yet the 2000 is easy to assemble. We send you all the
parts you need, even the high- impact case. We also send
you clear, step -by -step assembly instructions.
So you end up with a professional quality 31/2 digit
DMM for the unheard -of price of less than $60. From
Sabtronics, specialists in digital technology. And
manufacturers of the impossible.
Order yours today!

sabtronics
Made in U.S.A.

INTERNATIONAL INC.
INC.
P.O. Box 64683 Dallas, Texas 75206 (214) 369-7310

GUARANTEE:
r
Our guarantee to you; examine the 2000
To: Sabtronics International, Inc. PE7
DMM kit for 10 days. If you're not satisfied, P.O. Box 64683, Dallas, TX 75206
return it unassembled for a full refund of
Please send me Sabtronics Model 2000 DMM kit(s) at
purchase price.
$59.95 each. subtotal
SPECIFICATIONS: (condensed)
Shipping and Handling, $3.50 per unit* subtotal
DC volts in 5 ranges: 100µV to 1000V.
Texas Residents Add Sales Tax
AC volts in 5 ranges: 100µV to 1000V.
DC current in 6 ranges: 10nA to 2A. TOTAL enclosed
AC current in 6 ranges: 10nA to 2A. Name
Resistance in 6 ranges: 1S2 to 20MS2
Input Impedance: 10MS1
Street Address
Display: 9mm (.36 ") LED.
Power requirements: 4.5 VDC to 6.5 VDC
City
(4 "C" cells -not included).
Size: 8 "W x 6.5 "D x 3.0 "H. State Zip
(203W x 165D x 76H mm).
'USA only. Canada, $4.50. All Other Countries, $9.00

CIRCLE NO. 45 ON FREE INFORMATION CARD

 Go alter
the best
ofesrerythin¢.

Don't settle for less. Especially when it comes to

electronics training . , , because everything else in your life
may depend on it. That's why you ought to pick CIE:

18 POPULAR ELECTRONICS
 Pick the pace that's right More than half of CIE's courses
you've probably seen ad- prepare you to pass the government-
vertisements from other
electronics schools. Maybe you
for you. administered exam. In continuing
CIE understands people need surveys, nearly 4 out of 5 CIE gradu-
think they're all the same. to learn at their own pace. There's no ates who take the exam get their
They're not! pressure to keep up ... no slow Licenses!
CIE is the largest indepen-
dent home study school in the learners hold you back. If you're a
beginner, you start with the basics.
For professionals only.
world that specializes exclu- Ifyou already know some elec- CIE training is not for the hobby-
sively in electronics. tronics, you move ahead to your ist. It's for people who are willing to
own level. roll up their sleeves and go to work
.to build a career. The work can be
Meet the Electronics Enjoy the promptness of hard, sure. But the benefits are
Specialists. CIE's "same day" grading worth it.
When you pick an electronics cycle. Send for more details
school, you're getting ready to invest When we receive your lesson and a FREE school
some time and money. And your before noon Monday through Satur- catalog.
whole future depends on the educa-
tion you get in return.
day, we grade it and mail it back
the same day. You find out quickly
- Mail the card today. If it's gone,
That's why it makes so much how well you're doing!
cut out and mail the coupon. You'll
sense to go with number one ... with get a FREE school catalog plus com-
the specialists ... with CIE! CIE can prepare you for plete information on independent
home study. For your convenience,
There's no such thing as your FCC License. we'll try to have a CIE representa-
For some electronics jobs, you tive contact you to answer any ques-
bargain education. must have your FCC License. For tions you may have.
If you talked with some of our others, employers often consider it a Mail the card or the coupon or
graduates, chances are you'd find a mark in your favor. Either way, it's write CIE (mentioning name and
lot of them shopped around for their government-certified proof of your date of this magazine) at: 1776 East
training. Not for the lowest priced specific knowledge and skills! 17th Street, Cleveland, Ohio 44114.
but for the best. They pretty much
knew what was available when they
picked CIE as number one.
We don't promise you the moon.
We do promise you a proven way to
build valuable career skills. The CIE
faculty and staff are dedicated to
that. When you graduate, your di-
ploma shows employers you know
what you're about. Today, it's pretty
hard to put a price on that.
Because we're special-
ists, we have to stay
ahead.
At CIE, we've got a position of
leadership to maintain. Here are
some of the ways we hang onto it . .

Our step -by-step learning

includes "hands -on"
training.
At CIE, we believe theory is
important. And our famous
Auto-Programmed® Lessons teach
you the principles in logical steps.
But professionals need more Patterns shown on TV and oscilloscope screens are simulated.
than theory. That's why some of our
courses train you to use tools of the
trade like a 5 MHz triggered- sweep,
solid -state oscilloscope you build
yourself- and use to practice trouble-
shooting. Ora beauty of a 19-inch
diagonal Zenith solid -state color TV
CIE Cleveland Institute of Electronics, Inc.
1776 East 17th Street, Cleveland, Ohio 44114
Accredited Member National Home Study Council
you use to perform actual service
operations.
-
...
YES I want the best of everything! Send me my FREE CIE school
catalog including details about troubleshooting courses -plus my FREE package
Our specialists offer you of home study information.
personal attention. Print Name
Sometimes, you may even have
a question about a specific lesson. Address Apt.
Fine. Write it down and mail it in.
Our experts will answer you City
promptly in writing. You may even State Zip
get the specialized knowledge of all
the CIE specialists. And the answer
you get becomes a part of your per-
manent reference file. You may find
, Age
Check box for G. I. Bill information:
Phone (area code )
Veteran Active Duty

this even better than having a class- 1 MAIL TODAY:

room teacher.
JULY 1977 21
 Tympani (kettledrums) present no
comparable problems, although they
have a well -known tendency to shake
the stage loor and any microphone
stands on it which may cause vibration
pickup. Sometimes a failure to get the

Stereo Scene sound you want from a kettledrum is at-

tributable to the way in which it's played.
Striking the drum in the exact center of
its head produces a rather ridiculous,
overdamped "boomp." As the mallet
By Ralph Hodges
progresses out toward the edge, the
drum acquires that characteristic bale-
ful, almost metallic timbre. A light roll at
INSTRUMENTS I HAVE MIKED the very edge produces almost a rustle.
Tympani are played either with sponge
(or perhaps a spongy synthetic) or felt
mallets; the sonic results from each are
LL BE honest and admit haven't ac-
I Drums and Such. The bass drum, quite different. Felt mallets are exceed-
tually made recordings of all the in- surprisingly, is evidently a highly direc- ingly rare ncwadays, however. Some re-
struments to be mentioned here. Some - tional instrument. Ifirst learned this cordists apparently fear that it's impossi-
tirnes have assisted others while they
I when happened on an unguarded bass
I ble to properly balance the tympani with
recorded them, or fulfilled the function of drum in a rehearsal room at the New the rest of the orchestra unless they are
interested observer and general nui- Englanc Conservatory of Music. Ecstat- recorded w th a separate mike(s) and
sance at a session. And in many cases, ic, hefted the heavy lead- loaded mallet,
I mixed in later. It's not.
my experience with any given instru- poised t well to the side of the drum Professional recordists take elaborate
ment is hardly what you'd call exhaus- head, swung from the hips and shoul- pains with a drum set (kick drum, tom -
tive. I have only recorded a large or- ders, and . . nothing! After a while
. I tom, snare, and one or more cymbals),
chestra once, for example. (I found it realized that the drum heads, apparently festooning it with microphones and stuff-
rather easy; beginner's luck, no doubt.) moving in tandem, were giving rise to an ing towels in the kick drum. They all do it
Every once in a while pick up a piece
I almost perfect acoustic cancellation somewhat differently, so there are no
of data about a particular instrument or around the periphery of the drum, and I general rules, except perhaps in the
recording situation that seems directly was therefore standing in a huge node. case of the cymbal. High -hat cymbals
pertinent to the logistical problem of Not so an innocent passerby outside, move considerably when they are
placing microphones. Sometimes this who met the enormous pressure wave played. If two differently placed micro-
datum immediately suggests a solution as it swept up the corridor. phones happen to be picking up the
tc a miking situation; other times, after From time to time I've encountered cymbal, and you intend to mix the out-
further examination, it proves totally ir- audible evidence of this cancellation puts of these two mikes, you can wind
relevant. In either case, the information node at considerable distances from the up with a very weird Doppler effect that
is good to have. drum itself. So if you're ever puzzled as you may like, but which won't sound nat-
The few really useful general guide- to why your mike is missing the near - ural. (A two -mike pickup exaggerates
lines for placing microphones -the vari- infrasonic throb you expect from a bass the effect.) The best approach with a
oJs ways to achieve a good stereo pick- drum, try turning the drum so that ore drum set is often a simple stereo pickup,
up, the maintaining of acoustic separa- head fapes the mike directly. Converse- balanced by ear.
tion between mikes when you're multi - ly, if you're getting too much throb, turn
tracking, etc. -are ably covered in the the drum so that you get a more edge -cn The Strings. A celebrated concert vi-
several good books on studio technique perspective. olinist has said that a violin doesn't be-
now available. The indispensable rules
o' mike placement -pulling the mikes
back to increase the contribution of
room reverberation, avoiding the close -
u use of cardioid mikes because of var-
ic us frequency- response errors it can in-
trDduce, and so on-are surely well
known to anyone who has taken the
slightest interest in live recording. How-
ever, approaching a specific instrument,
o' assemblage of specific instruments,
gives almost everyone pause, I think.
How do you begin? What's the first
logical move? Having a definite ap-
proach, whether it is vital to the proper
capturing of the sound or not, is confi-
dence- building for all of us, and that's Fig. 1. Phase differences between direct and reflected
hat mean to focus on here.
I signals present a problem when miking a string bass or cello.
22 POPULAR ELECTRONICS
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JULY 1977 23
 bly strong, and they should have a cer- plifiers and the built -in preamps of con-
tain fragility, even thinness, of tone. denser mikes as well as tape, is to get
Where possible, give them a chance to away and cff -axis. Discourage brass
balance naturally with the rest of the or- players from pointing their instruments
chestra. And don't ride gain on them to directly at the microphone or put the
..r..,. any excess. mike where they can't conveniently aim
The string bass, when miked from any at it. Even then, a French horn, which
distance, encounters problems from re- projects rearward in line with the play-
Fig. 2. Trumpet waveform nuked on
axis in anechoie chamber. From a flecting surfaces. Figure 1 shows how er's elbow, and which often has his fist
Denon record made with pulse - the first reflection from the floor bounces stuck up into its bell, can cause trouble.
code- modulation process. up to the microphone, causing a com- Distance is your only recourse then, and
plex pattern of reinforcements and can- here it usually sounds good.
gin to sound good until you're at least cellations, all wavelength- dependent. A
ten feet distant, so that the "garbage" solid wall behind the instrument will pro- Piano. Don t we wish we could make
has had a chance to fall away. Good duce much the same thing. When you're consistently good piano recordings. The
miking advice too rarely taken. At their miking several basses, as in an orches- trouble is, the instrument is too big to
loudest, massed violins are never very tra, the most productive approach is close -mike with one microphone, and
loud compared with the real heavy- usually to ignore these complications when we try -o mix the output of several
weights in a symphony orchestra. In and press on regardless, hoping the ran- microphones there is inevitable trouble
their upper registers, however, they domness factor will solve your problems with interference. Other complications
have a penetrating tone that will often for you. For a single bass, as in a jazz intrude as well.
rise above the most astounding ruckus. combo, it's a frequent practice to mike Presently, for grand piano, favor the
I

If one balances too much in favor of the the instrument quite closely, which will stereo pickup shown in Figure 3. Note
violins (a fault of many commercial re- tend to get rid of the room and, hence, that the two mikes (cardioids or omnidi-
cordings), the aforementioned penetrat- the reflections. Electric basses are al- rectionals, or a coincident pair embrac-
ing tone will give the feeling of going most invariably miked closely (at the ing a moderate angle) are aimed down
right in to your eardrums. amplifier's speaker), or even fed directly into the piano's case approximately in
For a natural- sounding recording, re- into the recorder, bypassing the amp. line with the instrument's lid. This theo-
straint in the handling of violins is admi- retically avoids reflections from the lid
rable. They should not always be audi- Woodwinds. It may be obvious, but
the proper place to mike a woodwind is
not at the bell of the instrument where
you'd expect most of the sound to
emerge. In general, the right place for
COMING UP IN the mike is directly in front of the musi-
THE AUGUST cian, as if he were going to speak into it.
Usually he will play so that the bell is
pointing toward the floor (or, in the case
Popular Electronics` of the bassoon, toward the ceiling). This
is fine. Move the mike(s) closer or far-
BUILD THE "CABONGA" ther away as appropriate, but don't try to
ELECTRONIC DRUMS get too close.
SYNTHESIZER Fig. 3. This mike positioning for
The Brass. The trouble with the brass piano avoids pickup of direct
MEASURE CAMERA SHUTTER is eloquently demonstrated by Figure 2, reflections from bottom of lid.
a drawing of an oscilloscope trace made
SPEED DIGITALLY
by a trumpet in full cry. The vicious spiki- (which I believe to be detrimental to clar-
ness of this waveform will never be.re- ity) from reaching the mikes directly. The
HOW TO PROTECT vealed by any VU meter, and yet it has mikes are brought forward or pulled
MOS DEVICES to be taken into account because any back as necessary to provide that right
DURING INSTALLATION AND significant tampering with this crest will touch of room reverberation.
SOLDERING be audible. In jazz clubs you'll often see There are many other ways of record-
a trumpet played directly into a micro- ing a piano that I'm itching to try as soon
BUILD THE TVT-6: A LOW -COST phone. Apparently, the sound- reinforce- as get the chance. Some of these are
I

DIRECT VIDEO ment system can usually take this on- described in a Shure Brothers' publica-
DISPLAY -PART 2 slaught in stride. But it's murder on tape. tion, "The Music -Maker's Manual of Mi-
I tried to record this trumpet waveform crophone Mastery." Although intended
with a good cassette machine. Finally, for sound reinforcement at live perfor-
TEST REPORTS I

had to drop the recording level down to mances, you can extrapolate its advice
Heath AR -1515 Digital- Readout
the point where the meters (peak read- into a recording situation with relative
Stereo FM /AM Receiver ing) were barely stirring, and still the ease. It's free. (Shure Brothers, 222
Thorens TD -126C Turntable waveform peaks were appreciably ab- Hartrey Ave., Evanston, IL 60204.)
President "Washington" breviated.
40-Channel CB Base Station Your defense against the brass, which The Sound Field. All of us are in-
can easily overload microphone pream- trigued by the examples of recording
24 POPULAR ELECTRONICS
 professionals and hope to emulate their iar with the sound of live music you'll ap- might fracture a glass cup if you heated
results in time. Here's a piece of advice preciate that it sounds, in many re- it when it contained cold water.
offered by several recording profession- spects, better. Above all, have a good (2) Wet playing allows an interface layer
als I have talked to: Forget it! A profes- time, and fulfill yourself while inching to- of liquid to extract tiny amounts of sur-
sional recording session costs multi -dol- ward capturing the full realism of the mu- face stabilizer into a slurry. When this
lars with every tick of the clock. There is sic. Even if the final goal cannot be whol- slurry is allowed to dry back onto the
scarcely time for aesthetic considera- ly reached, you'd be surprised at how surface, there is a concomitant lack of
tions or lengthy consideration of micro- forgiving the human ear is. stabilizers in the right place plus little
phone respositioning. Ideally, a profes- globules in the wrong places.
sional recordist would like to capture ev- More on Decontaminating Discs. (3) Wet playing literally shorts out some
ery instrument in complete isolation and Dr. Bruce Maier, president of Discwash- cartridges by wicking up the cantilever
later mix all the instruments together er, has favored us with some comments and causing the generator assemblies of
(along with appropriate reverberation) at on the recent "Decontamination Squad" some cartridges to corrode very quickly.
his leisure. Hence he turns to the multi - column (May 1977) that I'd like to share. Dr. Maier disagrees with my sugges-
miking approach, which by- and -large He observes that "It has been our ex- tion that record- cleaning substances
sacrifices all the good things -depth,
spaciousness, authentic perspective
of a simple stereo pickup. If you don't
- perience that once you begin wet -play-
ing a record you can never, never play
the record dry again. After two wet
and lubricants can be evaluated by
treating just 180 degrees of a record
side and then listening for any difference
believe me, read John Woram's book, plays, playing the record dry will blow between the two halves. He points out
The Recording Studio Handbook (Saga - you out of the room with surface noise. (quite rightly, suspect) that the transi-
I

more Publishing Co., 1120 Old Country "The reason is fairly complex," says tion points between the halves will al-
Road, Plainview, N.Y.) for some frank Dr. Maier, offering some research con- ways be audible. Had my description
discussion of the subject. clusions concerning wet playing of been more complete, it would have been
If you're an amateur recordist, and discs: clear that the evaluator should listen for
time is not pressing, you have the luxury (1) Wet playing causes an intense dise- any differences between the two halves
of being able to attempt a miking of the quilibrium in temperatures between the other than the noise occurring at the ac-
"sound field" -the whole musical event, vinyl at the stylus pressure point and the tual transition points, of which there
balanced naturally, and presented to the liquid layer on the disc surface. This should be two per revolution. As sug-
I

ultimate listener with startling realism temperature differential causes (by actu- gested, the slower the playing speed,
and an impressive stereo panorama. It al electron microscopy investigation) the easier it will be to distinguish the
will not sound like a professional mix on disorientation or cracking or injury to the transition points from the rest of the disc
one of the big labels, but if you're famil- surface molecular structure, just as you surface. O

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JULY 1977
25
 RC CIRCUIT QUIZ
BY ROBERT P. BALIN

Resistance -capacitance circuits are In ac circuits, the RC combination is However. whenever the RC circuit
not always as simple as they might used as a frequency -sensitive voltage has a different application, it seems to
seem. For example, in dc circuits, the divider or filter. And, in circuits involving acquire a different name for its function.
charging time of the capacitor, as con- both dc and ac components, it is used to To test your knowledge of RC circuits,
trolled by the resistance, is used to de- block the dc component.Other examples see if you can match the circuits (A to J)
termine oscillator frequency. could be given. with the functions (1 to 10).

1. Band Suppression
Circuit
2. Coupling Circuit c c c
3. Decoupling Circuit
4. Differentiator R R
5. Equalizer
6. Frequency Control
7. Integrator
8. Phase Shifting Circuit +
9. Timing Control

,
10. Tone Control A.

o-
, 1 , .
. ;
1 :

B. C. D.

R
C

0 C R
mew
R
R
C
C +
E. F. G.

-o
C4G.-M---

IN OUT

I.
R
I +

J.
o
IN
T OUT
o

H.

1-01.'CI-6'Y-8'H-L'0-9'0-9'f t 'd-C'e-Z'3 -1 -Sd3MSNV

213 POPULAR ELECTRONICS
 abili
software flexibility as well. MITS software,
including the innovative Altair BASIC Ian -
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8800b computer to be realized.
8K ALTAIR BASIC has facilities for variable
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functions, a concatenation operator, and
VAL AND STR$ functions to convert between
It Comes Naturally Wth strings and numbers.
The AltairTM 8800b Extended ALTAIR BASIC allows integer single
lt-e Nair 8800b from choice of four different memory boards and and double precision variables, automatic
MITS: thesecond gent many others.
err lior design of the microcomputer that line numbering and renumbering, user -
stafedit all. The mainframe that has the abil Reli -ability: defined string functions, PRINT USING for for-
he: everyone is demanding from miarocont The unique design features of the Altair matted output and a powerful ED' com-
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Expand- ability: reliable unit of its kinc. the Altair 100-pin bus,
include IF... THEN ... ELSE, LIST and DELETE
Its Altair 8800b power supply and one the now- standard design used by many imi-
program lines, SWAP variables and Trace On
piede, 18-slot motherboard allow efficien- and Off for debugging.
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optors. All Altair PC boards are designed tc the Altair 8800b isolatesand fitters front panel Extended BASIC with the additional capa-
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Whether you buy an entire system up front os Flex -ability: of real world problems.
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The configuration you need with the com- increasing microprocessor market requires ment system for the Altair 8800b, includes

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 Advanced Electronics

The best way to qualify for top positions

If you and top pay in electronics is obviously

with college -level training. The person
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the average technician who has been on

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A regular college engineering pro-
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teresting and useful part of your train-
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CREI programs give you a practical
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23 POPULAR ELECTRONICS
: areer Training at Home

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 Julian Hirsch HIRSCH /HOUCK LABORATORIES

Audio Reports

NOISE FILTERING FOR HI -FI

From high fidelity's earliest days, audiophiles have The wider bandwidth of LP records was fortunate-
faced the problem of dealing with the various ef- ly (and not accidentally) combined with low -noise
fects that we lump together under the heading of vinyl record materials so that the full frequency range
"noise." Noise is defined in the current ANSI stand- could frequently be enjoyed without too much distur-
ard as "unwanted disturbances super- imposed upon bance from noise. Nevertheless, even as records and
a useful signal that tend to obscure its information playback systems were improved, one's enjoyment of
content." In the case of sound reproduction systems, a wide-range recording was increasingly likely to be
this is modified to exclude harmonic, subharmonic, marred by extraneous noises. The fixed filter, being
and intermodulation distortion products, and flutter by far the cheapest "cure," continued to be offered as
and wow. a solution to this problem, although it usually solved
For most hi -fi listeners, noise falls into two broad nothing at all.
categories: high- frequency hiss or scratch and Unlike the situation with 78's, the recorded materi-
low- frequency noises, such as rumble or hum. All are al on an LP disc usually had useful energy up to
essentially steady-state effects, though they are usu- 10,000 Hz or higher. Cutting off the noise above
ally random in nature. Another category includes im- 10,000 Hz was of no help, since the change could not
pulse noise, composed of discrete pulses that occur at be heard by most people. Cutting off an octave lower,
regular or irregular intervals, such as automobile - at 5000 Hz, might produce a noticeable lowering of
ignition interference and record ticks or pops. the hiss level, but would certainly dull the program
To some degree, all of these forms of noise are pres- to an undesirable degree. The low- frequency noise
ent at all times in reproduced music, and eliminating problem was much less severe. For one, most of it
or reducing their objectionable qualities has been the was under the listener's control, in the sense that us-
goal of many talented engineers for decades. No pan- ing a better turntable would eliminate much of the
acea has yet been discovered for noise, but by attack- rumble at its source. Since most speaker systems
ing the problem on several fronts, it has been possible have considerably reduced output at very low fre-
to greatly reduce its audible effects. quencies, only the unfortunaTe combination of a poor
The basic problem is that the noise energy and the turntable, good speaker system, and high listening
music program occupy the same frequency spectrum, level was likely to result in a disturbingly high rum-
often simultaneously. Noise may extend well beyond ble level.
the program bandwidth or, as in the case of power We have been referring to filter action as "cutting
line hum, may occupy a small discrete portion of the off" at a certain frequency. If filters worked that way,
spectrum. The more successful noise -reduction sys- they would be much more effective. Unfortunately, a
tems operate by virtue of achieving a greater reduc- real filter, the simple type used in home entertain-
tion of noise than of program content, though some ment electronic products, attenuates the response
sacrifice of the latter is unavoidable. gradually, on both sides of its cutoff frequency. Most
The simplest, oldest, and least-effective anti -noise filters used in hi -fi amplifiers or receivers have a cut-
technique is to use fixed low -pass or high -pass filters off slope of 6 dB /octave (which requires only a single
to attenuate noise energy outside the main spectrum resistor and capacitor, hence its popularity). The ef-
of the program bandwidth. If bandwidth is limited fect of the filter begins more than an octave below the
(as in the case of 78 -rpm records or AM radio) it is cutoff frequency, at which point its response is down
possible to cut off most of the hiss with little loss of 3 dB. By the time the frequency has gone an octave or
program quality. The shellac -based 78 -rpm phono- more above the cutoff point, the rate of attenuation
graph records were noted for their high "scratch" approaches its ultimate value of 6 dB with each oc-
level, and a fixed filter cutting off above 3000 or 4000 tave increase (doubling of frequency).
Hz could be very helpful. Since turntable rumble was In fact, the typical filter response curve is virtually
concentrated at frequencies below 100 Hz, a filter identical to the treble tone control response with the
cutting off at that frequency could clean up the bass control set to minimum. The filter switch is thus a
reproduction without too much loss of content. convenient substitute for the tone control-but it is
32 POPULAR ELECTRONICS
no more effective as a noise -reducing device! A simi- end, rumble cannot be heard when the program is
lar situation exists at the low frequencies, with many loud or contains strong low- frequency material.
rumble filters beginning to cut the frequency re- It would seem logical to use a high -cut (low-pass)
sponse as high as 150 or 200 Hz. Fortunately it is pos- filter whose operating frequency and /or slope are
sible, by selecting a cutoff frequency between 50 and controlled by the program so that its filtering action
100 Hz, to make a worthwhile reduction in rumble occurs only under conditions that allow the hiss to be
without undue loss of program content because most heard. This logic is correct, but there is the problem
recorded music has little energy below 100 Hz. of selecting the dynamic characteristics, including
For better results, filters can be made with a sharp- the basis for filter operation, its actual response char-
er cutoff action so that a greater proportion of noise acteristics, and the rate of attack and decay of the fil-
can be removed without harmful effects on the pro- tering. Failure to do this correctly will result in audi-
gram. It is not too expensive to build filters with a 12 ble swishes and other clues that the filter is working;
dB /octave slope, and in some active filter configura- a noise reduction device whose action can be heard is
tions the cutoff "knee" can be made much sharper so not of much value.
that program material will be less affected. Some of There are a handful of add -on noise -reduction sys-
the better amplifiers and receivers do have such fil- tems that truly do a fair-to -good job of minimizing
ters, and if their cutoff frequencies are well chosen noise without any noticeable effect on program mate-
(and preferably selectable) they can be useful. rial. A new NR accessory, announced by SAE recent-
Nevertheless, no fixed filter, no matter how steep ly, even claims to remove ticks and pops from record
its attenuation slope or where its cutoff action begins, reproduction. But these are accessories.
can do a really effective job of noise reduction with- As strongly implied, the fixed filters built into most
out impairing program quality. A number of ingeni- receivers and amplifiers, especially those having 6-
ous dynamic filters have been developed in which dB /octave slopes, are virtually worthless as noise -
the attenuation and the frequency at which the filter reduction devices. In spite of this, many receivers
becomes effective are controlled by the program it- and amplifiers above the lowest price ranges include
self. The psychoacoustic phenomenon of masking is some sort of "filter," presumably because their de-
used in the design of these filters. High-frequency signers feel that it is expected of them. Perhaps a
hiss is audible only in the absence of high- frequency counter -trend is under way, since we noted with in-
program content; when the music is loud or contains terest that Radio Shack's deluxe Realistic Model
appreciable high-frequency energy, the hiss is STA -2000 receiver, reviewed in this issue, eschews
masked and cannot be heard. Similarly at the low all filters. We did not miss them for a moment.

REALISTIC MODEL STA2000 STEREO RECEIVER

Company's top -of-the -line, 75-W/channel receiver boasts notable features
and smooth performance.
and weighs 40 lb (18.2 kg). Supplied
with genuine walnut- finished end plates,
the receiver is catalog priced at $499.95.

General Description. A row of col-

ored indicator lights above the dial
scales illuminate to identify the selected
input (AM, FM, PHONO, AUX1 , Aux2) and
when a stereo FM station is being re-
ceived. Two small meters above the dial
scales monitor the output power of the
audio channels. The meters are calibrat-
ed at decade intervals from 0.1 to 100
watts, based on 8 -ohm loads.
Radio Shack's knobs and switch buttons. A large clear In addition to the input SELECTOR
Model STA -2000 glass window, behind which the dial switch, there are BASS and TREBLE tone
heads the "Real- scales are angled back for better visibil- controls with 21 detented positions, in-
istic" brand's list ity, dominates the upper two- thirds of cluding a FLAT setting at the center, and
as its top AM/ the panel. All controls, except the large a BALANCE control with a center detent.
stereo FM receiver. Its amplifiers are rat- tuning knob, are located on the lower The volume control operates in steps
ed to deliver 75 watts /channel into 8- third of the panel. The single tuning me- with 41 detented positions. Tone con-
ohm loads at less than 0.25% total har- ter indicates center-of- channel for FM trols are concentric, permitting individual
monic distortion (THD) from 20 to and relative signal strength for AM. channels to be adjusted.
20,000 Hz. The front panel is satin -fin- The receiver measures 19'W x Eight pushbutton switches are ar-
ished aluminum with matching control 161/z"Dx67/s "H (48.3 x 41.9 x 17.5 cm) ranged in a two -row matrix. The upper

JULY 1977 33
 IQ
1,1' phono inpu` at 1000 Hz didn't overload
_ I

AUDIO OUTPUT
until a very high 220 mV was reached.
The bass tone control had a variable

:.=IÌCi /:
0 dB =1 VOLT
10 IHF USABLE SENSITIVITM''-"-WIIIMINEME®
now TAPE -OUTPUT JACKS
turnover frequency. It provided a moder-

®
MONO:II.6dB (2.I6V)
-20STEREO:17dBf(4.OYV) =H/i/ ate boost o- cut below 100 Hz at partial

i
11 40
50:
H 7.
-
_
/////
::
REALISTIC STA -200,0

/H/HHH/
//H//// ///H/:HH/H////
//H/
+ DISTORTION
_ . settings, with negligible effect at higher
frequencies. The turnover frequency in-
creased to about 500 Hz at the control's
extremes. The treble control character-

11411MMMM ~ -/`
W
c
istics were hinged at about 3000 Hz.
60
,-
R
Il= RIAA phono equalization was flat within
-70
... .... .
NOISÉ 7 .
-__ ±0.5 dB from 60 to 20,000 Hz, dropping
slightly at lcwer frequencies to -2 dB at
50dB QUIETING SENSITIVITY
MON0:13.5dB1 (2 6pV)AT 1.1% THD
STEREO: 35.5dBf (32pV)AT 0.4% THD

MIME - --
MONO
STEREO
30 Hz. Because the phono preamplifier
_!
20
ili5
40
:///::i
50 60 70 80 90 100
stage effectively isolates the cartridge
INPUT dBf from the feedback components, the pho-
no response was completely unaffected
Noise and sensitivity curves for FM section of Realistic receiver. by the cartridge inductance.
The loudness compensation boosted
row is for switching in and out an FM nal areas. One of the two accessory ac only the low frequencies as the volume
MPX FILTER (reduces noise in stereo re- outlets on the rear apron is switched. control setting was reduced. The boost
ception by partially blending the chan- at normal listening levels was slight,
nels at higher audio frequencies), FM Laboratory Measurements. Dur- avoiding the unnaturally heavy sound
MUTE circuit, MONO /STEREO mode, and ing the one -hour preconditioning of the that is typical of most loudness- compen-
LOUDNESS compensation. The lower amplifier at one -third rated power, the sation systems. The power meters pro-
row of switches contains switching for a metal cover above the output transistors vided only a rough approximation of the
20 -dB audio ATTENUATOR (for temporary became quite warm, but the receiver as actual output, with typical errors being
interruption), A and B SPEAKERS selec- a whole remained cool. The outputs of 50% to 100%. They had a fairly slow re-
tion, and POWER. Two lever switches are the amplifiers, when driving 8 -ohm loads sponse time and were well damped, fol-
provided for controlling the tape record- at 1000 Hz, clipped at 90 watts /channel. lowing average program levels to our
ing functions for two tape decks. The Into 4- and 16 -ohm loads, the output satisfaction.
DUBBING switch crossconnects the was 106 and 55 watts, respectively. The FM tuner section had an IHF sen-
decks for copying a tape from either The 1000-Hz THD was less than sitivity of 11.6 dBf (2.1 µV) in mono and
deck to the other or connects both decks 0.01% from 0.1 to 20 watts. It increased 17 dBf (4.0 .tV) in stereo. The steep li-
for recording from the program source to very slowly to 0.05% at 80 watts. The IM miting curve yielded 50 dB of noise qui-
which the SELECTOR switch is set. The distortion was between 0.03% and 0.1% eting at only 13.5 dBf (2.6 µV) in mono,
MONITOR switch connects the playback from 0.1 to 80 watts. At outputs of a few with 1.1°/0 THD, and 35.5 dBf (32 µV) in
from either deck or the selected source milliwatts, the IM distortion increased to stereo, with 0.4% THD. The 1000-Hz
to the receiver's audio amplifiers. several tenths of a percent. distortion was about 0.08% in mono and
On the rear apron of the receiver are At the rated 75 -watt output, the distor- 0.32% in stereo at a 65 -dBf (1000 µV)
insulated binding posts for the two pairs tion was between 0.02% and 0.05% input. The stereo THD, with L -R chan-
of speaker systems that can be accom- over most of the audible- frequency nle modulation, was 0.75% at 100 Hz,
modated. (The connectors are excep- range and never exceeded 0.09 %. It 0.1% at 1030 Hz, and 0.2% at 6000 Hz.
tionally easy to use and do not require was much the same at lower output The S/N was 72.5 dB in mono and 69
the wire to be wrapped around the powers, measuring about 0.01% at mid- dB in stereo.
posts.) Their functions are duplicated by dle frequencies and from 0.1% to 0.14% The FM frequency response had a
two pairs of phono jacks for speaker at 20,000 Hz. Through the Aux input, the slight dip in the midrange and high -fre-
system cables equipped with phono amplifier's sensitivity was 50 mV for a quency response, plus the usual drop at
plugs. The various signal input and out- reference 10 -watt output with a 74 -dB 15,000 Hz due to the multiplex pilot car-
put connectors are phono jacks, and the S/N ratio. The phono sensitivity was rier filter. Overall, the response was still
two sets of tape recorder connectors are 0.83 mV with a 66 -dB S/N ratio. The within ±1 dB from 30 to 12,500 Hz,
Cuplicated in DIN sockets. Two sets of
auxiliary outputs are also included.
Preamplifier outputs and power amplifier 10
inputs are brought out to separate pho- FREQUENCY RESPONSE

no jacks that are joined together by re- 0

movable jumper links. There are anten- 10 _

na terminals for 75- and 300-ohm FM REALISTIC STA- 2000 Frequency response
antennas as well as a wire -type AM an- '0 STEREO FM
AVERAGE BOTH CHANNELS and crosstalk
tenna. There is also a fully hinged and averaged for both
pivoted AM ferrite rod antenna. The line SO channels in stereo FM.
cord has a capacitive coupling clip that
0 CROSSTALK
can be connected to one of the 300 -ohm
FM antenna inputs so that the power line 50
20 50 IOO 200 500 IK 2K 5K IOK 20
can be used as an antenna in strong sig- FREQUENCY IN Hz

34 POPULAR ELECTRONICS
 1.0
I 1. I II
REALISTIC STA -2000
1 1

REALISTIC STA- 2000 Am

n
mo

0.5 =11 NS REF-HENCE POWER (73w1

HALFPOWER( -3A81 111

-- -- H: TO AL HARMONIC DISTORTION
60/ 7000 0: (4.11 IM DISTORTION
0.5
LOW POWER( -10ÁB) "

0.2
z
O 02
z O
O
0.1
N 0.1
cc 44,
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O 71
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.05
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ZIMIUMEMEIMMEIIIIIIIIIII
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1ninggiillirn11

MEN
.005
.005

002
0.1 0.2 05 4 5 10 20 10 00 002
20 100 200 500 14H1 7LH: 5112 10 441 20
CONTINUOUS AND EQUIVALENT SO
MH
SINE -WAVE POWER OUTPUT PER CHANNEL IN WATTS FREQUENCY IN Hz (CYCLES PER SECOND)

Total harmonic distortion and 60/7000 -Hz distortion. Harmonic distortion at three power levels.

down about 3.7 dB from midrange levels lectivity was 76 dB, and adjacent -chan- 4500 Hz and 3.5 dB at 20 Hz, from the
at 15,000 Hz. The stereo channel sepa- nel selectivity was 4.6 dB. Muting and midrange levels.
ration was very uniform, about 35 dB automatic stereo switching thresholds
over most of the audio range. It was a were identical at 17.2 dBf (4 µV). The User Comment. There are some in-
very good 27.5 dB at 30 Hz and 31.5 dB 19 -kHz pilot carrier leakage into the au- teresting in-use observations to be
at 15,000 Hz. dio outputs was -70 dB, and tuner hum made concerning this receiver that don't
FM capture ratio was 1.75 dB at 65 was a very low -75 dB. The AM tuner show up by examining specifications.
dBf and 1.9 dB at 45 dBf (100 µV) in- section appeared to be relatively sensi- For example, unwanted noises and
puts. The AM rejection was an excep- tive, with a notable freedom from buzz- switching transients have been elimi-
tional 83 dB. Image rejection also mea- ing noises, and a wider-than -usual fre- nated with notable success. This is
sured 83 dB. The alternate -channel se- quency response that was down 6 dB at accomplished by effecting a slight delay

IN WIRE- WRAPPING HAS THE LINE...

HOBBY -WRAP -30 WIRE- WRAPPING, STRIPPING, UNWRAPPING TOOL FOR AWG 30 (.025 SQUARE POST)

STRIP WRAP UNWRAP

OK MACHINE & TOOL CORPORATION

3455 CONNER STREET, BRONX. NEW YORK, N.Y 10470 0.5.A PHONE (212) 9944800

TELEX: 125091 TELEX: 232395

CIRCLE NO 33 ON FREE INFORMATION CARD

JULY 1977 35
 after power is applied, whereupon a re- Realistic has chosen to omit some volume- setting place previously used.
lay connects the speakers to the output "features" usually found in receivers of Comparing the actual measured per-
transistors. Furthermore, when the FM the Model STA-2000's price range that formance of this receiver to that of simi-
muting switch is activated, FM tuning ac- are of little value in any receiver such as lar products we have evaluated, we find
tion is completely free of transients and low- and high -cut audio filters. Unless that the Model STA -2000 is at the least a
noise bursts. such filters have cutoff slopes of 12 dB/ competent performer in every respect
The output transistors are protected octave or more, they are useless for and outstanding in many. It has the un-
against damage from overload, includ- their intended purpose. However, the mistakable "sound" of a good control
ing short circuits, by a circuit that si- tape recorder dubbing connections, and amplifier, giving the sense of not having
lences the receiver until it is reset by the separate preamplifier outputs and a device between the source and the
turning off the power for a few moments power amplifier inputs that are indeed speakers.
and then turning it on again. We verified useful have been included. The same The physical smoothness and preci-
the effectiveness of the overload protec- for its FM multiplex noise filter. We par- sion "feel" of the controls are consistent
tion by driving the receiver into shorted ticularly like the large pushbutton with the receiver's excellent perfor-
outputs, which immediately shut off the switches as compared to rotary mance. Though it is not a "super- power"
amplifiers without damaging them. It is switches. They're most convenient to receiver, the Model STA -2000 is more
also thermally protected against exces- use. The 20 -dB attenuator switch is a than powerful enough for the majority of
sive operating temperatures, although nice touch, permitting the user to lower users and is a very good value.
we never reached such a condition. volume temporarily without losing the CIRCLE NO 102 ON Riff INFORMATION CARD

KOSS MODEL K/145 STEREO HEADPHONES

Comfortable to wear with fine bass performance in moderate price range.
brown vinyl and come with a matching the larger excursions of the diaphragm,
padded headband. A separate knurled to between 0.6% and 0.9% in the 20-
wheel protruding slightly from each ear - to- 100 -Hz range. We also measured the
cup allows independent volume level distortion with the drive level increased
adjustment in the left and right channels. to 1 volt, which corresponds to a 112 -dB
The cords that attach to the earcups output at 1000 Hz. The THD at this level,
come down to form a Y joint about 2' (60 although far in excess of normal listen-
cm) from the earcups before joining to ing levels, was 0.3% to 0.8% at most fre-
the coiled cord that goes to the driving quencies above 100 hertz and 1.8% at
amplifier. The total length of the cord is 20 hertz.
10' (about 3 meters). The phones weigh The impedance of the phones was a
1 lb (454 g), less cord. Price is $45. constant 90 ohms from 20 to 20,000 Hz
with the level controls set to maximum.
Laboratory Measurements. We At the center positions of the controls,
tested the phones on a modified ANSI the impedance increased to 700 ohms,
headphone coupler, the type used by while at the minimum settings, it was
Koss for making in -plant measurements. about 1000 ohms.
The bass frequency response was very
flat and smooth, confirming the effec- User Comment. In our use tests, we
tiveness of the "Pneumalite" ear cush- found these snug- fitting phones to be
ions in sealing the phones to the ears. comfortable to wear, even over pro-
a. The output varied by only ±1.5 dB from longed listering periods. We noted that
Heading a new 20 to 300 Hz. the sound quality is pleasant and listen -
line of low -cost At higher frequencies, the output able throughout, though it lacks the bril-
"Slimline" stereo dropped at about a 6 -dB /octave rate, to liance or crspness exhibited by, say,
headphones from -20 dB in the 3000 -Hz range. The usual electrostatic types. (The latter are much
Koss is the Model high -frequency response irregularities costlier, of course.) However, we ob-
K/145. This circumaural headphone were visible above 4000 Hz in our chart served no apparent loss in the high -fre-
features rectangular ear cushions that plots, including péaks at 5500 and quency range. The bass and lower mid-
exclude most outside sounds. Each ear - 14,000 Hz. These irregularities can be range were strong and solid.
cup contains a dynamic driver with a 38- due, at least in some degree, to the cou- In an overall evaluation of perform-
mm polyester diaphragm. The frequen- pler and cannot be definitely attributed ance, we find these new Koss phones to
cy range of the phones is specified at 20 to the headphones themselves. be fine performers, though sounding a
to 20,000 Hz. Impedance is rated at 90 With a 0.25 -volt drive at 1000 Hz ap- bit "soft" fo our personal tastes. But
ohms at 1000 Hz, while sensitivity is plied through a source resistance of 100 other listeners may indeed prefer it this
specified at 0.25 volt at 1000 Hz (or 0.11 ohms, the phones delivered their rated way. Since headphones, like speaker
volt rms with pink noise) for a 100 -dB 100 -dB SPL output. The total harmonic systems, are best judged subjectively by
sound pressure level (SPL). Harmonic distortion at this level was between 0.1% the listener, we strongly recommend a
distortion is claimed to be less than and 0.2% from 300 to 10,000 Hz, which personal audition of these comfortable,
0.5% at 1000 Hz and 100 dB SPL. is well below the rated 0.5 %. At lower relatively inexpensive phones.
The phones are finished in textured frequencies, the THD increased, due to CIRCLE NO 103 ON FREE INFORMATION CARD

36 POPULAR ELECTRONICS
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Miami Lakes Florida 33014 USA

CIRCLE NO 22 ON FREE INFORMATION CARD

JULY 1977 37
 Automotive Developments
HIGHLIGHTS
ws
person sought is in a room with a sensor, his or her tran-
sponder unit responds, whereupon a signal goes back to
Ford Motor Company recently announced plans to use the console, giving the location and telephone extension
the resources of major semiconductor producers to help (if any). The inquirer can then e:ther go to the area in-
in the design of future automotive models. Specially de- dicated or call on the extension. Shades of 1984!
signed large -scale integrated circuits and microcomput-
ers will shortly control many engine functions. Two new
concepts which will be pioneered by Ford in 1978 in- Digital Watch Firsts
clude an electronically controlled carburetor and an Intertime Corporation has introduced the latest in diving
electronic engine control system for spark timing and equipment, an underwater digital watch. Named "Mari-
exhaust gas recirculation. The new devices, to be in- time," the watch uses LED's to display month, week,
stalled on a limited volume of 1978 models, are intended date, hours, minutes and continuous counting seconds.
to improve fuel economy, emissions and performance. Activation of a single button displays red numerals de-
Chrysler and General Motors have also announced signed for easy underwater visibility, and a ratchet be-
plans to use microprocessors in some auto models. zel graduated in minutes is provided for elapsed time
reference. The housing is Swiss made, produced from a
solid block of stainless steel. It's equipped with double
TV Color Organ
"0" rings to prevent water leakage and fogging, and has
A new entertainment system developed by Atari, called been factory tested to a depth of 600 ft. $250.00.
"Video Music," electronically synchronizes images and
colors to music from a stereo receiver. A cable which
connects the Video Music to a stereo receiver and a Another innovative digital watch to be introduced is the
switch box connected to the vhf antenna terminals of a "programmable message" model from the Solid State
television set allow the music signals to be conducted di- Products Division of Hughes Aircraft Company. The
rectly to the video screen. Five front -panel potentiome- watch module features a personalized five -word, five -
ters and twelve pushbuttons on the Video Music enable letter- per -word message programmed by the wearer and
the viewer to adjust the color, shape, brightness and displayed in an electronic readout. The message can be
size of the geometric image, producing an enormous changed as desired by the user, a procedure which takes
number of possible picture combinations which pulse less than five minutes. The five standard functions of
and beat to the rhythm of the music. Uses five IC's, two month, date, hour, minute and second are also included,
transistors and twelve diodes, and comes with an FCC- with five LED's providing the letter, symbol and num-
approved r-f switch box. ber readouts. A spokesman for the company suggests
that the watch can be used for important appointment
reminders or medical instructions, among other applica-
RCA To Market 4-Hour VTR tions.
RCA has announced plans to market a home video -tape
recorder made by the Matsushita Electric Industrial Co. Solar -Powered Calculator
of Japan. The new video tape recorder, called "VHS,"
will have a mode switch for either 2- or 4 -hour recording The Sun Man," a new solar hattery-powered calcula-
with the same cassette, vhf and uhf tuners, and a clock tor recently introduced by Sharp Electronics, is be-
for automatic recording. Moreover, a company spokes- lieved to be the smallest such instrument on the market.
man said that optional microphones and cameras will be With dimensions of 0.35" thin x 2.6" wide x 7.5" deep (9
made available to allow consumers to produce home mm x 66 mm x 109 mm), the solar-powered calculator
movies on the video tape cassettes. Thus, a VTR war is said to have a longer life span than the ordinary cal-
for consumers' hearts appears to be shaping up between culator battery, needing only two hours of window light
the VHS models and Sony's Betamax models, the lat- to recharge. It performs six functions, and uses a liquid
ter, a two-hour video recorder to be marketed by the Ze- crystal display. $99.95.
nith Corp. Too bad that standards are dissimilar.
Antique -Radio Manuals
An R -FPeople Finder To assist antique -radio collectors in the usually frustrat-
The Trakatron "Silent People Finder" by Intersonics ing search for technical literature, Supreme Publications
Corp., New York, NY, is an electronic system that lo- has formed a department which will buy and sell old
cates people in an office or plant without paging them. technical data. Original Rider manuals and old Sams,
Each person has a transponder and is assigned a button Supreme, and many factory service manuals are on
on a console locator. A sensor is placed in certain de- hand, some dating back to the 20's. For information
sired areas. When the console's button is pressed, the write to Supreme Publications. 1760 Balsam Rd., High-
proper signal goes throughout the covered areas. If the land Park, IL 60035.

38 POPULAR ELECTRONICS
 HOW TO SAVE HUNDREDS
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PAINLESSLY.
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equipment that gives you professional quality and precision
at very unprofessional prices. Each unit can save you
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For more information on these, or any other
CSC products, see your dealer or write
for our catalog and distributor list.

SAVE MONEY AND TIME

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This precision all -in-one unit
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Saves money by eliminating test all kinds of equipment, with 1Hz-
lead damage and heat 100kHz signals. Low-distortion sine
damage to components. waves, high -linearity triangle waves,
Lets you re-use parts over fast -rise -time square waves. Five
and over again, to save decade ranges, accurate to 5% of dial
even more. All for just setting, with variable 100mV-10V P -P
$54.95* output and constant 600 -ohm
impedance. At $69.95* it's a lot of
signal for very little money.

SAVE MORE MONEY AND TIME

=5G
WITH DESIGN MATE 3
Accurate R/C bridge helps you use CONTINENTAL SPECIALTIES CORPORATION
"bargain" components. Quickly and
easily measures resistance 10 ohms -10
meg; capacitance 10pF -112F -both in
decade ranges to within 5% of dial EASY DOES IT
setting. Simple, 2- control operation and 44 Kendall Street. Box 1942
positive LED indication make New Haven, CT 06509. 203 -624 -3103 TWX: 710-465 -1227
West Coast office: Box 7809, San Francisco, CA
measurements in seconds. At $59.95* 94119 415 -421 -8872 TWX 910- 372 -7992
it pays for itself in no time. Canada Len Finkler Ltd.. Ontario
Mexico: ELPRO, S.A., Mexico City 5- 23-30 -04
© 1976, Continental Specialties Corp. *Manufacturers suggested list. Prices and specifications subject to change without notice.

CIRCLE NO 10 ON FREE INFORMATION CARD

JULY 1977 39
 t tvocsf
s
t4 G

i
rt
pow 1'X
stti<l IN fcv
ea',trc.
ct

fti8-lî

crer

The 9 -inch screen of the CT-VM monitor ($175) shown here with Southwest's new CT-64 illustrates the terminal's 64- character lines, switchable control
character printing, and word highlighting. At just $500 for both, these matching units- provide a complete CRT terminal with fuil cursor control, 110 -1200 Baud
serial interface, and many other features.

Now $325 buys a 64- character terminal kit

Our new CT-64 terminal kit gives you scrolling, full The CT-64's features include:
cursor control, 128 -character ASCII display (with both 64 or32 characters per line (16 lines)
upper and lower case), and two 1K memory pages. It's Premium display with both upper and lower case
usable with any 8 -bit computer. letters, and descenders (g, j, etc.)
Add our optional fully assembled 12 MHz CT-VM Two 1K pages of 8 -bit memory
monitor for another $175 and you'll have the best CRT Scrolling or page mode operation
terminal buy offered anywhere. 32 control character decoding
Prints control characters (selectable)
The CT-64 gives you full cursor control, home -up and - 128 -character ASCII set
erase, erase to end of line or end of frame, cursor on /off, 110 /220 Volt 50 -60 Hz power supply
screen reversal, scroll or page, solid or blinking cursor, Highlights words with reversed background
page selection, and end -of -page warning beeper. Optional 9 -inch monitor with matching cover available
Complete with keyboard, power supply, 110 -1200
Baud serial interface, and case

Okay, Southwest, I know a bargain when see

I it or BAC # Exp. Date
Enclosed is $500 for the whole works
or MC # Exp. Date
(CT-64 terminal plus 12 MHz CT-VM monitor)
C Here's $325 for the CT-64. Name Addrrss
C Send only data for now. Southwest Technical Products Corp.
C Send me your $395 MP -68 computer kit. City State ZIP 219 W. Rhapsody, San Antonio, Texas 78216
CIRCLE NO. 48 ON FREE INFORMATION CARD

www.americanradiohistory.com
AmericanRadioHistory.Com
 COSFIRE
I1 ó
-
Popular Electronics'

TESTE
BREAKTHROUGH
PROJECT
JULY 1977

BY JOSEPH A. WEISBECKER

PART IV:

Build the PIXIE Graphic Display

Adding one chip to the Elf provides complete
video interface and animated graphics
capability for less than $25.
Ifyou own an Elf microcomputer (see parts distributors. (A complete kit is Pixie graphics system is added. In this
POPULAR ELECTRONICS August 1976) available; see Parts List.) The two other article, we will show you how to install
or are planning to build one soon, the IC's in the optional add -on system are and program the Pixie system to pro-
addition of a single IC and a handful of for a crystal oscillator that allows the duce this type of graphics.
support components, and a change in graphics IC to generate the correct TV
the crystal frequency, can give you Pixie horizontal and vertical sync pulses. Some Details. The unique Pixie
graphics. The entire graphics system is The photo at the top of this page illus- graphics system employs the direct
built into the new CDP 1861 LSI chip trates what can be done with the original memory access (DMA) capability built
that sells for less than $20 from RCA 256 bytes of memory in the Elf when the into the 1802 microprocessor in the Elf

The basic Elf project orginally published in the

August 1976 issue of POPULAR ELECTRONICS is shown
at left with Pixie components added. Elf II is a complete
kit including a pc hoard, hexadecimal keypad, Pixie
graphics components and expansion bus (see Parts List).
JULY 1977 41
 _6
, _7

JCOn OCCF TABLE I-TEST PROGRAM

r r
^,6 .;C17
Label M Bytes Comments
F +
Start 0000 90 B1 82 R1: ,R2.1=00
0003 B3 B4 R3.0,R4.0 =00
0005 F8 2D A3 R3.0= (main)
0008 F8 3F A2 R2.0= (stack)
000B F8 11 Al R1.0= (interrupt)
000E D3 P =3 (go to main)
Return 000F 72 restore D, R2 +1
0010 70 restore XP,R2 +1
Fig. 1. Memory addresses of Interrupt 0011 22 78 R2 -1, save XP <t M2
bytes mapped onto TV 0013 22 52 R2 -1, save D (ì M2
screen in sample program. 0015 C4 C4 C4 no -op (9 cycles)
0018 F8 00 BO
001B F800A0 R0= 0000(refresh ptr)
Refresh 001E 80 E2 D= R0.0
to work in conjunction with the new
8 DMA cycles (R0 +8)
graphics IC. This allows you to display 0020 E2 20 AO R0- 1,R0.0 =D
any 256 -byte segment of memory on a 8 DMA cycles (R08)
CRT monitor or TV receiver. The output 0023 E2 20 AO RO- 1,R0.0 =D
of the new chip is a 1 -volt composite 8 DMA cycles (R0 +8)
video /sync signal. 0026 E220A0 RO- 1, R0.0 =D
The selected segment of memory ap- 8 DMA cycles (R0 +8)

pears on- screen as an array of small 0029 3C lE go to refresh (EF1 =0)

002B 30 0F go to return (EF1 =1)
squares that represent individual memo-
Main 002D E2 69 X =2, turn TV on
ry bits. If a memory bit is a 1, the appro-
002F 3F 2F wait for IN pressed
priate square will be white, while if a bit 0031 6C A4 set MX,D,R4.0= toggles
is a 0, the square will be dark. Changing 0033 37 33 wait for IN released
the bit pattern within the memory will 0035 3F 35 wait for IN pressed
change the pattern that appears on- 0037 6C set MX,D= toggles
screen. You can store several different 0038 54 14 set M4 =D, R4 +1
bit patterns (pictures) in memory and, 003A 30 33 go to M33

PIXIE LOC COSMAC CODE LNNO

1
SOURCE LINE

.. AN 1802 ANIMATION PROGRAM by E. DEVEAUX

2

ANIMATION 78 3
4
5
BEGSFT.#78
..
.. ADDRESS OF FIRST LINE SHIFTED.
THIS PROGRAM PROVIDES VARIABLE SPEED
6 .. ANIMATION OF THE IMAGE LOCATED AT #78 to
PROGRAM 7
8
..
..
#F7 IN MEMORY.
SPEED CONTROL IS PROVIDED BY INPUT SWITCHES.
GHI RO ..ZERO HIGH ORDER OF
00 90 9
01 B1 10 PHI R1 ..R1 R2 R3.
02 B2 11 PHI R2
03 B3 12 PHI R3
04 B4 13 PHI R4 ..R4 POINTS TO REFRESH
BY EDWARD C. DEVEAUX 05 A4 14 PLO R4 ADDRESS
06 F816 15 LDI A.0(INTR2T)
08 Al 16 PLO R1
THE PROGRAM given here can be 09 F813 17 LDI A.0(STACK)
used with the Pixie version of the OB A2 18 PLO R2
OC F831 19 LDI A.0(MAIN)
Elf microcomputer to create animation PLO R3
OE A3 20
graphics using only the original 256 OF D3 21 SEP R3 ..GO TO MAIN LINE
bytes of memory. The interrupt routine 10 01020300 22 DC#01020300 ..STACK AREA
13 23 STACK ..* -1
uses the same timing as described in 24 04
previous Elf articles. However, a 25 ..THIS PROGRAM USES A MODIFIED VERSION
26 ..OF THE INTERRUPT ROUTINE THAT APPEARED
counter has been added to this rou- 27 ..IN COSMAC ELF PART 4.
tine, and we load the refresh address 28
29 ..A SHIFT ROUTINE HAS BEEN ADDED THAT MOVES THE
into RO from R4. The main line of the 30 .. STARSHIP FROM LEFT TO RIGHT ACROSS THE CRT.
program has been completely rewrit- 31
14 72 32 RETURN,LDXA
ten and contains shift, roll, and INPUT 15 70 33 RET ..CYCLES
switch read routines. 16 22 35 INTRPTsDEC R2 .. 2
17 78 36 SAV ..4 R5 COUNTS REFRESH
The shift routine shifts 16 lines of 18 22 37 DEC R2 ..6 CYCLES, USED TO
the display to the right one bit at a 19 52 38 STR R2 ..8 DETERMINE WHEN TO
lA 15 39 INC R5 ..10 SHIFT /ROLL.
time; bits shifted off the rightmost byte 1B C4 40 NOP ..13
are shifted back onto the display in the 1C 94 41 GHI R4 ..15 R4 TO RO

42 POPULAR ELECTRONICS
 X TAL
using software, display them succes- 13.579545 MHz 1.789773MHz,__,
I
l' TO 802, PIN I

sively onscreen to produce animation ef-

1

R4 R5 +5V
47011 47011
fects. Low -resolution alphanumerics can R6
IOK
also be created. 14 14
9
Since the basic Elf has only 256 bytes 0
5

of memory, we will show how to display 10

IC3 CI
7474
the entire memory on the screen. The
memory is mapped as shown in Fig. 1,
= IC2, 74L00 0
330DF

in an array of 64 spots wide (eight bytes 17

with eight bits/byte) by 32 spots high to

make a total of 256 bytes. 8 (B)

9
RUN ICI CLOCK (1802, PIN 39)
The byte at M(0000) is displayed at 4 CDPI861 10
TPA NO
the upper -left of the screen; each row on TPB
5
EFI
Fig. 2. Video display chip
the screen is equivalent to eight memory INT
3 connections are shown at (A),
bytes. Byte M(OOFF) appears at the bot- DMA OUT
2
RI
108
Optional circuit to replace
tom -right of the screen. SCA
21

22
SIN original Elf crystal is at (B).
SCI R2 JI
3 2K
D0 VIDEO
VIDEO
OUTPUT All resistors 1/4-watt, 10% tolerance:
Circuit Operation. The entire sche- DI
14

15
R I , R6- 10,000 ohms
R3
matic diagram for the Pixie graphics dis- D2
16 IK R2 -2000 ohms
D3
play system is shown in Fig. 2A. It con- 17
R3 -1000 ohms
sists of five components: the 1861 chip,
D4
18
R4,R5 -470 ohms
05
XTAL -3.58 -MHz crystal
a phono jack for the video output, and 06
9
20 24 Misc.-Printed circuit or perforated board; IC
three resistors. The circuit shown in Fig. D7 +5V sockets (one 24-pin, two 14 -pin); spacers;
2B may be used to replace the original II machine hardware; hookup wire solder; etc.
crystal used in the Elf microcomputer. Note: The following are available from Ne-
This is necessary because, to use the (A) tronics, 333 Litchfield Rd., New Milford,
CN 06776: kit including all of above Pixie
graphics display, the original crystal fre- "PIXIE" PARTS LIST components except those under "Misc." at
quency must be changed to approxi- C I- 330 -pF disc capacitor $24.95; complete Elf II kit (basic Elf plus
mately 1.760640 MHz to generate the ICI -CDP 1861 video IC(RCA) Pixie components and hexadecimal key-
IC2 -74L00 low -power quad 2-input NAND board), including pc board, keyboard sup-
correct TV horizontal and vertical sync
gate IC port IC's and expansion bus at $99.95, plus
pulses. Crystals of this frequency may 1C3 -7474 dual -D flip -flop IC $3.00 shipping. Connecticut residents, add
be expensive. The Fig. 2B circuit uses a J -Phono jack
I 7% sales tax.

high -order position of the first byte on 1D BO 42 PHI RO ..17 REFRESH ADDRESS
the line. lE 84 43 GLO R4 ..19
IF AO 44 PLO RO ..21
The 32 lines of the display can be 45
moved up one line by incrementing 20 80 46 GLO RO ..23
the starting refresh address by eight 21 80 47 GLO RO ..25
22 80 48 REFRESHIGLO RO .. 27
between refresh cycles. Decrement - 23 E2 49 SEX R2 .. 29 8 DMA CYCLES
ing register 4 (R4) allows the display 50
24 E2 51 SEX R2
to be rolled down. Hence, varying the 25 20 52 DEC RO
frequency of shifts or rolls varies the 26 AO 53 PLO RO 8 DMA CYCLES
54
animation speed of the displayed im- 27 E2 55 SEX R2
age. 28 20 56 DEC RO
29 AO 57 PLO RO 8 DMA CYCLES
Control of the speed is via the Elf's 58
conventional INPUT switches. Setting 2A E2 59 SEX R2
2B 20 60 DEC RO
all switches to zero and depressing 2C AO 61 PLO RO .. 8 DMA CYCLES
the INPUT pushbutton causes a hex 00 62
2D 3C22 63 BNI REFRESH .. ON EF1 REFRESH
to be read into location 13 (stack), in 2F 3014 64 BR RETURN .. IS OVER.
which case, there will be no move- 31
32
E2
69
65
66
MAINiSEX R2 .. RX 2
ment of the displayed image. Loading INP 1 .. TELL 1861 TO
67 TURN ON CRT.
any nonzero bit through the INPUT 68 .. SFREAD READS INPUT SWITCHESTO CONTROL
switches will animate the image. Any 69 ..SPEED OF SHIFTS /ROLLS.
70 ..INPUT SWITCH IS STORED AT STACK M(R2).
bits loaded are compared to the bits in 71 .

the low -order byte of register 5 (R5). A 72 ..INITIAL VALUE OF STACK IS ZERO AND THERE IS
73 ..NO MOVEMENT OF STAR SHIP UNTIL A NON ZERO BIT
shift or roll routine is initiated whenev- 74 ..IS INPUT.
er there is a match between the bits of 33 3F38 75 SFREADIBN4 CKSHIF .. IF NO INPUT GO SEE
35 3735 76 WTREADi84 WTREAD .. IF TIME TO SHIFT.
the low -order byte of R5 and the bits 37 6c 77 INP 4 .. READ INTO STACK.
in the byte read into location 13. Reg- 78
38 85 79 CKSHIF,GLO R5 .. GHI R5 VARY /SPEED
ister 5 is used to count the refresh cy- 39 F2 80 AND . OF STAR SHIP.
cles and is incremented by one every 3A 3233 81 BZ SFREAD SHIFT /ROLL BIT MATCH.
3C F800 82 LDI A.1(BEGSFT) ..BR ROLL 3061
interrupt cycle. 3E B9 83 PHI R9 ..ROLL NO SHIFT.

JULY 1977 43
 readily available 3.58 -MHz color -TV when the Elf is stopped with the RUN
crystal and frequency divider to gener- switch down.
ate 1.789773 MHz, which is close In the program shown in Table I, R1 is
enough for the 1861 chip to perform set to the address of the interrupt routine TABLE I1-SPACESHIP PROGRAM
properly. at M(0011), R2 is set to the address of
M Byte Sequence
The 1861 chip uses the same clock as the work area (or stack) used subse-
the 1802 µP chip to trigger internal quently for byte storage, R3 is set to the 0040 00 00 OC 00 00 00 00 00
counters to provide the TV -like compos- main program starting at M(002D), and 0048 00 00 00 00 00 00 00 00
ite sync at pin 6. The graphics display is setting P =3 causes a branch to 0050 7B DE DB DE 00 00 00 00
0058 4A 50 DA 52 00 00 00 00
directly refreshed from the memory 60 M(002D) with R3 as the program coun-
0060 42 5E AB DO 00 00 00 00
times each second, accomplished by an ter. The main program permits entry of
0068 4A 42 8A 52 00 00 00 00
interrupt request sent to the 1802 at the the bytes at any time via the Elf's toggle 0070 7B DE 8A 5E 00 00 00 00
same rate. switches. This permits you to see what 0078 00 00 00 00 00 00 00 00
When the 1802 receives the interrupt is happening to the CRT screen as 0080 00 00 00 00 00 00 07 E0
request, it temporarily stops the program memory bytes are changed. The pro- 0088 00 00 00 00 FF FF FF FF
it is executing and immediately gram loops on itself until an interrupt sig- 0090 00 06 00 01 00 00 00 01
branches to the interrupt routine previ- nal is generated by the 1861, activated 0098 00 7F EO 01 00 00 00 02
ously stored in memory. This branch oc- by the 69 instruction at M(002E). 00A0 7F CO 3F E0 FC FF FF FE
00A8 40 OF 00 10 04 80 00 00
curs when P is automatically set to 1 and Exactly 29 machine cycles after the
00B0 7F CO 3F EO 04 80 00 00
X s set to 2. The interrupt routine pro- initiation of the interrupt routine, the
00B8 00 3F DO 40 04 80 00 00
gram counter is always R1, which must 1861 requests eight sequential memory 0000 00 OF 08 20 04 80 7A 1E
be set to the address of the interrupt rou- bytes by pulling down the DMA-OUT 0008 00 00 07 90 04 80 42 10
tine before the 1861 is activated and (pin -2) request line for eight bytes (eight OODO 00 00 18 7F FC FO 72 1C
starts sending interrupts to the 1802. A machine cycles). This automatically 00D8 00 00 30 00 00 10 42 10
pulse from NO is sent to pin 10 of the causes eight memory bytes, addressed OOEO 00 00 73 FC 00 10 7B DO
1861, permitting this chip to start send- by RO, to be sequentially fetched and 00E8 00 30 30 00 3F FO 00 00
ing interrupts. A 69 instruction can be transferred to the 1861 via the data bus. 00F0 00 00 18 OF CO 00 00 00
Note that the C4 instructions at M(0015) 00F8 00 30 07 FO 00 00 00 00
used to generate the 1861 activation
pulse. The 1861 is always turned off are special no -op instructions that re-

INIMMII

The numbers in the program flow

84 LDI A.0(BF7GSFT)
3F F878
R9 ..R9=FIRST LINE chart (right) refer to the line numbers
41 A9 85 PLO
42 F810 86 LDI 16 ..TO SHIFT. in the program. The program can be
44 A6 87 PLO R6 ..SHIFT 16 LINES. set up to shift or roll, or shift and roll.
45 99 88 NXTLNEzGHI R9
46 BA 89 PHI RA ..SAVE ADDRESS OF 1st The program is loaded into locations
47 89 90 GLO R9 ..ON LINE IN RA 78 through F7. (Try using the program
48 AA 91 PLO RA
49 F807 92 LDI 7 ..R7mBYTES TO SHIFT -1. for the starship shown in Table II of
4B A7 93 PLO R7 the Pixie article.) Only the data loaded
4C 09 94 LDN R9
95 PHI R8 ..SAVE 1ST BYTE ON into 78 through F7 is shifted, but the
4D B8
4E 76 96 SHRC ..LINE IN R8.1 entire area from 00 through FF is
4F 19 97 NXTBYT.INC R9 ..POINT R9 TO NEXT BYTE. rolled.
50 09 98 LDN R9 ..LOAD NEXT BYTE.
51 76 99 SHRC ..SHIFT RIGHT. Loading the program exactly as it is
52 59 100 STR R9 ..STORE BYTE listed here will enable the shift routine
53 27 101 DEC R7
54 87 102 GLO R7 ..CHECK IF ALL BYTES only. Loadirg a 38 (SKP instruction) in
55 344F 103 BNZ XTBYT ..SHIFTED. location 5F (line 111) will enable both
57 98 104 GHI R8 ..PVT BIT 0 of 8TH
58 76 105 SHRC ..BYT ON BIT 7 OF shift and roll routines. Loading 30 61
59 5A 106 STR RA ..1ST BYT ON LINE. (BR ROLL) in locations 3C and 3D
5A 19 107 INC R9 ..R9mBYTE 0 NXT LINE.
5B 26 108 DEC R6 (line 82) wi'I enable only the roll rou-
5C 86 109 GLO R6 ..CHECK IF 16 LINES tine.
5D 3A45 110 BNZ NXTLNE ..SHIFTED.
5F 3033 111 BR SPREAD ..SKP 38 ROLL AND SHIFT. After loading and running the pro-
61 84 112 ROLL.GLO R4 ..INCREMENT R4 ONE LINE gram, animation of the display will be-
62 FC08 113 ADI 8 ..ROLL SCREEN UP.
64 A4 114 PLO R4
gin after any nonzero byte is loaded
65 94 115 GHI R4 ..CHANGE I.NNO 116 TO via the INPUT switches and operation
66 F800 116 LDI 00 ..ADCI 0 7C00 IF MORE
68 B4 117 PHI R4 ..THAN 256 BYTES.
of the INPLT pushbutton. By varying
69 3233 118 BZ SFREAD the INPUT bit pattern, you can control
6B 84 119 GLO R4 the speed of the animation.
6C 84 120 PHI R4
6D 3033 121 BR SPREAD If you have never seen a stack in
6F 00 122 DC #00 "motion" when a program is running,
123 .ENTER IMAGE TO BE SHIFTED IN LOCATIONS
124 .X'78' - x'F7'. take a look at displayed location 13.
125 END Then vary the speed.

44 POPULAR ELECTRONICS
 Ist 2nd
BYTE
-
BYTE
is restored to its original value so that it
Ist 2nd 3rd 4th remains pointing at the same eight
DIGIT DIGIT DIGIT DIGIT
bytes.
II 6 5 4 0
MUM mou
6 4 0
TABLE 7 3 2 1
7 5 3 2 1

^-M(0050) The E2 20 AO instructions at M(O02O),

-M (0058)
M(0060)
M(0068)
M(0070)

M ( 0050) 0
Ill
I

7
I I
II
I

f
0
MEMO

B
I I I
I
I

D
0
1111
I
ï I I

E
I 0
la I M(0023), and M(0026) are used to occu-
py six machine cycles between the DMA
requests and to restore RO to its initial
value before incrementing it by eight
during the eight-byte DMA request. The
20 instruction decrements R0.1 back to
-M(0058) 0 I 0 0 I 0 I 0 0 I 0 I 0 0 0 0 its initial value if a 256 -byte page bound-
A 5 0 ary was crossed during the preceding
Fig. 3. Diagram showing how to create your own display. eight DMA cycles.
This one is for parts of five lines of Spaceship Program. After the first group of eight bytes has
been displayed for four raster line times,
quire three cycles for each execution. display spot is four raster lines high, RO is permitted to advance to the next
These are used only to provide the delay which means that each eight -byte dis- group of eight bytes to be displayed.
required between the beginning of the play row must be repeated four times. This process is continued until 32
interrupt routine and the first eight -byte With the interrupt routine, RO is initially groups of eight bytes each (256 total)
DMA request generated by the 1861 dis- set to M(00O0), which means that the have been displayed. At this time, the
play circuits. first DMA request causes the eight bytes circuits in the 1861 chip cause line
Each of the eight display refresh bytes from M(0000) to M(0007) to be fetched EF1 =1 (at pin 9) and the interrupt rou-
requested by the 1861 is internally con- and displayed. The time of each raster tine terminates.
verted to a bit serial form and used to line is exactly 14 machine cycles to per-
provide the luminance (brightness) mit the transfer of eight bytes (eight cy- Other Considerations. The raster
pulses that come out of the 1861 at pin cles) plus the execution of three two - refresh involves the display of 32 groups
7. The actual raster display consists of cycle instructions during each raster line of eight bytes, and each row of eight
262 horizontal lines for each frame, and time. Following the eight DMA cycles re- bytes is repeated on four raster line
there are 60 frames per second. Each quired to refresh the first eight bytes, RO scans. This means that the display re-
fresh ties up the 1802 µP for slightly
more than 128 raster lines (32 x 4).
Since there are 262 raster lines per
1 thru 23 frame, the µP spends about 50% of its
STACK time performing the display- refresh
INTERRUPT 34 thru 64
function.
AND MAIN- PROVIDES
LINE REGS TIMING. Since the 1802 and 1861 clocks must
INCREMENTS remain synchronized, none of the three -
R5. LOADS
RO WITH cycle instructions described in the
REFRESH 1802's user's manual should be used in
65,66 ADDRESS
programs that run concurrently with this
FROM Rd.
display. The only exception is the use of
the C4 instruction in the interrupt rou-
tine.
32,33 The sample program given in Table I
RETURNS
was designed to run in expanded -mem-
TO ory systems as well as in the basic 256 -
MAIN LINE
byte Elf. In the expanded system, just
change the bytes at M(0O19) and
M(O01C) so that RO initially points to any
256 -byte segment of the memory you
INPUT SWITCHES wish to display on the raster. You can
READ 76, ANIMATION
INPUT 77 write any other main program to run con-
SWITCHES SPEED
CONTROL currently with this interrupt routine.
The 1861 chip can also be used to
display any number of memory bytes
from eight to 1024 by rewriting the inter-
rupt routine. For example, change the
byte at M(O024) from 20 to 80, and you
will see 512 bytes displayed on the CRT
83 thru 110 NO 112 thru 121 screen as 64 spots horizontally by 64
SHIFT 16 spots vertically. If you have only 256
LINES YES
RIGHT bytes of memory in your system, you will
CIRCULAR. see the same 256 bytes repeated twice
on the screen. When displaying 512
J bytes, each spot represents half the

JULY 1977 45
height of those displayed when 256 Remove the crystal from the Elf and 32 boxes deep, assuming a 256 -byte
bytes are displayed. wire the Fig. 2B frequency divider to pin memory. Bear in mind that the operating
One of the main advantages of map- 1 of the 180211P. Then interconnect the program given in Table occupies the I

ping main memory directly into the moni- two boards exactly as shown in Fig. 2A top eight lines. Since the program ends
tor or TV raster is the ability to manipu- anc B, including the power lines. Jack J1 at memory location M(003B), load 00
late the display using the normal instruc- can be mounted on a small metal brack- into memory location M(003F) to corn -
tion set. In systems that employ an ex- et and secured to the add -on board with plete that line.
ternal frame buffer for refresh, special- No. 4 machine hardware. Also, mount Now, to display the spacecraft shown
ized instructions are required to change R1 and R2 on the add -on board via in the lead photo, load the programs giv-
buffer contents. The buffer memory also "flea" clips because they may have to en in Tables and II in that order, start-
I

costs more money. With the refresh be changed for different -value resistors ing the Table II program at memory loca-
buffer approach toward animation, you to suit the modulation requirements of tion M(0040). Reset and switch to RUN.
must store two picture patterns in mem- the particular monitor you are using. If you wish to create your own display,

ory and alternately transfer them to the Fig. 3 illustrates how to arrive at the cor-
buffer memory. Using the Pixie graphics Sample Display Program. To test rect hex digits. (In this case, the exam-
display described here, you store the the Pixie, load the program given in Ta- ple used is for a small area of the pro-
same two -picture patterns in memory ble I, starting at location M(0000). When gram in Table II.) Use graph paper to
but you need only change the initial val- this program is run, a random spot pat- `draw" your picture, shading in the
ue of RO to alternately display them. Not tern should be displayed on- screen. At "spots" you want to be white on the CRT
only do you save the cost of a refresh this time, you may have to alter the val- screen. Then transfer the line bit pattern
buffer, you can greatly simplify the pro- ues of R1 and R2 to produce a tight sync into the eight hex bytes per line as
gramming. lock and the desired modulation level of shown in Fig. 3.
the spots. These are only level- adjust
Construction. The Pixie circuit resistors and play no role in the actual Conclusion. The Pixie system de-
can be mounted on the original Elf board sync or video production. The displayed scribed here adds video graphics to your
by relocating the crystal and two capaci- pattern represents whatever is stored in Elf microcomputer at very low cost. So
tors to the center of the board. Now, the the Elf's memory. The top eight rows far, we have described how the Pixie
1861 IC goes on the upper left of the represent the program given in Table I. system can be used to put simple, sta-
board, the resistors on the bottom of the You can familiarize yourself with the tionary images on- screen. Accompany-
board, and the output jack on the rear new graphics ability of your computer if ing this article is a program that will put
apron of the chassis. you visualize a grid of 64 boxes wide by the graphics in motion.

Electronic "Bell" for a TVT -II

Lets you know when you are near the end
of a line on a TV typewriter.

BY DENNIS J. DEUTSCH

Here is an add -on circuit for the cor n- Once the character is counted, the re- The one-shot triggers a 555 timer used
puter hobbyist that will give his set- sulting pulse turns on the 74121 one - as a tone generator to drive a small 8-
up the effect of a bell ringing near the shot for a short period of time. The tim- ohm speaker. To alter the tone, change
end of a line as it does on a typewriter. ing values of the one -shot can be altered the value of the capacitor between pin 6
The circuit, as shown in the diagram, is by changing the circuit's time constant. of the 555 and ground. O
fer use with the Southwest Technical
Products CT -1024 TVT -II terminal. +5V
The CT -1024 produces 32 characters
per line, for which access is required to 33K
SPKR
bits 1, 2, 4, 8, and 16 on the CT -1024. CT -1024
MAIN BOARD .I

/1a
51K
These are located at IC35 and IC42. IC42,PIN 15
BIT 16
10yF
The circuit as shown is set up to pro- BIT 8 1 8
'PIN 7
7 22K
BIT 2 5
duce the tone on character 27. (Bit 4 is PIN 2
4
la
e 4 6
inverted in the 7404 IC so that it is BIT! 7430 74121 555
IC35 PIN 3
"NOT'ed ".) The character number trap +5v
2T
7
consists of an 8 -input NAND gate in the
7430 and the single inverter (which can BIT
' PIN 6
4 404
4
12
N
7 1

jsF .00
be a single transistor if desired). If you 7 yF
want to stay at character 27, eliminate
the inverter and bit 4.
46 POPULAR ELECTRONICS
 : : :: ::::x: :sx :s :xxs :i : : : :s : : *z
s
s
* BUILD THIS TUT -6
2
T
*
*
*
YOUR SOFTWARE CONTROL CAN
INCLUDE INTERLACE, SCROLLING
& A FULL PERFORMANCE CURSOR.
Build the TVT"G:
* UP TO 4096 SHARP CHARACTERS
*
*
ON THE SCREEN IN LESS THAN
THREE MEGAHERTZ TU BANDWIDTH A Low -Cost
DIRECT VIDEO
PART I
DISPLAY
$35 microcomputer "add -on" provides:
User-selectable line lengths
Scrolling
Up to 4k on- screen
characters with only
3 -MHz bandwidth

BY DON LANCASTER
The TVT-6
connected
to a KIM -1.

ADDRESS 02
Er hanks to some software tricks, a
CLOCK

simple and low -cost add -on circuit,

CS TV
and a new way to speed up a micro- OUTPUT
(J2)
processor, you can now build a video in-
terface for your microcomputer for an in-
NEW
vestment of only $20 to $35. The TVT -6 UPSTREAM
TAP-
video system described here permits the
choice of virtually any format including
16/32 (16 lines of 32 characters), 16/64, DECODE
ENABLE
or 32/64. It also features full editing ca- CS SOURCE
H
pability and full -performance cursor. AI5 TIMING SYNC
GATING VIDEO
In spite of its simplicity (10 low -cost AI4 IC2,IC6 1 OUTPUT
013 (JI)
IC's), the circuit employs a new ap- V V

proach to video processing that permits

AI2
All
TIMING
-pr-
V POSITION
SYNC

up to 4000 characters to be displayed RI4

on- screen within a 3 -MHz bandwidth. Al-

though the TVT -6 was designed for the AS
A4
6502 microprocessor based KIM -1, soft- R/W A3
SCA
PR
ICl (6502 CODING SHOWN)
ware can be used to easily map into the A2
0 -30 LOY AO
JOLT, EBKA, or Ohio Scientific mi- AI RTS 60

crocomputers. In addition, the TVT -6

can be adapted to other microproces- DATA BUS
T VT-6
sors, including the popular 6800, 8080, )
KIM -I
OR OTHER
and Z80. It is easiest to use with 16- MICROPROCESSOR SYSTEM

address -line systems that operate on a Fig. 1. TVT -6 block diagram

single 5 -volt supply and 1 -µs cycle time. and truth table for the PROM.
JULY 1977 47
 GND
I
GND
GND
2 GND
PIN 7 OF 1C2- IC6,IC9,ICIO
3 NC PIN 8 OF ICI, IC8
PIN 10 OF IC7
SPARES4 NC
5 NC

I-MHz CLOCK 6 VCL-P.FIG4 AO

7 VD7 +5V
8 VD6 NC 0 24 10 12 6 15
22 16
9 VD5
DATA 21 13
FROM :10 VD4 FIG4OE
DISPLAY 20 5 14
RI3
II VD3 IC7 IC8
MEMORY 19 6 4.7 K
12 VD2 2513 74165 -AMMAN- +5.
13

14
VDI

VD0
18

17
7 4
y C6
33pF
4 15 16 2
IILOAD FIG4 FO
CLOCK
O
= TEST POINT
GND GROUND
N D5
1N4148
FIG4

RV . RAW VIDEO (ENHANCED)

CV COMPOSITE VIDEO R19
VR VERTICAL RATE 4.7K
HR HORIZONTAL RATE
CURSOR

NO YES

13

12

DISPLAY MEMORY 15 CSI

CS 16 CSO
5

--
4
DECODE ENABLE 17 DEN 8
13

9 * 10

C3
.IyF R9
2 2.2M

R8
9 47K
18 All 10
Fig. 2. Parallel outputs
ADDRESS
LINES IS Al2 ile=4011 (IC5) froln character generator
20 A13
*=74LS08 (IC6) IC7 are converted into
+5V
serial data in 1C8.
FIG3O Parts of IC5 and 106
HR

for 77 gating circuits.

FIG3OC

Other systems will require software and

microprogramming translation for their
particular machine languages. 2 FIG4
In this first of a two -part article, we will ©
cover the hardware and construction de-
tails for the NT -6. Next month, we will FIG4
cover debugging, some useful software 21 514
LENGTH
for the system, and provide instructions 22 A15 5V
32 14
on how to couple the TVT -6 to other mi- ADDRESS 23 AS
croprocessors. LINES '24 A4
13

(0,6-10` 12 ICI
NOT USED) 25 A3 5610
26 A2
Circuit Operation. A block diagram
27 AI
10

of the TVT -6, as used with the KIM -1 7 5 4 3 2

system, is shown in Fig. 1. The complete ,28 DB7

29 DB6
schematic diagram of the video system 30 DB5
is shown in Figs. 2 through 4. 31 DB4
DATA.
As shown in Fig. 1, bits 4 through 6 BUS 32 DB3
from the "upstream tap" on the KIM dis- 33 DB2
34 DBI
play memory drive character generator
35 060
IC7 whose blanking and formatting are +5V
helped along by the AND gates in IC6.
The cursor bit (bit 7) is stripped off the
+5V,.2Á 36 +5V
CII!'r
.1551
1
.IY
Cl2
1
PIN 14 OF
PIN 16 OF
PIN 24 OF
IC2 -IC6, IC9, IC10
ICI, IC8
IC7
upstream tap and routed to cursor blink-
.151
er IC5, which introduces a blinking cur-
sor into the character generator's enable
input. Fig. 3. New SCAN instruction uses PROM IC1, which
The parallel outputs from IC7 go to also has the line length option in its circuit.
48 POPULAR ELECTRONICS
 +5V

RI
47011 J2
01
2N4402 TV
R2 OUTPUT
R7 IGK
FIG 9
2
8 22011 14 10

-
0 R5
22K 12
DI
-
C2
120pF? 8 CI
.OIpF D2
IN4148 (3)
3 3
ICIO
R6 4066 2 D3
22K 6 CV JI
VIDEO
4 OUTPUT
7
R4 R3

1
2.2K 22011
R18
2.2K 13 5
C9
330pF
RV

-
)1 C7
.01pF
FIG LOAD
2 R15
3I I/2
il 100K
FIG
2 o CLOCK
C4
IC3
4013
H
POS'N

+5V CIO
D4 240
IN4148 VR pF
RI6 0
2.2K
1/2
1C3 R14
12 IOOK
RI7
2.2K V
*= IC9,74LS32 P0S'N
*=IC4,74LSO4

FIG2 FIG3OI ®FIGS

C8
.047pFT
i
Fig. 4. Video combiner (IC10), offset generator (Q1) and sync delay circuits
deliver video to TV. Gated clock (IC4) controls parallel -to- serial converter.
C 1, C7- 0.01 -).F
Mylar capacitor PARTS LIST RII -100 ohms
C2- 120-pF polystyrene capacitor R12- IOOOohms
C3, C 11, C12, C 13-1). -µF Mylar capacitor
I
R 4,R I5- 100,(xx) -ohm pc -type (upright) po-
I

C4- I50-pF polystyrene capacitor IC8-74165 PISO shift register tentiometer

C5-2200-pF polystyrene or Mylar capacitor 1C9- 74LS32 quad OR gate IC Misc. -Sockets for IC's (seven 14 -pin, two
C6 -33 -pF polystyrene capacitor IC 10-4066 quad analog switch IC 16 -pin, one 24-pin); 36- contact edge con-
C8- 1).047 -µF Mylar capacitor J I . J2 -Pc -mount phono jack (Molex No. nector with 0.156" centers (Amphenol 225
C9- 330-pF polystyrene capacitor I5 -24 -2181 or similar) or similar); solid hook -up wire for jumpers;
C10-240-pF polystyrene capacitor QI- 2N4402 or MPS6523 (Motorola) transis- insulated sleeving; test -point terminals (5);
DI through D5- 1N4148 silicon diode tor solder; etc.
ICI IM5610 32 x 8 PROM (or similar) The following resistors are 1/4 watt, 10% toler-
1C2- 74LS00 quad tri -state NAND gate IC ance: Note: The following items are available from
IC3 -013 dual -D flip -flop IC RI, R10-470 ohms PAIA Electronics, Box 14359, Oklahoma
IC4- 74LS04 hex inverter IC R2- 10,000 ohms City, OK 73114: No. PVI -1PC printed cir-
105 -401 quad NAND gate IC
I
R3,R7 220 ohms cuit board for $5.95; complete kit of all
ICÔ- 74LS08 quad AND gate IC R4,R 16,R l 7,R 18 -2200 ohms parts, No. PVI -IK, for $34.95 (specify
1C7-2513 character generator (must be sin- R5,R6- 22,000 ohms blank or KIM -1 programmed ICI); KIM -1
gle- supply type, such as General Instru- RB,R 13,R 19 -47(x) ohms coded cassette, with programs, No. PVI -
ments No. RO-3 -2513) R9-2.2 megohms CC, for $5.00. All prices postpaid.
I

shift register 1C8, where they are con- The serial video from 1C8 goes to the The vertical and horizontal timing sig-
verted into a serial video signal. The TV Bandwidth Compensator in 1C9, nals from IC2 in the gating circuit are de-
clock and load commands for 1C8 come which predistorts the video by delaying layed by IC3. The display positioning
from gated oscillator IC4, which derives the video output and OR'ing it against it- can be varied by potentiometers R14
its signals from the microcomputer's self. This widens the vertical portions of and R15. The vertical and horizontal
clock. It is important that the correct all characters to generate clean and sync signals are combined with the en-
clock phase be selected to permit the crisp characters that require minimum hanced video from IC9 into video com-
loading of IC8 to occur when the output bandwidth. The amount of widening is biner IC10. The output from IC10, avail-
of the character generator is valid and determined by C2 (Fig. 4). The optimum able at J1, is composite video, with the
settled. This is phase 2 in the KIM-1. (If value of C2 is obtained when the gener- sync tips at ground, black at 0.4 volt, and
you are using a different ILP based com- ated M or W in the video display just white at 1.6 volts. This output can be
puter, check this detail.) barely closes. used to drive conventional video moni-
JULY 1977
49
tors and converted TV receivers. The
video output from ICIO is also fed to 01,
which is offset to deliver a +4 -volt output
for the white level. This output, available
at J2, can be connected directly to the
first video amplifier of most transformer -
powered solid -state TV receivers (see
box for details) without requiring biasing,
coupling, or translation circuits.
Two options are provided with the
TVT -6, both of which are jumper select-
ed The LENGTH option allows a choice
of either 32 or 64 characters /line. The
cuasoR option gives the choice of either
no cursor or allows the cursor to be dis-
played under software control.

Construction. The actual -size etch-

ing and drilling guide for the printed cir-
cuit board used in the TVT -6 is shown in
Fig. 5, along with the component- instal-
lation diagram. Start assembly by install-
ing and soldering into place the 21 jump-
ers and test points. (Note that insulated
sleeving must be used on two of the long
jumpers.) Install the IC sockets, resis-
tors, capacitors, diodes, jacks, and posi-
tion controls R14 and R15. Do not install
the IC's at this time. The correct IC in-
stallation sequence and the waveforms
to be observed will be discussed in Part
2 next month.

Computer Interface. Detailed in Ta-

ble I are the requirements of each of the
edge connector contacts on the TVT -6
and how to use each contact. Table I
also contains the KIM -1 interface con-
nection instructions. The interface con-
sists of adding a new connector and
making some add -on connections. One
H POS V
circuit board trace is cut on the KIM -1's ..

pc board to permit an optional change- OGr°D °

-C2-
,,
t 1 I

R4 I R5 I -R15 RIc- RG

0
I RI C.
over switch (or jumper) to be added to Rs R2 Rb . C9 t-3 I
O
1 1

..
Y

the microcomputers. This permits KIM -1 Tv

R18

TVT-6
F

to be used with or without the TVT-6. `v I 74L532

01c10 0l
General Operation. Since most of
12
-s- ^IOW- 1cs

C3 R9
1 - I C11 1
-1111r' IC

J
today's TVT circuits are used with a mi- °

--
1
1

croprocessor or microcomputer, it is 4 W
n I
best to do as much of the display control VID CURSCiR 1C7
..}4-
J

R17
324-JLENGTH j D4
as possible with the microprocessor and C13 I YES NO
some software. What may not be obvi-
ous is that almost all of the timing in the
system can also be done using the mi-
J
1
/1 -- J
-R16-
7^
1

R8
1 J
IC6
I(."111r.
1-
"-Wr",
IC4
-RlI-
-C
croprocessor. All this takes is a few doz- C? ° rC2
er words of code. o
The four key secrets of operation for
5610
0
e s
253 74 L 50 4
-C4-
the TVT -6 are: 36
> o r
t-+ 7 H
HR
O-J Z p ..o 0
1. Carefully choose how the address m m m m m r, Q Q n V V V V Z Z
lines are defined for TVT operation.
m
Q Q c 0 o Q Q O
co co
d< C't
d d d d d Q Q Q > > > `> > > > > Z z z 0 0

2. Add a new instruction, which we

call SCAN, to rapidly address 32 or 64 se-
quential memory locations. Fig. 5. Actual -size foil pattern (top) and component installation
3. Permanently connect an upstream (below). Use sockets for all IC's. Edge connectors go to KIM-I.
50 POPULAR ELECTRONICS
 TABLE I
TVT -6 PINOUT AND KIM -1 INTERFACE

TVT-6 A4, R (A13) 20

CONTACT NAME REMARKS A3, S (A14) 21
1,2 GND Heavy wire to expansion contact 22 or simi- A2, T (A15) 22
lar point in KIM -1 Al F (A5) 23
3, 4, 5 NC Spares E (A4) 24
6 VCL 1 -MHz clock from expansion contact U(02). D (A3) 25
(In other systems clock phase must be se- C (A2) 26
lected so that load pulse arrives when CG is B (A1) 27
valid.) 28, 29, 30, DB7, µP data bus; tri -state active high from IC1
7,8,9,10, VD7, Data output from memory display; drives 31,32,33, DB6, during active scan, not used at other times.
11,12,13, VD6, character generator. For KIM -1 to display 34, 35 DB5, Connections to KIM -1 expansion:
14 VD5, any part of pages 00 through 03, connec- DB4, KIM -1 contact: to TVT -6 contact:
VD4, tions must be made as follows: DB3, 8 (BD7) 28
VD3, TVT -6 contact: to pin 12 of KIM -1 IC: DB2, 9 (DB6) 29
VD2, 7 U5 DB1, 10 (DB5) 30
VD1, 8 U6 DB4) 11 (BD4) 31
VDß 9 U7 12 (DB3) 32
10 U8 13 DB2) 33
11 U9 14 (DBI) 34
12 U10 15 (DB4)) 35
13 U11 36 +5V Regulated +5 -volt (200 -mA) power bus;
14 U12 should be heavy wire. From KIM -1 expan-
15 CSI Display memory chip select from µP; nega- sion contact 21 or similar point to contact 36
tive logic OR combined with TVT -6 chip se- in TVT -6.
lect. From pin 1 of U4 on KIM -1.
16 CSO Display memory chip select source; enables Note: KIM -1 conversion consists of breaking one foil trace and
display memory when either TVT -6 is active adding a new 36 -pin socket (Amphenol 127 or similar). Connec-
or contact 15 is low. Goes to pin 13 of U5 tion to be broken originates as KO (pin 1 of U4). Routing of Kßthat
through U12 in KIM -1 when displaying any goes to memory chip select pin 13 of U5 through U12 should be
part of pages 00 through 03. Existing K4) broken. Other K4connections, such as that to pin 1 of U16 should
connection in KIM -1 must be broken. remain intact. Any external ground connections to Application
17 DEN Decode enable; goes low when µP is oper- connector contact K (decode -enable) must be removed. All wiring
ated in normal mode, high when TVT -6 is should be made with a wiring pencil.
doing an active scan. Goes to KIM -1 Ap- When KIM -1 is used without displaying video, it will behave nor-
plications contact K. Any external ground on mally and transparently as long as TVT -6 is plugged in and ad-
applications contact K should be removed. dresses 8000 through DFFF are not used. To restore KIM -1 oper-
18,19,20, Al1, Address inputs from µC, positive true. Ád- ation with TVT -6 out of socket, or to use available addresses for
21,22,23, Al2, dresses A,4), A6 through A10 not sent to other programs, jumper pin 15 to pin 16 and separately jumper pin
24, 25, 26, A13, TVT -6. Connections to KIM -1 expansion: 1 to pin 17 in the KIM -1. Note that this jumpering
is to be done only
27 A14, KIM -1 contact: to TVT -6 contact: when TVT -6 is out of its connector. you wish, a dpdt changeover I

A15, N (Al 1) 18 switch can be added to perform the jumpering. Switch positions
A5, P (Al2) 19 should be changed only when power is off.

memory tap to the character generator V. LOCATION H. LOCATION

SYNC ROW PAGE (LINE) (CHARACTER POSITION)
and display circuit.
4. Create special software that will IHSIVS LIJ 0 I I IV8IV4IV2I VI IH16IH8IH4IH2I I]
allow TVT -6 scanning. I UPPER WORD I LOWER WORD
I
I
All 16 address lines are used, as- A815 ABS AB7 ABS
(A) ADDRESS BUS: 32 CHARACTERS /LINE, 16 -LINE SYSTEM
signed as shown in Fig. 6A for a 32 -cha-
racter /line system or as shown in Fig. SYNC ROW PAGE V. LOCATION H. LOCATION
6B for a 64- character /line system. Ad-
L4 L2
i JV 81 V4 1V2
dress A15 is the horizontal sync pulse I HS I VS I I I LI I
j VI 1H32] H161118 I H4 I H2 I HII
and the key to jumping to the new SCAN I

AB15
I
ABS AB7
I I

ABO
instruction. This pulse is followed in de- (B) ADDRESS BUS:64 CHARACTERS /LINE, 16 -LINE SYSTEM
scending address order by the vertical CURSOR ASCII CHARACTER ASCII CHARACTER KEYPRESSED
sync (A14) and three lines (L4, L2, L1)
that produce the "what row of dots do
/11=11=111.,
IKPI
we want ?" information for the character 1 7 16 15 14 13 12 I I I 01716I5141-3121]
D87 DB0 PA7
generator. The lower address lines are PA0 IRO
(C) DATA BUS (D) KEYBOARD INPUT
used to select a page of display memory
and to select the character that goes into
any particular horizontal and vertical lo- Fig. 6. Bus definitions as used with the TVT -6.
cation on the display. All 16 address lines are used as described in. text.
JULY 1977
51
 interrupt and reset vectors on the KIM -1
DIRECT -VIDEO INPUT CONVERSION so that the operating system will work
0201 compatibly and properly with the new
Ist VIDEO AMP
BREAK SCAN instruction.

- o
CONNECTION\
FROM TPI2 \\ There are many possible codings for
4V
VIDEO the SCAN program with the limitation that
DETECTOR
the last address is a return -to- subroutine
(RTS) instruction. The obvious choice of
GROUND
AT VIDEO
NOP or EA runs at only half speed and
NEW
RG -174
AMP ENO
ONLY
can't be used. Of the three dozen in-
SHIELDED structions that operate at full speed, the
COAX
choice of LDY is the one that does not
Adding a TVT -6 direct -video input to a disturb the accumulator or its flags. This
small- screen solid -state TV receiver re- 'EARPHONE JACK
(REMOVE OLD adds flexibility to other programs. The Y
quires only two short lengths of shielded CONNECTIONS) register can be viewed as a write -only
coaxial cable, as illustrated in the sche- memory in the SCAN software and we
matic. (Important Note: Do not use a hot -
can think of the whole SCAN instruction
chassis TV receiver! Make absolutely cer- The earphone jack in the circuit provides
as a group of double -speed fetch -but-
:ain that the TV receiver you use is trans- automatic changeover from normal receiv-
=ormer powered from the ac line.) The
don't- execute instructions. Theoretical-
er performance to video access. Correct
conversion circuit shown here is for the bias is provided by TV output of the TVT -6. ly, a 64 -word PROM would be required
Sears No. 562 -50260500 (Sams Photo - As an option, you can defeat the sound for a 64- character line, but this can be
'act No. 1565 -1). Other TV receivers can trap in the Sears TV receiver by lifting one overcome by ignoring address Aß and
be modified in a similar manner. end of capacitor C201. changing the PROM's address every
second cycle of the machine.

The data within the machine (see Fig. To use the SCAN instruction, jump to a Upstream Tap. The SCAN instruction
6C) uses the lowest seven bits as ASCII subroutine whose starting address is will sequentially address 32 or 64 mem-
character storage. This is arranged by within the 8000 to DFFF range. For ex- ory slots per horizontal scan line at a
putting the least- significant ASCII char- ample, if you call JRS 8200, the SCAN in- rate of one -per -clock cycle (1 µs). These
acter bit in the least- significant data slot, struction will deliver a horizontal sync addresses are presented to the entire
and so on up through the more signifi- pulse and initiate operation on the top memory in the computer, including the
cant bits. The eighth data bit (DB7) is re- row of characters, starting with the first memory to be displayed. However, dur-
served for a cursor. If DB7 is a zero, a character on page 2. After a selected 32 ing the display times, the SCAN instruc-
character is displayed, while if it is a one,
a cursor box is optionally displayed.
NEW SCAN ENABLE INPUT BIT 7 TO
The existing KIM -1 keypad can be -FROM 8000 -DFFF DECODER TVT-6 CURSOR
IN TVT -6 (IC5)
used as an ASCII keyboard for many ap-
plications, particularly for setup and de-
bugging. If you wish to add an external BITS 0 -6
TO TVT -6
NEW NEGATIVE -LOGIC
ASCII keyboard and encoder, connect it OR GATE NEW CHAR. GEN.
(IC7)
"UPSTREAM.
to the KIM -1's parallel interface A, fol- CONNECTIONS 3US
DFIVERS
lowing the assignments shown in Fig. (UI3-U14)
MEMORY
6D. The seven ASCII bits go to the sev- TO BE COMPUTER
DISPLAYED OUT DATA
en low -order data lines, while PA7 is LJ
(U5 -U12) BUS
CS R/W
hard wired for a zero. The keypress, or I"
BREAK
strobe, signal from the keyboard must EXISTING
CONNECTION READ /WRITE
pull the IRO (interrupt request line) to
BUS
ground for 10 µs to enter a character or ACCESS
LOGIC
machine command.
The truth table for PROM ICI is
shown in Fig. 1. This truth table stores DECODE
ENABLE
the SCAN instruction activated by
, (K0)
addresses 8000 through DFFF. When Fig. 7. Adding the upstream tap to the memory to be displayed.
/CT is enabled, it causes the micro -
prccessor's program counter to appear or 64 characters, the SCAN instruction tion and its PROM have control of the
on the address lines for 32 or 64 con- automatically jumps back to the main data bus so that the display memory (or
secutive scans that advance one count program. anything else) cannot output information
per microsecond. This automatically and The SCAN instruction can be viewed to the data bus.
sequentially addresses the display as a "portable subroutine" because it The upstream tap is added as shown
memory and produces exactly the data readily moves around to automatically in Fig. 7. This tap is always outputting in-
needed for a horizontal scan of TVT output the correct page and character formation to the character generator in
characters. The scan instruction runs at generator's row information, starting the TVT -6. The output information is
least twice as fast as the microprocessor with an easily computed JSR address. present even (and especially) when the
normally moves, which is the key to TVT Addresses above DFFF will not activate display memory data bus drivers have
timing with a microprocessor. the SCAN instruction. This includes the been inactive.

52 POPULAR ELECTRONICS
 From: Nagasakiradio
Nagasaki Japan
JOS, JOR, JOU, JDB (Nagasaki Radio)
Harry acknowledges reception with informal
/\
To:Nr. L. Helms, Jr. OCT 20th 1975

osi Tnz for your O0L repor

Your de Ns 11
firmed!
QSL which lists call signs, power (kW),
frequency (kHz), and operating hours (GMT).
N
BY HARRY L. HELMS, JR.

VO 7
Q

JD 1...FLEME
TAtLE of opERAT10N F10uR oN
C.Iwashita, radio operator

MOH FAEauENC7
of Nagasaki radio

(GPI r)
END THAT
"UTILITY
S13TM 40..4' FREQ. OP3RAT1oN MOOR

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(3"') a If of ,. ,.
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JOS 3 1.401.s
JOR 10 05134
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FUTILITY"
Jou IS 15,937.2
Jot I3 17093.1
JOB 13 17.21s
Jos 223%
JOR
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IF 22.309 DXing CW without knowing Morse code
22.440
U
J31t, l
IC
_ 4.1573

If you're like a lot of SWL's, you're not onto a frequency while waiting for traffic. ). And often you will hear the let-
getting full use of your shortwave re- Marker transmissions often follow this ters "K," "SK," or "AR" sent at the end
ceiver. You DX the international and general format: the tape starts with a se- of a marker. All three are generally used
tropical broadcasting bands for sure, ries of the letter "V" (VVV VVV VVV, to denote the end of the text of the mark-
and you probably eavesdrop on the etc.) or a series of CQs (CQ CQ CQ, er. Thus you're likely to hear a marker
amateurs, broadcast band, and interna- etc.). This is almost certainly followed by running something like this: "VVV VVV
tional radiotelephone circuits from time "DE," which is French for "from ". Next VVV DE WXX WXX WXX QRU? QSX 6
to time. But what about those CW sta- comes the station callsign, usually re- 8 12 MHZ AR." Translated, this means
tions -Morse code. Tune outside the peated three times. Thus, typical marker that station WXX is not busy at the mo-
broadcasting bands and you'll find transmissions read something like this: ment and is asking listening stations if
scads of those dit -dah stations dotting "VVV VVV VW DE WXX WXX WXX" or they have any traffic for WXX, and that
and dashing away around the clock. "CQ CO CO DE WXX WXX WXX." The WXX is listening on the 6, 8, and 12-
Have you ever tried your hand at DXing marker often contains additional items, MHz utility bands for a reply.
these stations? such as the 0-code abbreviations How can one translate those dits and
Prime DX lurks in the CW utility "QRU ?" ( "Do you have anything for dahs into readable letters if one doesn't
bands! Countries such as Iceland, Ber- me ? ") or "QSX" (I am listening on know CW? The secret lies in the fact
muda, Barbados, and the Canal Zone
are missing from many SWL logbooks
because they are extremely difficult to
hear on the broadcasting bands. But PRIME MARITIME CW DX BANDS
these countries and others are active. 4231 -4361 kHz 12689 -13170.5 kHz
They're often heard on the CW utility 6345.5 -6514 kHz 16917.5 -17255 kHz
bands, and they readily verify reports as 8459.5- 8728.5 kHz 22374 -22624.5 kHz
well!
"But I don't know CW," you may pro-
test. If that's all that has prevented you
from DXing the dah -dit stations, relax. CW MARKER ABBREVIATIONS & CODES
For the simple fact of the matter is that VVV General opening for a marker; usually sent in a series of
you don't have to know the code to DX three
and verify CW stations! CQ General call to any station, often used to start marker
DE French for "from," precedes station callsign.
QRU? Do you have any traffic for me?
Markers Make it Easy. There's
QRX Iwill call on the frequency of
nothing magical about DXing CW sta-
QSX I will be listening on the frequency of
tions if you don't know the code. CW sta- QSY Iam changing frequency to
tions offer a ready -made DX aid in the K At end of marker, denotes end of message
marker transmission, which is a repeat- AR Same as K, meaning end of message
ed taped transmission used by a CW SK Station work completed
station to establish contact or to hold
JULY 1977 53
 COMMONLY HEARD The Overseas Telecommunications Commission
SAustralia) has pleasure in confirming your
Your report of ion heard on
8/8/75
F(. oREIGN CW STATIONS kir piiorawof the following transmisvfs
4352 NBA Balboa, Canal Zone SOFttairairy 21AllijIME 1401PTIdari
Ìs -7
'31r
6376 `.'PN Nassau, Bahamas 'C 3
6379 .'0 St. Philip, Barbados
EMMISSICN Al
6383 EAD Madrid, Spain
TRANSMITTER POWER 1 KW
6386 HKC Buenaventura, Colombia
THE OVERSEAS
6393 ZLO Waiouru, New Zealand AERIAL TYPE:.. DELTA MATCHED DIPOLE TELECOMMUNICATIONS
6439 OXZ Lyngby, Denmark COMMISSION (AUSTRALIA)
AERIAL BEARING:.....
6446 OXZ Lyngby, Denmark
6463 HKB Barranquilla, Colombia
- FRá@U&i1CX ..6464 KIiz
u"
0 L a,ÌÌstniáittional body response for
6464 VIS Sydney, Australia telecTivi389ciffrfs services between A t$@gIf8 nd other

'c
6467 JCS Choshi City, Japan counm
tq E ndd bbeCCwween Australia's externNlterna ies and shipping.
thank4t{Cfcilftur report on Its.transoSisst6rt, d conveys
6470 IAR Rome, Italy best vrorshes. - va'

6487 VRT Bermuda ` t Signed for 0.7 C.

6491 PJC Willemstad, Curacao

6491 JOS Nagasaki, Japan The Overseas Telecommunications Commission (Australia) sends this
6512 TFA Reykjavik, Iceland QSL with service, call sign, emission, transmitter power, antenna type,
8472 NMR San Juan, Puerto Rico and frequency as part of the confirmation of one of -ts transmissions.
8479 JCU Choshi City, Japan you'll have to work quickly and accurate- so, turn on your tape recorder, get a
8481 VIS Sydney, Australia
ly. With practice, you'll find that it will pencil and paper. and grab the code ta-
8483 DAN Hamburg, West Germany
only take a couple of minutes, even with- ble that accompanies this article. We are
8511 DAL Hamburg, West Germany
8521 VIS Sydney, Australia
out the aid of a tape recorder. now going to end your utility futility!
8523 JOR Nagasaki, Japan The Morse code is a language of The next thing you are likely to hear
8530 IAR Rome, Italy sound, with only two sounds ':o learn: the after the "V" or "CO" series are the let-
8574 HKC Buenaventura, Colombia dit (a short, staccato sound) and the dah ters "DE," explained earlier. In CW, they
8598 OXZ Lyngby, Denmark (approximately three times as long as make the sounds "dandidit dit," and
8647 JDC Choshi City, Japan the dit and drawn out). Forget all about should be memorized along with "V"
8666 OXZ Lyngby, Denmark dots and dashes -those are relics left and "CQ." The call letters of the station
8666 HKB Barranquilla, Colombia over from the days of landline telegra- are almost invariably next. Concentrate
8666 HKC Buenaventura, Colombia
phy-and also forget any visual code ta- on getting the first letter. As soon as you
8670 IAR Rome, Italy
ble you may have memorized. On radio, hear it, look on our code sound table un-
6682 EAD Madrid, Spain
8686 JCT Choshi City, Japan CW is sound. til you find the letter that matches the
8690 TFA Reykjavik, Iceland Learn to recognize the "V" or "CQ" sound. As an example, suppose that the
8694 PJC Willemstad, Curacao series that open markers by their sound first sound you hear following "DE" is
6710 VPN Nassau, Bahamas in CW. A "V" comes out as "didididah" "didandah." As soon as you hear it, con-
8718 8P0 St. Philip, Barbados and "CO" sounds like "dandidanditdah- centrate on the sound, perhaps by re-
8718 VRT Bermuda dandidah." Memorize these sounds and peating it to yourself -"didandah, didah-
8726 NMR San Juan, Puerto Rico practice them by repeating them to your- dah . . ' -until
. you locate it on our
12709 8P0 St. Philip, Barbados
self or by whistling those sounds. Using code table. In this case, you'll find that
12709 VRT Bermuda
12718 NMR
this technique, you'll be able to recog- "didandah" represents the letter "W."
San Juan, Puerto Rico
12832 DAF Hamburg, West Germany
nize the "V" or "CQ" that indicates that So you'll now have the first letter in the
12943 ZLO Waiouru, New Zealand you're hearing a marker. Listen carefully station's call. Repeat this process with
12952 VIS Sydney, Australia to the transmissions that follow the the next le:ter, and the next, until you
13065 EAD Madrid, Spain opening. Is it repeated over and over? If have the station's complete call sign.
' 3069 TFA Reykjavik, Iceland
1 7170 PJC Willemstad, Curacao

ORCCIPIC.

that a marker is repeated for several

Thank you for your reception report
rrinutes at a time, usually at a code 8
of our signals on
speed considerably below that normally
used, and the message is the same as reported by you on Vail/'!S
each time it is repeated. In fact, you may
find some markers repeated for hours at Mr. Sorry Solos, Jr.

a stretch. Thus, you need persistence

We appreciate your interest.
125 Yost Wog St1'..i

and patience to bag CW DX, not code jeftgAA )( Í Apr! 1Kl11, S.C. 29715

proficiency.
Your task will be greatly simplified if Traffic Supervisor
you have some form of tape recorder,
either reel -to -reel or cassette. If you do, 041' (4-79)

it helps to record several minutes of the

marker. If you don't have a tape record- TRT Telecommunications Corporation acknowledges reception
er, you can still log CW stations, but by confirming the transmitting frequency on the dzy and date.
54 POPULAR ELECTRONICS
 This may sound like a long and tedious
process, and it may be so at first. But af-
ter a little practice you'll be able to copy WHERE TO SEND CW DX RECEPTION REPORTS
the complete text of the marker within KFS, ITT World Communications, Box 56, Half Moon Bay, Calif. 94019
minutes. If you have trouble with the KHK, RCA Global Communications, 223 S. King St., Honolulu, Hawaii 96804
code sounds, try adjusting your receiv- KLB, ITT World Communications, 3620 Old Hiway 99, Marysville, Wash. 98270
er's beat frequency oscillator (BFO) for a KOK, ITT World Communications, 18500 S. Bloomfield Ave., Cerritos, Cal. 90701
different pitch. KPH, RCA Global Communications, 135 Market St., San Francisco, Calif. 94105
WAX, TRT Telecomunications, Box 8876, Fort Lauderdale, Florida 33310
Verifications. WCC, RCA Global Communications, Box 397, North Chatham, Mass. 02650
It's a snap to prove to
WLO, Mobile Marine Radio Inc., Box 743, Mobile, Alabama 33601
the CW utility station that you heard
WMH, Dundalk Marine Terminal, 2700 Broening Highway, Baltimore, Maryland 21222
them. Simply copy the complete text of
WNU, TRT Telecommunications, P. O. Drawer E, Pearl River, Louisiana 70452
the marker transmission and report in WNY, RCA Communications Inc., 60 Broad St., New York, NY 10004
the usual manner. Normally it's a no -no WOE, RCA Communications Inc., 8580 Lawrence Rd., Lake Worth, Florida 33460
under international law to repeat the de- WPA, RCA Global Communications, Box 1328, Port Arthur, Texas 77640
tails of a utility station transmission. For- WSC, RCA Global Communications, Box 34, West Creek, New Jersey 08092
tunately, markers are an exception. In- WSL, ITT World Communications, Mackay Marine Div., Amagansett, New York
clude the date and time in GMT. Avoid
using common reporting codes such as
SINPO and SINFO. Plain English will do
fine. Make particular note of any hum or
frequency shifting of the signal.
Estimate the frequency as best you age receiver not calibrated so accurate-
can. If you are one of those fortunate COMMONLY HEARD ly, estimate the frequency to the best of
SWLs with direct -frequency readout re- AMERICAN CW STATIONS your ability. If you get deeply involved
ceivers, this is no problem. But if you're with CW DXing, you may find an exter-
like most of us and use a general cover- 4247 KPH San Francisco, Calif. nal frequency standard that puts out
4274 KFS Palo Alto, Calif. markers every 100 kHz will be a good in-
4283 KOK Cerritos, Calif. vestment. They often run around $30
4310 WNU Slidell, Louisiana more or less.
4322 WPA Port Arthur, Texas It is always wise to include a prepared
CW CHART BY SOUND 4331 WSC Tuckerton, New Jersey card with your report. Put the station call
4346 WMH Baltimore, Maryland
A didah and location on the card, along with the
4349 KLB Marysville, Wash.
B dahdididit date and time the station was heard. If
6376 WCC Chatham, Mass.
C dahdidahdit you had to estimate the frequency, leave
D dahdidit 6390 WAX Ojus, Florida
6411 KLB Marysville, Wash. a space blank for the station operator to
E dit
F dididahdit 6411 WOE Lantana, Florida include the exact frequency. You might
G dahdahdit 6435 WPA Port Arthur, Texas like to leave some space for the station
H didididit 6463 KOK Cerritos, Calif. operator to make some remarks, along
didit 6477 KPH San Francisco, Calif. with a line for a signature and station
didahdahdah 6495 WNU Slidell, Louisiana
K dahdidah
stamp. Frequently, a station will have its
6502 WSC Tuckerton, New Jersey
L didahdidit own QSL cards or will send a letter, but
6519 WNY New York, New York
M dahdah a prepared card is the best way to en-
8486 WOE Lantana, Florida
N dahdit sure a reply.
O dahdahdah 8502 WMH Baltimore, Maryland
8514 WSL Amagansett, New York Included here is a list of the major CW
P didahdahdit
Q dahdahdidah 8526 WAX Ojus, Florida utility bands. They're mainly used by
R didahdit 8542 KHK Honolulu, Hawaii coastal stations. Also presented is a list
S dididit 8558 KFS Palo Alto, Calif. of commonly heard stations and the fre-
T dah 8570 WNU Slidell, Louisiana quencies on which they have been ac-
U dididah 8582 KLB Marysville, Wash. tive of late. More complete listings of
V didididah
8586 WCC Chatham, Mass. CW stations can be obtained from Han-
W didahdah
8590 KOK Cerritos, Calif.
X dahdididah dler Enterprises, Box 253, Deerfield, Illi-
Y dahdidahdah 8610 WSC Tuckerton, New Jersey
nois 60015 and Gilfer Associates, Box
z dahdahdidit 8618 KPH San Francisco, Calif.
239, Park Ridge, NJ 07656. You might
1 didahdahdahdah 8630 WCC Chatham, Mass.
2 dididahdahdah 8642 KPH San Francisco, Calif.
also be interested in joining a radio club
3 didididahdah 8658 KLB Marysville, Wash. that features coverage of CW DX. Three
4 dididididah 8658 WSL Amagansett, New York such clubs are American SWL Club,
5 dididididit 16182 Ballad Lane, Huntington Beach,
8686 WMH Baltimore, Maryland
6 dahdidididit
7 dahdahdididit 8714 WLO Mobile, Alabama Calif., 92649; Newark News Radio Club,
8 dahdahdahdidit 12808 KPH San Francisco, Calif. Box 539, Newark, New Jersey, 07101;
9 dahdahdahdahdit 12844 KFS Palo Alto, Calif. and SPEEDX, Box E, Elsinore, Calif.,
0 dahdahdahdahdah 12925 WCC Chatham, Mass. 92330. Enclose a self- addressed
? dididahdahdidit 12993 KOK Cerritos, Calif. stamped envelope with your requests
dahdididahdit 12997 WSL Amagansett, New York
didahdidahdidah for information to these clubs, and you
might enclose $1 if you want to examine
a sample bulletin.
JULY 1977
55
 How to maintain tape recorders and tapes
in peak condition.
BY CRAIG STARK

APART from inquiries about specific chocolate -colored band that develops
product recommendations, the sub- on the blac< pressure roller is an obvi-
ject of most concern to readers is how to ous warning that housekeeping is in or-
care for their recorders and tapes. der. If the tape you use has a black ox-
In addition to routine household dust- ide, you will have to look more closely to
ing, recorders need two kinds of periodic see the shiny band that appears. In any
cleaning: physical and magnetic. The case, the build -up of flaked -off oxide
tape has yet to be made that does not particles must be removed from all parts
shed some of its oxide particles with ev- in the head assembly and anywhere the
ery playing, and unfortunately these tape contacts the recorder.
tend to accumulate on tape heads and
guides, pressure pads, and the cap- Magnetic Considerations. Though
stan /pressure -roller drive system. If not unseen, residual magnetism induced in
removed, this debris can cause slippage heads, guices, and capstan represents
in the drive mechanism. The resulting an even greater potential danger to your
wow and flutter is heard as inconstancy tape collection, and preventive or thera-
or "graininess" in pitch. In addition, the peutic treatment is indicated at least as
oxide accumulations on the heads often as physical cleaning. Professional
cause momentary "drop- outs" in the sig- studios "degauss" their machines daily
nal and loss of treble response. (every 8 to 20 hours of operating time is
Happily, the solution is as near as a the usual recommended rule of thumb)
bottle of isopropyl or rubbing alcohol and to guard against this insidious force. A
an ordinary cotton -tipped swab. If the magnetizec component anywhere in the
tape you use has a brown surface, the tape path will create some hiss and per-

56 POPULAR ELECTRONICS
manent loss of high- frequency signal net from the kitchen memo board, "to
whether you're recording or simply play- see if it would stick." The magnet didn't, Empire's
ing back a tape.
Fortunately, head demagnetizers are
but the once -around blip did.
To assess the potential dangers, I
Blueprint For
inexpensive accessories available from consulted several experts and found Better Listening
all dealers, and using one properly takes
less than a minute. Start by turning your
recorder off and removing all tapes from
they agreed that most fears about acci-
dental damage from magnetic fields
generated by radar, house wiring, home
- No matter what system
you own, a new Empire
the immediate vicinity. Remove the appliances, power transformers, and -phono cartridge is certain
head covers (you should have done this even loudspeakers -are exaggerated. to improve its performance.
already for the physical cleaning); and, The reasons are two formidable- The advantages of
holding the tape -head degausser at sounding but relatively straightforward Empire are threefold.
arm's length, plug it in, push its "on" but- factors: "tape coercivity" and "the in- One, your records will
ton (if it has one), and bring it in close verse square law." Coercivity is simply last longer. Unlike other
proximity to each of the surfaces that an index of the amount of magnetic en- magnetic cartridges,
contact the flowing tape. Then, with the ergy necessary to erase a tape and is Empire's moving iron
demagnetizer still on, withdraw it slowly measured in oersteds (0e). Tapes gen- design allows our diamond
and smoothly. Turn it off when it is at erally have a coercivity in the 280- to stylus to float free of its
arm's length from the machine and the 450 -0e range, but this value is a kind of magnets and coils. This
job is done. Note: to avoid any danger of an average (some oxide particles re- imposes much less weight
scratching the tape heads, it is a good quire more field, some less, for erasure).
on the record surface and
idea to put a piece of plastic tape over The consensus among the experts was:
insures longer record life.
the tip(s) of the degausser. (Because of a good rule for general tape safety is to
Two, you get better
differences in physical design, it is not keep the absolute peak level of stray
possible to get every tape -head demag- fields to less than 10 per cent of the tape
separation. The small,
netizer to the heads of every recorder. coercivity. For ferric -oxide tapes, this
hollow iron armature we
Check with your dealer to make sure amounts to 25 to 30 0e, and for chromi- 'use allows for a tighter fit
there will be no problem.) um- dioxide tapes, 45 Oe. One gentle- in its positioning among
For most audiophiles, lubrication of a man reported measuring a magnetic the poles. So, even the
recorder is best left to a yearly visit to the field of only 10 Oe at the case of an elec- most minute movement is
service technician. Too much is as great tric drill, so it surely would be safe to use accurately reproduced to
a danger as too little! Obviously, though, in the vicinity of most tapes. (In fact, give you the space and
bearings and sliding and rotating sur- home -appliance motors aren't that dif- depth of the original
faces must have lubricants. If you want ferent in principle from those used in recording.
to do the job yourself, follow the manu- tape decks.) However, for really critical Three, Empire uses
facturer's instructions carefully. tapes, it was suggested that external 4 poles, 4 coils, and 3
fields should be kept below about 10 magnets (more than any
Caring for Tape. Tape care is no less and 15 Oe for iron and chrome tapes, re- other cartridge) for better
important. Always keep tapes in their spectively, since high frequencies tend balance and hum rejection.
containers when not in use, and put tape to be more easily erased.
The end result is great
reels on edge -not piled atop one The other factor is a function of dis-
listening. Audition one for
another. recommend the professional
I tance. Even a bulk tape eraser that may
practice of leaving tapes in a played, not
yourself or write for our
generate a powerful 1,000-0e field mea-
a fast-wound condition, for the latter
free brochure, "How To
sured at a distance of /2 inch measures
tends not only to create an unevenly only one fourth that field at one inch, and
Set The Most Out Of Your
wound tape "pack," but also to put inter- one sixteenth at two inches. That's the Records" After you com-
nal stresses on the tape layers that may effect of the inverse square law, and it pare our performance
cause damage. For the same reason, holds, generally, for magnetic record- specifications we think
it's a good idea to play -not rewind -a you'll agree that, for the
tape at least twice a year. Avoid storing
tapes next to a radiator, in the immedi-
ings. Thus, even a few inches of separa-
tion from potentially damaging fields
magnetic latches on cabinets for exam-
- money, you can't do
better than
ate vicinity (within 2 to 3 feet) of strong ple -can prevent signal damage. Empire.
magnetic fields (loudspeakers, motors, You can measure steady -state or
or power transformers in hi -fi equip- "permanent" fields (around a speaker
ment), or in a car trunk during warm cabinet or from magnetized tape heads,
weather. Given proper care, your tapes guides, and capstans) with an inexpen-
should outlast their owner! sive ($6.80) magnetometer from R. B.
Accidental erasure, especially of the Annis, 1101 N. Delaware St., Indianapo-
high frequencies, is something to worry lis, Ind. 46202. Multiply your readings by
about. once ruined a $35 test tape by ten or even a bit more on recorder parts
ENPIFE
I

using a screwdriver, that didn't know

I that touch the tape directly. You'll find
was magnetized, for some head adjust- with speakers that the magnetic "leak- Already your system sounds better.
ments; and a friend once tearfully played age" field varies from model to model Empire Scientific Corp.
for me a master tape on which his five - and, of course, the point on the cabinet :garden City, New York 11530
year -old had momentarily placed a mag- at which it is measured.
CIFxLE NO. INFORMATION
JULY 1977 17 ON FREE CARD
57
An Introduction to gyrator Theory
How inductors can be simulated
using resistors, capacitors, and op amps.
BY BRYAN T. MORRISON

A GYRATOR, believe or not, is an

it gain stage, we can create a circuit which with zero admittance, so R2 is removed
Pt inductor without any turns of wire. appears to the "outside world" as a real from the circuit. At an infinite frequency
Although the theory behind this interest- inductor. To understand how, we will L is an open circuit and R1 is removed
ing circuit has been established for analyze the inductor models (Figs. 1B from the circuit. However, C is a short
some time, only within the past few and 2B) in terms of "port admittance." A circuit and current through it is limited
years have synthesized inductors been port is a point through which energy can only by R2. Between these frequency
used on a wide scale. Before we exam- enter or leave. In the case of an electri- extremes, L will determine the port's
ine the gyrator in detail, let's review cal circuit, it can consist of a pair of ter- admittance, because it is much larger
some basic properties of inductors. minals to which a circuit element is con- than C.
A pure inductance is a circuit element nected. The inductors and their models The port admittance of the air -core
whose opposition to the flow of alternat- in Figs. 1 and 2 are ports, and when a coil at dc is simply the reciprocal of re-
ing current (inductive reactance) vanes voltage source is connected across sistance R1, since L has infinite admit-
directly with frequency. At dc or zero them, an imput voltage (VIN) is applied tance. At an infinite frequency, the port
hertz, the ideal inductor has zero ohms an an input current (IIN ) flows. admittance is zero, because the induc-
of resistance (a perfect conductor) and Admittance, measured in mhos, is the tance acts as an open circuit, and no in-
zero ohms of reactance. Therefore, we reciprocal of impedance. In other words, put current can flow.
can say that it also has zero ohms of admittance is the ratio of current to volt-
impedance-the vector sum of re- age. If an element's admittance is zero Analyzing the Gyrator. Now let's
sistance and reactance. However, as we mhos, no current will flow through it no apply these concepts to the gyrator cir-
move into the realm of ac, the reactance matter how high the voltage is across it. cuits (Figs. 1C and 2C). As in the equiv-
of an inductor increases according to the Such an element is a perfect insulator or alent circuits, R1 represents the ohmic
formula XL = 2'rrfL; where XL is mea- open circuit. On the other hand, an ele- resistance of the coil wire, and C and R2
sured in ohms; f (frequency) in hertz; ment with infinite admittance will con- are core losses which increase in step
and L (inductance) in henries. Its re- duct infinite current, even if a low voltage with the applied frequency. However,
sistance remains zero ohms. At infinite source is connected across it. It is a per- something new has been added -a gain
frequency, the inductor has infinite fect conductor or a short circuit. Combin- stage. Any active device can be used,
reactance, and will permit no ac to flow. ing these two terms, port admittance is but here we choose an op amp for its
So far we have been talking about an the ratio of the current flowing into the simplicity, high gain, almost infinite input
ideal inductor. Actually, every inductor port (IIN) to the voltage across the port impedance. and very low output imped-
has a certain amount of resistance and (VIN). ance. The gyrator op amps are strapped
capacitance as well as inductance. As Referring to Fig. 1B, we can see that for unity-gain, noninverting operation.
shown in Figs. 1A and 1B, an iron -core resistors R1 and R2 set the limits of port So, within the frequency limits of the de-
inductor can be modeled as an induc- impedance at both very high and very vice (assume infinite bandwidth), the
tance in series with a resistance, R1; low frequencies. At dc, the admittance of voltage at t ìe output is exactly the same
and this combination is in parallel with a the inductor L is infinite (a short circuit), as that at the noninverting input.
capacitance and series resistance, R2. and only R1 limits the current through it. If we apply a dc voltage across the in-
An air -core inductor (Figs. 2A and 2B) Capacitor C behaves as an open circuit put terminals of Fig. 1C, capacitor C
behaves as an inductance and series re-
sistance Rl would. In both cases, L is
fhe inductance of the coil, and Rl is the
- 'in
-tin tin
RI

resistance of the wire which comprises

the coil. The iron -core inductor contains
two additional elements, R2 and C,
which represent losses within the core.
With dc, there are no core losses, and
consequently, our model's C permits no
current to flow through R2. At higher and
nigher frequencies, core losses in-
crease. Thus, in our model, increased
current flows through R2 as the capaci-
tor's reactance decreases.
(A) (B) (C)

Synthesizing an Inductor. By com- Fig. Iron -core inductor (A) can be modeled as shown in (B)
1.
bining resistors and a capacitor with a and simulated using the gyrator circuit in (C).
58 POPULAR ELECTRONICS
 I in Ii lin RI
R1 should be no lower than the op
amp's minimum recommended load re-
sistance, which falls between 100 and
RI 2000 ohms for common op amp types.
The largest acceptable value for R1 is
desirable, so as not to load the op amp
yin Vin
too much, thus preventing high distor-
tion and heating effects. To simulate a
high-quality toroidally wound coil, R2
should be at least 100 times greater
than R1, but not so large as to become a
major contributor to the op amp's input
noise. As a rule of thumb, keep R1
(A) (B) (C) around 1000 ohms and R2 between 10
kilohms and 1 megohm.
Fig. 2. An air -core coil (A) has an equivalent circuit shown. Once the values of R1 and R2 have
(B). Op amp gyrator (C) simulates the coil's behavior. been chosen, use the formula C = L/
(R1)(R2) to find the required capaci-
does not conduct, and the voltage at the ground, which is the same behavior we tance in farads. At least 100 pF should
noninverting input is zero. The output is noted in the equivalent circuit. be used to avoid the detuning influences
also at ground potential, and because For frequencies between zero and in- of stray capacitances.
the op amp has very high output admit- finity, C and R2 act as a high -pass filter, It is important to keep the op amp
tance (low output impedance), we can causing less and less voltage drop functioning within acceptable circuit and
safely say that R1 is connected across across R1 as frequency increases, and signal parameters. If for any reason it
the port. So, I)N will flow only through thus less port admittance until R2's limit- begins to deviate from the role of a volt-
R1. This agrees with the behaviour of ing effect comes into play. The reactive age follower, the "inductor" won't work
the equivalent circuit of Fig. 1B. The port characteristics of the capacitor have properly. Input signals must lie within the
admittances are maximized at dc, limit- successfully been inverted or gyrated so operating bandwidth of the device, and
ed only by the values of both R1's (as- that the port behaves as an inductor. their amplitudes must not cause the out-
sumed to be equal). The equivalent inductance in henries is put stages to clip. In a gyrator, clipping in
At infinite frequency, C is a short cir- expressed by the formula L = (R1) (R2) the gain stage is analogous to core satu-
cuit, and therefore the voltage at the op (C), with resistances in ohms and capa- ration, which can cause high distortion
amp's noninverting input (as well as that citance in farads. levels.
at the output) is equal to VIN. Since there With the addition of two resistors, an However, this is not usually a prob-
is no voltage drop across R1, it is effec- air -core inductor can be simulated. Air - lem with gyrators. Because they will
tively removed from the circuit. The only core coils have essentially no "core" most often be operated from the same
admittance path is through R2 to loss, and therefore have no parallel re- power supplies that other audio stages
sistance in their equivalent circuits. Be- use, they will not start to clip until the
cause of this the gyrator (Fig. 2C) uses other amplifiers do. Unlike iron -core
PROPERTIES OF GYRATORS
the additional resistors to set the gain of coils, whose saturation characteristics
Advantages the op amp. When the values are prop- are functions of core material, size,
1. Immunity to ambient magnetic fields; no
erly selected, they provide enough gain number of turns, and applied current,
coupling or crosstalk between "induc-
tors."
to compensate for R2's losses at high the gyrator's saturation point is accu-
2. Very small size required for large val- frequencies. But the amount of gain rately predictable, and does not occur
ues of inductance. must be carefully chosen -otherwise before the other active stages of the sys-
3. Inexpensive, use readily available com- the circuit might oscillate! If R3 equals tem also saturate or clip.
ponents. R1 and R4 equals R2, the circuit will be Using either of the gyrators we have
4. Accurately predictable "saturation" lev- stable and exhibit no parallel resistance. examined will result in high-quality coils
els. In practice, however, little is gained over with inductances ranging from millihen-
5. Parameters can be fixed by choice of the circuit of Fig. 1C as long as the ratio ries to hundreds or thousands of hen-
resistors.
R2/R1 is at least 90 to 100, because the ries. Commonly available parts- includ-
Disadvantages
1. Active device generates noise (can be
effects of parallel resistance are negligi- ing relatively small capacitors -can be
held to low levels if proper devices are ble in most audio applications commonly employed. Added benefits include high
selected). encountered. magnetic field immunity and saturation
2. More complex circuits are required to characteristics, and (paradoxically)
simulate "floating" inductors. Practical Design. In synthesizing a small amounts of required printed circuit
3. Inductors with low series resistance and useful "inductor," the same basic rules board "real estate." However, there is
high current handling characteristics that govern the optimization of wound one limitation. The gyrators we have de-
are difficult and impractical to simulate, coils should be followed. For example, scribed are single ended. That is, one
as the circuits require high -power active series resistance R1 should be kept as side is grounded. To simulate "floating"
devices. small as possible and parallel resistance inductors, neither side of which is con-
4. Simulated inductors are frequency limit-
R2 as large as possible. This corre- nected to ground, more complex circuits
ed by their active devices' usable band-
widths and slew rates (not a problem at sponds to a coil wound from the heavi- using two op amps can be designed. But
audio frequencies in most cases). est wire practicable on the least lossy such gyrators are beyond the scope of
core available. For best performance, this article. p
JULY 1977 59
 "ZAP"
NEW LIFE INTO
DEAD Mtd BATTERIES
That dead cell may not be completely gone.
A properly applied high current can often clear a
fault, making the cell useful again.
BY DOUGLAS C. MYERS

THE NICKEL -CADMIUM cell is a pa- cells is discharged and recharged, the tire 25 mA and each cell's potential is
radox. Capable of being charged time available between recharges re- 1.25 volts, Ohm's Law tells us that each
many hundreds to many thousands of duces. Almost invariably, this is due to cell sees the equivalent load of 50 ohms.
times, it occasionally fails long before its the weakening of a single cell in the bat- Ideally, the four cells deliver identical
claimed life cycle comes to an end. Most tery. performance and, hence, share the load
people simply replace a cell that has To understand the cause of such a equally.
failed with a new cell. Considering that failure -one cell "dead" while the others In practice, no four cells in a battery
most Ni -Cd cell failures are reversible, are still good -refer to Fig. 1, a sche-
this is a waste of money. matic of a typical Ni -Cd power supply for
In this article, we will discuss the most small battery- powered devices. Without
common reason for early Ni-Cd cell fail- the charging source connected to the
ure and how the great majority of all fail- circuit, the 200 -ohm load "sees" 5 volts
ures can be reversed. The procedure and draws 25 mA from the battery of
described here will restore just about cells. Since each cell must pass the en-
any dead Ni -Cd cell to provide its entire
claimed useful life.

Why Cells Fail. In general, most de-

vices powered by Ni -Cd cells employ
more than a single cell. As the battery of

60 POPULAR ELECTRONICS
 CURRENT + small amount of material that forms the
LIMITING 1.25V
+ RESISTOR short could be removed, the cell would
CHARGE
VOLTAGE
1.25V
LOAD
20011
be restored to virtually its original capac- For maximum
1.25V ity once again.
1.25V CB performance,
Clearing the Short. Using the circuit
Fig. 1. Schematic of a typical shown in Fig. 2, the internal short can be know you're
NiCd supply for a small load. burned away in a few seconds. In opera-
tion, energy stored in the capacitor is exactly
ever exhibit exactly the same output rapidly discharged through the dead cell
voltage. Assume that one cell is deliver- to produce the high current necessary to "on- channel" with
ing only 1.20 volts, while the other cells
are delivering their rated 1.25 volts.
clear the short. Current is then limited by
the resistor to a safe charge rate for a
B&K PRECISION's
Now, the 200 -ohm load sees 4.95 volts small A cell. NEW FREQUENCY
and draws 24.75 mA. Since all four cells Several applications of discharge cur-
must pass the entire 24.75 mA, each of rent are usually necessary to clear a COUNTER!
the strong cells at 1.25 volts sees an cell. During the "zapping" (restoration)
equivalent load of 50.5 ohms. This process, it is a good idea to connect a
means that the weak cell sees only 48.5 voltmeter across the cell to monitor re-
ohms. While this does not seem to be sults. Momentarily close the normally
too unequal a distribution, note that the open pushbutton switch several times to
weak cell is working into the heaviest successively zap the cell, allowing suffi-
load and, as a result, will discharge cient time for the capacitor to charge up
more rapidly than the other cells in the between zaps, until the voltage begins
battery. Similarly, when the cells are re- to rise. Then, with the toggle switch
charged for only a short period of time, closed, watch as the potential across the
the weak cell, which has been working cell climbs to 1.25 volts. If the potential
the hardest, is also the one that receives
the least charging power.
CHARGE
This unequal loading and recharging 30011 SWITCH

is of little consequence in normal opera- 20-40+ SW

VDC
tion. The inequality is small for any given
charge or discharge cycle, due to the
relatively flat output voltage Ni -Cd cells ZAP Model 1827 $120
SWITCH
exhibit over most of their range. And a
good charge tends to equalize any ener- For the serious CBer, the 1827 and
gy differences between cells. However, accessory signal tap provide digital
during heavy usage, one is tempted to readout of transmit frequency, mobile
or base on all 40 channels. For best
"quick charge" the battery just enough Fig. 2. Shorted cell is cleared range and signal clarity, your trans-
to restore service. A combination of by energy stored in capacitor . mitter should be operating exactly
shallow charges and deeper- than-nor- on the assigned channels. The only
way to accurately check this is with a
mal discharges tends to exaggerate the stops before full voltage is reached, frequency counter.
energy difference between a weak cell some residual short still remains and
The new B &K- PRECISION Model 1827
and the other cells in the battery system. another series of zaps is in order. If you Is a full- feature battery portable fre-
Operated continually in this manner, the observe no effect whatsoever after sev- quency counter for only $120.
weak cell inevitably reaches its "knee," eral zaps and shorting out the cell and Typically reads to 50MHz with 1Hz
the point at which its voltage decreases taking an ohmmeter measurement indi- resolution
6 -digit display with switch allow-
sharply, long before the other cells cates a dead short, the cell is beyond re- ing 8 -digit accuracy
reach the same point. demption and should be replaced. Completely portable, use it in
At the knee, the picture changes dra- Once full cell potential is achieved, re- mobile or base
matically. Suddenly, the weakest cell move the charging current and monitor Optional SA -10 signal tap avail -
sees an increasingly heavy load, which battery voltage. If the cell retains its able for constant output frequency
causes its voltage to drop even faster. measurements
charge, it can be returned to charge and
This avalanche continues until the cell is Full range of optional accessories
eventually restored to service. But if the available
completely discharged, even as the oth- cell slowly discharges with no apprecia-
Available for immediate delivery at
er cells continue to force current to flow. ble load, the residual slight short should your local distributor.
The inevitable result is that the weak cell be cleared. To do this, short circuit the
begins to charge in reverse, which even- cell for a few minutes to discharge it, zap i;PIKPHECISION
tually causes an internal short. again, and recharge it to full capacity.
Once an internal short develops, re- Not all Ni -Cd cells can be restored by DYNASCAN
charging the cell at the normal rate is fu- the method described here, but most CORPORATION
tile. The short simply bypasses current can. After restoration, a cell's life expect- 6460 West Cortland Avenue
around the cell's active materials. (Even ancy will be roughly the same as that of Chicago, Illinois 60635 312;889 -9087
In Canada Atlas Electronics. Ontario
though the cell is apparently dead, most the other cells taken from the same Sri Sls Empire Eap 270 Newtown Rd Plainview. LI. NY 11803
.

of its plate material is still intact.) If the service application. O

CIRCLE NO 7 ON FREE INFORMATION CARD
JULY 1977 61
 1
with
frequency Counters
High-Performance -
Range See
e
68.69
pages
up to 1 GNz M
1977 Stereo FM-AM
SUMMER 1
-
Budget-Priced page 28
see
Aircraft

1{
NeW
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five- FUOCti°q See page 24
Clock
/Timer-
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Circuits

programmable
Plus PfOg Amateur
and
Courses in
Amateur
ra /or TV, Digital
Radio
Electronic
Radio- See pages
93, 95
Weather
Clocks and Service
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and Speakers,
rompiate se-
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Auto Accessories,and tats more
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the tateet
latest electronics
faction of
lection d satisfaction.

. .,GR CATALt
Le y ks ol He'
g,SCa-ec
Heath" ana

Heath Company, Dept. 10-31

Benton Harbor, Michigan 49022
62 POPULAR ELECTRONICS
 to come along are
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CIRCLE NO. 5 ON FREE INFO RMATION CARD
JULY 1977
65
Build d PINK NOISE GENERATOR
for AUDIO TESTING
Uses a new MOS noise generator IC.
BY DENNIS BOHN

AN INCREASING number of audio- White vs. Pink Noise. The output of octave be obtained? The solution lies in
philes are incorporating graphic the MM5837 is broadband white noise. cascading several stages of lag com-
equalizers into their hi -fi music systems. Since pink noise is used in most audio pensation so that the zeros of one stage
The new component is most often used work, it is helpful to understand the dif- partially cancel the poles of the next
as a "super" tone control that offers a ference between the two. stage. Such a network, shown in Fig. 2,
degree of frequency response compen- White noise is a composite signal with has a 3- dB/octave characteristic ( ±1/a
sation beyond the capabilities of bass contributions from all frequencies and a dB) from 10 to 40,000 Hz.
and treble controls. However, adjusting spectral density substantially indepen- The complete pink noise generator in
10 to 30 controls to compensate for dent of frequency (equal energy per Fig. 3 gives a flat spectral distribution
acoustic deficiencies in the listening constant bandwidth). It is characterized (per octave) over the audio band from
room can be challenging. This proj- by a 3 -dB increase in amplitude per oc- 20 to 20,000 Hz. An 11.5 -V p-p random
ec:t-a pink noise generator-makes the tave of frequency change. In compari- pulse train appears at pin 3 of the IC,
job a little easier. It provides a reference son, pink noise has a flat amplitude re- and is attenuated by the filter. The actual
signal for performing equalizer adjust- sponse per octave of frequency (equal output across C5 is about 1 V p -p ac of
ments, and uses just one IC and a few energy per octave). Pink noise allows pink noise riding on an 8.5 -V dc level.
passive components. correlation between successive octave
The IC, National Semiconductor's equalizer stages by insuring that the Construction. Since the circuit is fair-
MM5837, is a digital pseudo- random se- same amplitude of input signal is used ly simple, it can be constructed on a
quence generator which will produce a for each as a reference. small circuit board using printed circuit,
broadband white noise signal for audio The network required to convert white point -to -point wiring, or Wire-Wrap tech-
applications that's converted to pink noise to pink noise is simply a 3 -dB/ niques. Resistors in the filter network
noise by a passive filter. Unlike tradition- octave low -pass filter; but it presents an should have close tolerances. Premium -
al semiconductor junction noise interesting problem in circuit design. If grade tantalum and polystyrene, ceram-
sources, the MM5837 provides uniform capacitive reactance (and thus the re- ic, and film capacitors are recom-
noise quality and output amplitude. Al- sponse of a simple RC or first-order fil- mended. Observe standard precautions
though it was originally developed with ter) varies at a rate of 6 dB /octave, in handling the MOS device, and use an
electronic organs and synthesizers in how can a slope of less than 6 dB/ IC socket or Molex Soldercons.
mind, it is equally suited to room equali-
zation applications. A block diagram of
the MM5837 is shown in Fig. 1. PARTS LIST
C1 -1 -p.F, 35 -V tantalum capacitor
vss C2- O.27 -µF, 35 -V tantalum capacitor
I(4) C3, C4-0.047 -µF capacitor
Fig. Block
1.
C5- O.033 -µF capacitor
diagram of the C6- 100-p.F, 35 -V electrolytic capacitor
SHIFT REGISTER IC4- MM5837 noise generator IC
MM5837 R1 -6800-ohm, r/a -W, 5% resistor
OUTPUT noise source. R2 -3000 -ohm, l/a-W, 5% resistor
(3) R3- 1000 -ohm, r/a -W, 5% resistor
CLOCK OSCILLATOR R4- 300-ohm, 1 -W, 5% resistor
+15V Misc. -Circuit board, 15 -volt regulated sup-
I(2) j(1)
ply, output jack, output connector, IC sock-
VCC VDO
et or Molex Solderco3s, hookup wire, sol-
der, suitable enclosure, etc.

RI
6.8 K
R2
3K IK3 30011
O O
INPUT OUTPUT
t t
Fig. 3. Schematic
Ì
CI

yF
(4.OÇ( diagram of the
pink noise
generator.
F'ig. 2. Low -pass filter with
3-dB /octave response. POPULAR ELECTRONICS
66
 "Breaker ...breaker ... "

The
World of
Electronics
BY FRANK BOLLE

JULY 1977 67
 AVERAGE, PEAK, AND RMS VALUES
What is meant by the various ways of specifying ac potentials and currents.
BY HECTOR FRENCH.

WHEN dealing with dc potentials, and capacitor are simply reversed.) put in terms of rms with sine waves.
there is no ambiguity about what The average voltage is important for What about nonsinusoidal waveforms?
kind of voltage is meant. A dc volt is a dc two different reasons. First, it is easy to If we take a 117 -volt sine wave and
volt. When it comes to ac voltage, how- find with simple circuits. Second, it is allow only one alternation in 10 to come
ever, the picture is very different and of- reliably close to the rms voltage with through, the peak potential is still 164.66
ten confusing. For example, a potential sine waves. The basic circuit for finding volts. Since only a half wave out of every
specified as 100 volts ac has little or no the average ac voltage is illustrated in 10 cycles comes through, our average
meaning unless it is followed by an iden- Fig. 2. potential would be divided by 10
tifier like "peak," "rms," "average," or In this case the output is a series of (104.52/1C, = 10.452 volts).
"effective," each of which has a different half -waves of the same polarity. (Again, If we allow only one alternation in 10
meaning from the others. to change the output voltage polarity, cycles to come through for a 117 -volt ac
To illustrate what we mean, consider simply reverse the diodes.) A meter rms waveform, we cannot simply divide
your common 117 -volt ac power -line po- paced between the output point and by 10 to find the new rms potential. First,
tential. This figure specifies the rms volt- ground provides the reading and is usu- we must square 117, which yields
age of the power line. The peak potential ally calibrated with a scale that is com- 13,689. Then, we find the average by di-
is actually 164.66 volts, which is 39.8% pressed just the right amount to give a viding 13,689 by 10, yielding 1368.9. Fi-
greater than the rms potential. The aver- relatively accurate rms reading with nally, we must find the square root of
age potential, at 11% lower than the rms sine -wave signals. This is the type of cir- 1368.9, which results in 37 volts rms.
potential, is 104.52 volts. cJit used in most ac voltmeters ranging This last figure is a long way from the av-
The peak voltage is the maximum po- from inexpensive portable to expensive erage reading of this one -in -10 wave-
tential of the entire waveform. This volt- laboratory instruments. form, even when the average scale is

Fig. 1. Simple RC and

diode circuit is used
to find peak potential.

Fig. 2. Series of half

waves is measured to
find average value.
age is extremely important for designing At this point, you are probably won- compressed to indicate in make -believe
the insulation of high -voltage ac circuits. dering where rms voltage comes into the rms. Using the compressed scale, the
An 11,500-volt (rims) line, for example, picture. Well, the purpose of the rms indicated reading would be almost 70%
has a peak potential of 11,500 + 4577 = measurement is to specify the dc volt- low!
16,077 volts. That difference of more age that has the same power capacity As you can see from the foregoing,
than 4500 volts must be considered as the ac voltage it represents. "Rms" when dealing with pure sinusoidal wave-
when specifying components. stands for "root mean squared," which forms, you can use a peak -, average -, or
The peak potential is easy to find with is shorthand for saying that to find the rms -indicating circuit to convert from
the circuit shown in Fig. 1. rms voltage, you must square the ac one type of ac voltage to another without
The capacitor charges up to the peak waveform, find the average of the introducing errors. But when you are
voltage during the first positive alterna- squared waveform, and find the square dealing with nonsinusoidal waveforms,
tion of the ac input. The charge then root of that average. About the only sim- watch out. All your readings might be so
slowly drains off through the resistor un- ple way of showing an rms detector sys- grossly inaccurate as to be useless for
til the next positive alternation comes tem is as in Fig. 3. anything other than to indicate the pres-
along. (For a negative output, the diode The average -law circuit gives an out- ence or absence of a potential.

Fig. 3. Simple block diagram of an rms detector circuit.

68 POPULAR ELECTRONICS
 BUILD A

SOLAR CONTROLLER
Electronic temperature comparator
for solar energy systems or attic fans
BY JERALD M. COGSWELL

THE SEARCH for new energy nate operation of the overall system. The Solar Controller is a temperature
sources has encouraged amateurs Because the backyard (or rooftop) ex- comparator that turns on a blower or
as well as professional engineers to ex- perimenter may be discouraged by the pump when the air or fluid in the solar
periment with solar energy hardware as high cost or unavailability of suitable collector is at a sufficiently high temper-
used in space heating. A typical solar controls, the Solar Controller described ature to justify a transfer to the storage
heating system consists of three func- here should come in very handy. It can medium. In the fan application, control is
tional parts: solar energy collection, heat be built for about $35 and can be easily by the temperature difference between
storage, and heat distribution. Automatic adapted to turn on attic fans when need- the attic and outside air (or between ceil-
controls are required to operate the ed. It thus reduces the cooling load and ing and floor of a large room).
fans, blowers, pumps, etc. and coordi- prevents costly over-running of fans.
+12v Circuit Operation. The basic con-
troller circuit is shown in Fig. 1. In ¡Cl, a
voltage comparator, the resistances of
two temperature- dependent resistors
(TDR1 and TDR2) are compared, with
TDR1 placed in the storage medium and
TDR2 in the solar collector. When TDR1
STORAGE
is warmer than TDR2, its resistance is
higher and the higher voltage at the in-
K2
verterting ( -) input to ¡Cl keeps its out-

PARTS LIST
C 1,C2- O.05 -p.F, ceramic disc capacitor
COLLECTOR
C3,C5-500 -p.F, 25 -V electrolytic capacitor
C4,C6- 200 -p.F, 25-V electrolytic capacitor
D1-General-purpose silicon rectifier diode
Fig. Comparator ICI turns on or off depending on resistances of
1. D2,D3 -12 -V, 1 -W zener diode (1N4742, or
TDR1 and TDR2. When ICI is on, Ql and the relays are energized. similar)
D4 6 -V, -W zener diode (1N4734 or simi-
1

lar)
02 IC1 -710 voltage comparator
2N5295
+12v K1-12-V, 600 -ohm coil relay
K2 -24-V, 10- ampere contacts relay
12.6 V
R5
47On
Q1- 2N3392 transistor
Q2,Q3- 2N5295 transistor (or similar)
R1-7500-ohm, 1,-W resistor
R2,R3 -5000 -ohm multi -turn trimmer poten-
tiometer
R4- 10,000 -ohm, 1-W resistor
R5,R6,R7-470 -ohm, l. -W resistor
03 T1,T2- 12.6-V, 300-mA transformer (Radio
Shack 273 -1385 or similar)
TDR1,TDR2- TG-1 /8, 100-ohm, ±5ßb Sensi-
tor
D4
IN4734 Misc.-Suitable enclosure, perforated or pc
-6v board, socket for ICI, twin lead cable for
sensors, heat sinks(2), power cord, mount-
ing hardware.
I2v Note: The Sensitors are available from Texas
Instruments semiconductor dealers, or from
Texas Instruments, 2916 Holmes St., Kan-
Fig. 2. The power supply for the solar controller is standard sas City, MO 64109 at $2.40 each.
design and provides regulated positive and negative outputs.
JULY 1977 69
put in the low state. When TDR2 gets
warmer, the voltage across it gets higher
Portable
60-Hz "CLOCK"
and, when it is about 5 millivolts higher
than the voltage across TDR1, the out-
put of ICI goes high.
When this happens, transistor Q1 is
turned on and activates low -power relay
K1. The latter, in turn, activates a 24-volt
heavy -duty relay, K2, which handles the
OSCILLATOR
power requirements of the system. Crystal -controlled time base for field use.
Capacitors Cl and C2 prevent tran-
sients from affecting the inputs of 1C1.
Trimmer potentiometers R2 and R3 are BY CHARLES F. SMITH
used to preset the voltages on /Cl. Di-
ode DI is a general -purpose silicon rec-
tifier used to protect the contact of K1. If
desired, 01 can be replaced by a power
MOST digital clocks and sports tim-
ers are energized by the ac line
not so much for power as for the 60 -Hz
- How It Works. The integrated circuit
used in this time base is an MM5369, a
recently introduced 17- stage, mask -pro-
transistor (such as RCA 40594) and one frequency that is used as the time base. grammable oscillator /divider. Although
of the relays can be eliminated. This means that such digi °al devices masking options are available for use
The power supply for the Solar Con- cannot be used in vehicles or boats or with almost any crystal frequency, the IC
troller is shown in Fig. 2. used operates with a low -cost, readily
3.58MHz
OUTPUT available 3.53 -MHz color -TV crystal and
Construction. All components except delivers 60 I-z at its output pin. Trimmer
the power transformer and relays can be C3 capacitor C2 allows for exact frequency
71 6
mounted on a 3" x 6" piece of perforated 51
adjusting, and a buffered 3.58 -MHz out-
3°"1E-
board or pc board. Use small solder IC
MM5369
RI
I
XTAL
03.58 put is available. Current drain is approxi-
clips for connections to TDR1, TDR2 CI
20M T MHz mately 1.2 mA with a 10 -volt supply.
II 2I 31 41
and the relay. The entire system can be
mounted in any type of enclosure. Use a Tl
+3-I5V
NC
6- 36 pF Construction. Because of the high
heat sink for Q2 and Q3. 60Hz GND
G
OUTPUT frequencies nvolved, a small pc board
The temperature sensors can be (or perforated board) such as that
mounted at a distance from the rest of
Fig. 1. Schematic of circuit.
shown in Fig. 2 should be used. Figure 2
the circuit provided the resistance of the PARTS LIST also shows component installation.
interconnecting leads does not exceed a Since the IC: is a MOS type, take the
few ohms. Use #14 wire or conventional CI- I.2-i.F, 35 -V tantalum capacitor usual precautions when installing.
slender twin leads. Solder the leads to C2-6 -36 -pF trimmer capacitor
the sensors carefully (and quickly) and C3 -30 -pF capacitor
ICI-MM5369 programmable oscillator/ Adjustment. If you have a frequency
anchor the soldered ends in silicone or counter, or a calibrated oscilloscope,
divider, for use with a 3.58 -MHz crystal
epoxy. Be sure the bodies of the resis- (National) check for the presence of 3.579545 MHz
tors are exposed to insure fast thermal R 1- 20- megohm 1/4 watt resistor at pin 7 of the IC. You can adjust trimmer
response to temperature changes. XTAL-3.579545 -MHz color -TV crystal capacitor C2 for the correct value. If you
Note: The following are available from Bill
Godbout Electronics, Box 2355, Oakland do not have a frequency counter, use
Adjustment. Set trimmer potentiome- Airport, CA 94614: etched and drilled pc the Lissajous- figure approach with a
ter R2 at about its 3/4- resistance point. board ¡068) at $2.50; complete kit of parts, scope, with the output of a conventional
Then place the body of TDR1 in a bowl including board at $5.95. California resi- 6 -volt transformer as the horizontal
of water that has been heated to the av- dents, please add 6% sales tax.
sweep and the output of IC1 pin 1 for the
erage temperature you expect in the vertical signal. Adjust C2 until a very
storage medium. Place TDR2 in another for timing outdoor events that are not slow- moving square appears on the
bowl of water that is between 5° and near an ac power outlet. scope. If you have neither a counter nor
10 °F hotter than the first bowl. You will The 60 -Hz crystal -controlled time a scope and are planning to use the
have to determine the exact tempera- base described here (Fig. 1) can be clock with a portable timing device, use
ture difference you want the circuit to de- powered by any dc supply between 3 some form of accurate time signals such
tect. and 15 volts. It has low power consump- as those from WWV, CHU, etc., to start
Once both temperature sensitive de- tion, is stable within 2 parts per million the timer at a one -minute "beep" and
vices are in their water bowls, and the and is small enough to fit inside the case stop it at the next minute "beep." Adjust
water temperature difference is what of many digital clocks and timers. C2 to obtain the correct time interval. O
you want, adjust trimmer R3 until relay
K.1 activates. The circuit can be made as
sensitive as your needs demand. Note
also that although the device appears Fig. 2. Actual -size etching GNU
C3
passive when both probes are at room and drilling guide (far
11
temperature, a gust of warm breath, or right) and component 60NZOUT

the touch of a finger on TDR2; or a drop layout. Components are *3-,5 vDC
cf cool water on TDR1, will cause Kl to mounted on nonfoil side.
be energized.

70 POPULAR ELECTRONICS
 Chances are, the name on his radio will Of course, there's one feature a Motorola
be Motorola'? CB offers that's not in the specs.
The same Motorola that now makes a And that's reliability.
CB radio for your car. Police get it
Like our professional radios, a Motorola with the name
CB is exceptionally simple to operate. Motorola.
It has features like gain control, audio So can
compression, and noise limiting built in, you.
fully automatic.
The result is truly outstanding talk/
listen performance. Because the radio is in
control. Rather than you.
A digital phase lock loop synthesizer
makes tuning precise. Again, automatically.
A professional -quality 3% -inch top-
fire speaker produces an audio fidelity
that must be heard to be fully appreciated.
A Motorola CB is completely solid state
and standardly equipped with a power mic
that doesn't have batteries that can fail.
That doesn't cost extra.

Motorola CB
From the voice of experience in 2 -way radio.
To find the dealer nearest you, write: Customer Relations Manager, Motorola Inc., Automotive Products Division, 1299 East Algonquin Rd., Schaurnburg, Illinois 60196.
Motorola is a registered trademark of Motorola Inc.
CIRCLE NO 29 ON FREE INFORMATION CARD

www.americanradiohistory.com
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MAGAZINES AT DISCOUNT?
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special introductory rates shown below -up to 50% off! To
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write :o: MAGAZINES AT DISCOUNT, A Division of Ziff -
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72 POPULAR ELECTRONICS

www.americanradiohistory.com
AmericanRadioHistory.Com
 ONE-TOUCH 'SAVE!' MONEY TIME FREIGHT
QUALITY STEREO EQUIPMENT

DIODE TESTER l( TION

AT LOWEST PRICES.
YOUR REQUEST FOR QUOTA-

Identifies good/bad diodes, and tells

RETURNED SAME DAY.
FACTORY SEALED CARTONS
GUARANTEED AND INSURED.
-
which end is anode/cathode. SAVE ON NAME BRANDS LIKE:
A.D.C. KLH
A.R. SHURE
BY DAVID MARKEGARD DYNACO KOSS
SONY FISHER
PIONEER
AND MORE THAN 50 OTHERS
BUY THE MODERN WAY
MOST electronics experimenters unknown diode lead connected to BP1 BY MAIL -FROM
seem to have plenty of diodes is easily identified.
in their junk boxes-either salvaged
from old equipment or purchased at low Construction. The circuit can be as-
bulk prices. The problem, usually, is to sembled on a small piece of perforated
find out which ones are good, which are board and mounted in small enclosure
bad, and, in the case of the former, along with the batteries in holders. The
which end is which (cathode or anode). two binding posts and the power on /off
Department 217S
Of course, most diodes can be tested switch should be mounted about an inch
using a conventional ohmmeter. How- apart on top of the enclosure. Put the 12 East Delaware
ever, there are simpler ways, and one is
to use the diode checker described
here. Simply by touching a diode's leads
two LED's in rubber grommets near BP1
and identify them properly.
Before installing the LED's, be sure
CIRCLE
Chicago, Illinois 60611
312 -664 -0020

FREE
A
NO. 23 ON INFORMATION CARD
to its binding posts (in either polarity), they are of equal brightness. The values
you can tell whether or not it is good and of RI, R2, R3, and Cl can be varied if
identify the anode and cathode.

How It Works. Op amp IC1 forms a

the specified values are not availa-
ble-as long as the circuit oscillates. FREE catalog
of over
simple square -wave oscillator whose Use. Connect a diode to be tested be-
output swings from almost full positive to
full negative levels with respect to
tween the two binding posts. If only one
LED glows, the diode is good and the 2000
small tools,
ground. glowing LED will identify the cathode. If
measuring
instruments,
PARTS LIST and supplies
RI
68K
SIA
B I ,B2 -9 -volt battery ELT

ICI BPI BP2 BPI ,BP2-Five -way binding post .COL -

741 o C 1 -0.
-p.F capacitor
I DRILLS

41 R2
XI ICI -741 op amp
LED ,LED2 -Red LED (about equal bright -
..FILM LOADERS..

-+-
10K LEDI ,LE D2 I PS. . .PAGES. . .GRAVERS

\\
ness) . GRINDERS... HAMMERS..
R I- {íR,000 -ohm resistor INCLINOMETEFS. . .JACKS. .

R3 R2,R3- 10,000 -ohm resistor KNIVES. LATHES. LEATHER

T
CI 10K
. . . .

S -Dpst switch
132
IyF 9V 1
ETTES LOUPES... MINIATURE
Misc. -Perforated board, socket for ICI, bat- TOOLS... METRIC TOOLS ...MULTI -

tery holder, suitable enclosure, grommets TESTERS ...NEGATIVE FILES...

for LED's, mounting hardware, etc. NIPPERS... OILERS... PIN VISES..
SIB
PLIERS... PROBES ...RIFFLERS...
, IC1 is square -wave oscillator. Tested diode turns on either LED. SCISSORS. . SNARES. . SOLDER-
ING SUPPLIES. . .TEST INSTRU-

. ':
MENTE. . TWEEZERS. . VIEWERS
good diode is connected between

T
If a both LED's glow, the diode is shorted. If ... VISES... WRENCHES..
BP1 and BP2 with its cathode toward neither LED glows, the diode is open. ADH \\%%
Coi ABRASIVES ...

BPI, LEDI is forward biased and glows. Transistor junctions can be tested by `O G...BOOKS

LED2 remains dark because it is reverse connecting the collector to BPI and the We 1;11 .EPDXIES.
S

biased. If the diode is reversed so that base to BP2. If LEDI glows and is f" .CALIPERS.
its anode is at BP1, LED2 glows and brighter than LED2, the transistor is npn. 49"
allai« National Camera
LED1 is dark. With the LED's properly If LED2 glows, or is brighter than LED1, 2000 Wes/ Union Ave. Dep,
identified and placed close to BPI, an Englewead,Cole, U.S.A. 41O1/0
the transistor is pnp.
CIRCLE NO. 30 ON FREE INFORMATION CARD
JULY 1977 75
 Announcing the NEW STANDARD in Stereo Testing!

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EAR... (no test instruments of any kind required) Record is also designed to be used as a highly efficient design and
measurement tool. In the following tests, recorded levels, frequencies,
Frequency response -a direct warble -tone check of nineteen etc. have been controlled to laboratcry toierances- affording accurate
sections of the frequency spectrum, from 20 tc 20,840 Hz, which numerical evaluation when used with oscilloscope, chart recorder, out-
will pinpoint any frequency response defects in your system. put meter, intermodulation -distortion meter and flutter meter.
1,000 -Hz square waves to test transient and high- frequency response
Separation -an ingenious test which indicates whether you have of phono pickups.
adequate separation for good stereo. 500 to 20,000 Hz frequency- response sweep.
Cartridge tracking -the most sophisticated tests ever devised Sine -wave tone -bursts to test transient response of pickup.
for checking the performance of your cartridge, stylus and Intermodulation test using simultaneous 400 -Hz and 4,000 -Hz signals.
tone arm. Intermodulation sweep to show distortion caused by excessive res-
onances in tone arm and cartridge.
Channel balance -two broad -band, random -noise signals which
permit you to eliminate any imbalances originating in cartridge, 1,000 -Hz reference tones to determine groove velocity.
amplifier, speakers or room acoustics. 3,000 -Hz tone for flutter and speed tests.
Sample waveforms -illustrating both accurate and faulty responses are
Hum and rumble -foolproof tests that help you evaluate the provided in the Instruction Manual for comparison with the patterns
actual audible levels of rumble and hum in your system. appearing cn your own oscilloscope screen.
Flutter -a sensitive "musical" test to check whether your turn- FR EE Instruction Manual Includes Detailed
table's flutter is low, moderate, or high.
Instructions, Charts, Tables and Diagrams.
Cartridge and Speaker Phasing Anti- Skating Nothing is left to chance or m'sinterpretation. Every segment of
. . .

every band is fully, clearly, graphica ly explained. You'll know exactly

Adjustment "Gun Shot Test" for Stereo Spread what responses to listen for in each test. Which sounds and patterns
Multi- purpose Musician's "A" Equal- tempered Chromatic
indicate accurate performance .. which ones spell trouble
. as well ...
as the cause of trouble and precise corrective measures to follow
Octave Guitar -tuning Tones. and help you pinpoint, analyze and cure your stereo headaches!
r Ziff -Davis Service Division, Dept. R, 595 Broadway, New York, N.Y. 10012.
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CHARGE YOUR ORDER TO YOUR AMERICAN
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CHARGE OR DINERS CLUB ACCOUNT. r City State Zip

76 POPULAR ELECTRONICS
 11 Solid State
By Lou Garner

IC's FOR TEST INSTRUMENTS

SURPRISING as it may seem, solid -state test instruments automatic ranging, frequency synthesis, automatic unit con-
were manufactured and used long before the transistor it- version, and digital counting and display.
self was invented. Featuring crystal diode circuitry, the early Introduced recently by the National Semiconductor Corpo-
-r
units were relatively simple instruments -f test probes, ration (2900 Semiconductor Drive, Santa Clara, CA 95051),
square -wave clippers, oscilloscope calibrators, dc reference the LH0091 is one of the latest IC's developed primarily for
voltage sources, outboard signal generator modulators, etc. test instrument applications. Suitable for use in digital voltme-
Historically, the transistor's first significant commercial use ters (DVM's) and digital multimeters (DMM's) as well as in
was in hearing aids. Shortly thereafter, however, the recently noise, vibration, audio and power meters, the new device is
invented device found its way into pocket AM radio receivers designed to generate a dc output equal to the true rms value
and, almost simultaneously, into portable test instruments. of any ac or composite ac /dc input signal from 0 Hz (dc) to 2
With its small size and low voltage and current requirements, MHz. With an inherent accuracy of 0.5% of reading, the de-
compared to the then standard vacuum tube, the new device vice can be adjusted using external trimming for accuracies
was certainly ideal for such applications. Initially, its use was down to 0.5 %. In typical applications, it has an input imped-
limited to such products as signal tracers, simple meter am- ance of 5000 ohms and an output impedance of 1 ohm. When
plifiers, and limited -range signal generators. Later, as better operated with a dual ±15 -volt dc power source, the LH0091
transistor designs were developed and manufacturing tech-
niques refined, transistors found their way into r-f signal gen-
erators, function generators, oscilloscopes, Q- meters, and
even microwave gear. As time passed, other solid -state de-

-0
15

14

Fig. 1. Simplified
che»iutic (A) aial
lead co ii ii eat iO H (B)
for LH0091 slits
converter IC.

1
A

vices were added to test instrument complements, including Al Al

FET's, SCR's, triacs, diacs, and LED's, culminating in the use IN F!!ItBACk AI V OUT A7 IEfOBACN

of integrated circuits. Today, almost all solid -state test instru- I4 11 10 9

ments use at least one IC and many a dozen or more. There

are, in fact, a number of special -purpose IC's designed speci-
fically for test instrument applications.
For the experimenter and hobbyist, the evolution of inte-
grated circuits and the ready availability of special purpose
IC's has made possible the home assembly of inexpensive
but sophisticated test instruments which would be both costly
and prohibitively large if based on the use of either vacuum
tube technology or discrete semiconductor devices. In addi-
tion, the development of complex IC's has permitted the effi-
cient use of advanced design concepts and techniques in test NC NC A5 1I 45 112 I A4f I
GNO

equipment design, including phase -locked loops, gyrators, B TOP VIEW

JULY 1977 77
 Reference HEATER SUPPLY Plastic Package
Temperature Stabilizer
p
as

as
B
1 BOTTOM VIEW

OA
04

at
10 pF .F.g. 2. National's
-i l
LM3999 voltage reference:
112
01 ,- (A) equivalent schematic;
e- 03 Oz s3V
(B) lead connections;
(C) voltage calibrator
f2
using the device.

will accept input signals of up to ± 15 volts peak. As shown in

the unit's simplified schematic diagram, Fig. 1A, the IC in-
cludes an uncommitted amplifier, A5, which may be used for
filtering, to provide additional gain, or for other applications. DO PUT
1Ou

Supplied in 16 -pin DIP's, with lead connections as identified in

Fig. 1B, the LH0091 is available in two versions -one in a
metal case, for the standard military temperature range ( -55°
to +125° C) and the other for commercial operation ( -25° to
+85° C).
A unique device, the LH0091 is, of course, but one of a sub-
stantial number of IC's developed specifically for test instru-
ment applications. Special, as well as general -purpose IC's
useful in test equipment designs, are available not only from accomplished through the use of a dual voltage -to-frequency
National Semiconductor but from virtually all other solid -state technique. One voltage -to- frequency converter generates a
device manufacturers, including AMI, Exar, Fairchild, Intersil, signal proportional to the input voltage while the other pro-
Motorola, Plessey, RCA, Signetics, Siliconix, and Texas In- vides a sample window and determines the clock frequency
struments. for counting the output of the first Requiring +5- and 15 -volt
Suitable for power supply and general purpose as well as dc sources for operation, the IC Features a temperature com-
test instrument applications, another National Semiconductor pensated reference and both autopolarity and over -range out-
IC, the LM3999, looks deceptively like an inexpensive transis- put indicators. With an input impedance of 500,000 ohms, the
tor, for it is assembled in a three -lead, type TO -92 plastic device offers a full -scale analog range of ±1.99 volts, a con-
package. Despite its simple external appearance, however, version time of 1 second, and an accuracy of ±'1.0 %. Two
the unit is a monolithic precision voltage reference which corn - versions of the IC are offered by the manufacturer, differing
bines a multi- device temperature stabilizing circuit with a zen- only in their temperature ratings. The standard DM7700 is
er controlled regulator, as shown in its equivalent schematic specified for operation from 20° to +95° C, the less expen-
diagram, Fig. 2A. Its pin connections are identified in Fig. 2B. sive DM8700 for operation from 0° to +50° C. Both versions
In operation, the LM3999 behaves as a highly stable 6.95 -volt are supplied in standard 24 -pin double -width DIP's, with pin
zener diode with a low dynamic impedance of only 0.5 ohm connections as identified in Fig. 3B, and both can provide
and an effective current range from 0.5 to 10 mA. Accepting adequate current drive for standard LED numeric displays. A
dc inputs from 9 to 36 volts, the separately powered stabiliza- typical application circuit for the DM7700 (or DM8700) is given
tion circuit permits operation from 0° to +70° C with a temper- in Fig. 3C. Except for the IC, the NSN -33 LED readout, and
ature coefficient of 0.0005 % /°C and a long term stability of 20 the dc power supply, the only components needed for opera-
ppm. The circuit for a portable voltage calibrator circuit, one of tion are three capacitors, three fixed resistors, and two poten-
the many possible test equipment applications for the tiometers.
LM3999, is given in Fig. 2C. Here, the LM3999 is used in con- After the multimeter and the oscilloscope, many technicians
junction with an LM312 operational amplifier. Supplying a pre- feel that the basic signal tracer is the next most valuable of
cise 10 -volt output level for equipment calibration, the instru- bench service instruments. Essentially a self- contained audio
ment requires a warm -up time of ten seconds, but may be amplifier with integral loudspeaker, the signal tracer can be
used intermittently without degradation of long term stability. used with appropriate accessory probes for checking radio
If your instrument project plans include one or more digital and TV receivers, CB transceivers, intercoms, PA systems,
meters, you'll want to investigate yet another new National tape recorders, record players, hearing aids, and stereo in-
Semiconductor device, the DM7700, a monolithic IC which stallations. The medium power audio amplifier IC's offered by
contains all of the active circuitry, except for display, needed many semiconductor manufacturers are ideal for assembling
for a 21/2-digit meter. As illustrated by its simplified block dia- signal tracers. A typical circuit is shown in Fig. 4. Abstracted
gram, Fig. 3A, the DM7700 comprises amplifier, reference from a Fairchild Semiconductor (464 Ellis St., Mountain View,
voltage, voltage -to- frequency converter, clock, time -base, CA 94042) data sheet, the design features a type TBA800
counter and latch circuits. Analog -to- digital conversion is monolithic audio amplifier IC. Assembled in a 12 -pin power
78 POPULAR ELECTRONICS
 Dual -In -Line Package
DIGIT
I-
A E D G B C or 2 1

TIME
REF
BASE
4 113 21 11 20 19 II 17 16 15 IE tl

AMP VIF COUNTER

DIGIT
OUTPUTS

.5V -15V ANALOG DIGITAL DECIMAL 7 S GM NT

GND GNO INPUT PLU DECIMAL 10
OUTPUT
A
IE, AN G C. , R, F V. r SCALE ZERO C. DPA D B Cwu. DIG
CND ADJ ADJ GND

B
Vcc
Fig. Functional block diagram (A),
3.
lead connections (B), and
typical application circuit (C) VEE k/vNI EE V

for DM7700 analog -to- digital REE

meter converter integrated circuit. ANAL OG

GADANO
SCALE
V.EE

ADJUST
1 SCALE
ADJ

ANALOG
GND

R.EE

0647700 NSN33
ZERO
ADJ
ZERO
ADJUST

DPA P DPA OP

DPB 11. DPB 02

Cwua 01

DIGITAL
03
GROUND GND

BYPEY EII ,PP".

package with external cooling tabs, the TBA800 has a max-

V-2eV imum voltage rating of 30 V and a maximum peak current ca-
o
I C9 I C6 pability of 2 A. With a modest heat sink, the device can deliver
T 0 1 NF T
1 100 uF
25 V
RL 16 Cl
up to 5 watts to a 16 -ohm load. At moderate output levels, the
amplifier has a specified frequency response flat within 3 -dB
L C2
from 40 Hz to 20 kHz and an open -loop gain of 80 dB, with a
INPUT
500 NF typical total harmonic distortion of only 0.5 %. Requiring but
15 V
80 -mV input for full output, the IC's input resistance of 5.0
loo NO
TABS \
4
12
megohms permits it to accept all standard test probes. Prop-
erly matched to its load, the TBA800 is rated for 75.0% effi-
ciency at full output. Referring to the schematic diagram, the
C3 circuit requires an external 24 -V dc source for operation. This
may be provided by batteries or by a well -filtered line- operat-
ed power supply, as preferred. All component values are
c1
100 pF
6V
- C7
- C4 specified except for C3 and C7, which are part of the compen-
sation network. These capacitor values are chosen to provide
RFA the overall frequency response needed for the circuit's ap-
56 C)
plication. Generally, C7 will be approximately five times as
large as C3. For most projects, C3 can be a 330 -pF low -volt-
age ceramic capacitor and C7 a 1500 -pF unit.
Fig. 4. With a TBA800 audio amplifier, this circuit Although special -purpose IC's are ideal for instrument de-
can be used to make a basic signal tracer. signs ranging from digital meters to multi- output function gen-
JULY 1977 79
erators, operational amplifiers, as a broad class, are probably each step is determined by the initial clock frequency while
the most versatile of all IC's for general test equipment ap- the number of steps per cycle and hence the cyclic rate is es-
plications. Op amps may be used, typically, in sine -wave os- tablished by the dc reference voltage applied to the 311 corn -
cillators, pulse generators, oscilloscope preamps, active fil- parator.
ters for signal analysis, bridge amplifiers, frequency meters, Looking to the future, the next major evolutionary step in
and staircase generators. Two representative examples of the test instrument design probably dill be the increased use of
many possible op amp test equipment circuits are given in microprocessors and memory circuits. The use of these de-
Figs. 5 and 6. Both circuits were abstracted from application vices will permit the development of a whole family of auto-
notes published by Intersil, Inc. (10900 N. Tantau Ave., Cu- matic test instruments ...
units capable of performing a
broad series of tests and, perhaps, of even changing the test
R7
+15v
R6
4,7
fR7 procedures on the basis of initial results. More sophisticated
5K 4.7 K
future instruments may even provide aural outputs, telling the
service technician where a circuit defect is located and which
component or device should be replaced.

Reader's Circuit. Faced with frequent power interruptions

R3 R5 in his area and having electrical equipment which required
7? K -15V 51 K

7K
special start-up procedures if the ac power was removed for
R4
CI
more than a few seconds, reader John M. King (1194 Idylber-
100K
7147609 AMPLITUDE
O1 yF
ry Road, San Rafael, CA 94903i devised the protective con-
ADJUST
trol circuit shown in Fig. 7. The control is designed to maintain
power -line contact with the protected equipment for short in-
Fig. 5. Op amp Wein bridge oscillator
described in an Intersil application note. tervals in the event of a power 'allure, but to disconnect the
equipment if the failure period exceeds a preset limit.
pertino, CA 95014), both feature FET -input op amps, and both As shown in the schematic diagram, line power is applied to
are designed for operation on standard ± 15 -volt dual dc power the external equipment connected to the dual outlet (SO1)
sources. through the contacts of relay K1 which, in turn, is controlled by
Capable of delivering an output signal of 20 volts peak -to- a solid -state sensing circuit. Step -down transformer Ti in con-
peak, the Wein Bridge oscillator circuit shown in Fig. 5 may be junction with bridge rectifier RECT1 and filter capacitor C1
used either alone as a test-tone source or as part of a com- form a dc power supply for the control circuit. Equipment oper-
plete audio-signal generator design. A type 8007 op amp ation is initiated when pushbutton Si is depressed, turning on
serves as the basic oscillator, with a 2N2609 JFET used as a SCR1 and energizing Kl. With SCR1 conducting, a dc charge
feedback element to provide amplitude control. In operation, is maintained on C2 by current flow through blocking diode
the circuit's output frequency is determined by the values of D1. Should a momentary power failure occur, SCR1 will con-
the resistors and capacitors in the bridge feedback network tinue to conduct until Cl is discharged below the SCR's
and may be calculated from maintenance voltage, holding Kl closed and permitting the
immediate reapplication of power to the external equipment.
fo = 1 /27rRC, Thereafter, the SCR will switch to a high impedance state,

IR5047
where the frequency, fo, is in Hz, R is in megohms and C in
ELF. Multiple output frequencies may be provided by using a
number of different RC values, selected by means of a suit-
able multiposition switch. Continuous frequency coverage
within a broad range can be obtained by replacing the two fix-
ed resistors in the feedback network with a matched -pair gang
potentiometer. The two techniques can be combined, of
course, with switch selectable capacitors establishing differ-
ent ranges and continuous coverage within each range pro- ID 100
vided by the ganged potentiometers. LEAKAGE
LO1'J
DIODE PAIR
Suitable for use in a variety of test equipment designs from
counters to characteristics curve analyzers, the staircase gen- VOUT VREF
erator circuit illustrated in Fig. 6 develops a cyclic stepped out-
put signal waveform. Its active device complement includes a
Fig. 6. Another Intersil circuit shown here
type 8043 dual op amp, a pair of low- leakage diodes, a type is an op amp staircase generator.
1H5042 CMOS analog switch, and a type 311 voltage com-
parator. In operation, a high- frequency clock (square-wave) opening the relay. However, a small gate voltage will be main-
signal is applied to the first op amp, half of an 8043. Amplified, tained on the SCR for a short while by the accumulated
this signal drives the second op amp, which, in turn, charges a charge on C2. Thus, if ac line power is restored before C2 is
0.02 -1.LF capacitor in small steps through a pair of low- leakage discharged below the level needed to "fire" the SCR, circuit
diodes. The capacitor's instantaneous voltage level is con - operation will be initiated automatically. If the power failure in-
tinuously compared to an externally applied dc reference by terval is longer than the time required for Cl and C2 to dis-
:he 311 voltage comparator. When the capacitor voltage charge, operation must be restarted manually by depressing
reaches the preestablished level, the comparator applies a S 1, permitting the operator to carry out any necessary start-up
signal to close the analog switch, discharging the capacitor to procedures required by the protected equipment.
end the cycle and reset the circuit. The relative time width of John used Motorola semiconductor devices in his design,
80 POPULAR ELECTRONICS
 Fig. 7. This circuit
maintains power -line
contact during short
power outages but will r
disconnect the equipment
if failure exceeds
a preset simit.

with the bridge rectifier a HEP type R0801, SCR1 a HEP type TO-39 and plastic TO -92 packages, the new regulators are
R1216, and diode D1 a HEP R0050. The step -down trans- available with outputs ranging from 5.0 to 24.0 volts. All of the
former may be any standard type with a 12 -volt, 500-mA sec- devices are protected by internal current limiting and thermal
ondary. Resistors R1 and R2 are half -watt types. Capacitors shutdown circuitry.
C1 and C2 are 16 -volt electrolytics. A 12 -volt dc relay with a International Rectifier's Semiconductor Division (233 Kan-
95 -ohm coil and contacts rated at 10 A is used for Kl, while sas St., El Segundo, CA 90245) has recently introduced a pair
the control switch, Sl, is a spst, momentary contact, NO of 900 -volt npn transistors with power dissipation ratings of 50
pushbutton or lever type. Finally, the receptacle (SOl) is a fa- watts. Designated types IR 708 and 709, the new units are
miliar 3 -wire dual wall outlet. suited for applications in video deflection circuits, high -voltage
With neither layout nor lead dress critical, the circuit can be switching power supplies, power controls, and switching regu-
duplicated using any preferred construction technique but, for lators. Both offer continuous collector current ratings of 3 A
maximum safety, the wiring should be housed in a sturdy (and with fall times of 1.5 µs, and both are supplied in standard
grounded) metal case or box. According to John, the time de- TO-3 metal cases.
lay before manual resetting is required can be adjusted (by
means of R3) between 1 and 12 seconds, which is more than
adequate for most momentary power interruptions. If, for
some reason, a longer delay is required, this may be achieved
by increasing the values of C2, R2 and R3. Delays of up to a
minute or two should be feasible with standard components.

Device /Product News. RCA's Solid State Division (Box

3200, Sommerville, NJ 08876) has added a new series of de-
vices to its growing family of BiMOS (Bipolar /MOS) operation-
al amplifiers, which feature MOSFET inputs and COS /MOS
outputs. The new CA3160 series are frequency- compensated
versions of the earlier CA3130 series op amps, and feature
gate -protected p-channel MOSFET's in the input stage to pro-
vide input impedances of 1.5 x 1012 ohms (typical), very low
input currents (5 pA typical at 15 V), and exceptional speed
performance. In each, the output stage employs a comple-
mentary- symmetry MOS transistor pair capable of swinging
the output voltage to within 10 mV of either supply voltage ter-
minal, permitting direct interface with either CMOS or bipolar
7400 TTL series devices. Other features include wide band-
Put more
width (15 MHz), high slew rate (10 V /µs unity-gain follower),
and strobbing capability to reduce standby power consump-
punch in your work.
tion. Suitable for applications in sample- and -hold amplifiers,
With a Greenlee Chassis Punch you can punch
long duration timers, wideband amplifiers, voltage followers,
clean, true holes in seconds. Round, square,
voltage regulators, Wein Bridge oscillators, VCO's, and pho-
key or D. In 16 -ga. metal, hard rubber, plastic
to -diode sensor amplifiers, the devices are offered in both
standard and dual -inline formed 8 -lead TO-5 packages.
or epoxy. Available at radio and electronics
In addition to its special purpose test instrument IC's, Na-
parts dealers. Write for catalog E -730.
tional Semiconductor has announced a new family of positive
Greenlee Tool Co, Rockford, III. 61101.
regulators with several fixed output voltages in three tempera-
ture ranges. Identified as the LM140LA series, the new de-
GREENLEE TOOL CO
vices have a 2.0% output voltage specification, 0.04% /volt
a subsidiary of
line regulation, a 0.01 % /mA load regulation, and can deliver Ex- Cell-O Corporation
up to 100 mA with adequate heat sinking. Offered in metal
CIRCLE NO 21 ON FREE INFORMATION CARD
JULY 1977 81
 timing capacitor. The 556 dual timer
makes it easy to double the time delay of

?TVA Experimenter's
a single 555 by connecting the output of
the first chip to the input of the second.
After the first timer completes its timing

Corner cycle, it triggers the second timer.

A timer using this principle is shown in
Fig. 3 where R2 and Cl determine the
time delay of the first timer and R3 and
By Forrest M. Mims C4 determire the delay of the second
THE 556 DUAL TIMER timer. The output of the first timer is cou-
pled to the input of the second by C5.
Operation of the circuit is straightfor-
IF THERE'S anything better than the generator. The tone continues until the ward, and you should easily be able to
popular 555 timer, it's the 556 dual one -shot's timing cycle is complete. The generate time delays of more than
timer. The 556 is two 555's on a single result is a tone burst which you can use twenty minutes. Though Fig. 3 shows
chip packaged in a 14 -pin DIP. The pin for signaling, alarms, electronic mu sic, potentiometers for R2 and R3, you can
outline of this versatile chip is shown in and other effects. use fixed resistors if you prefer. The po-
Fig. 1. Either or both halves of the 556 You can experiment with the various tentiometers, of course, are handy for al-
can be used for all the standard 555 ap- timing and frequency-controlling compo- tering the delay of each half of the timer.
plications. This month, we'll look at sev- nents (R1, Cl, R2, R3 and C4) to pro- You can also use a range of values for
eral that use two 555's and are therefore duce different sound effects. Remember Cl and C4. Naturally, large -value capa-
ideally suited for the 556. that you're looking for a tone which con- citors will give long time delays; but if
you only need a delay of a few minutes
p /SCNARGE CG SUPOLY or so, you can use less costly units.
Finally, though the main purpose of
TNRES/OLD z D/SCNARGE M this circuit, which I've borrowed from
CONTCOL /2 TNRESNOLO
Signetics, is to extend the time delay of
VOLTAGE
a single 555, you might want to take
T/MER / 556
RESET (TOP)
CONTROL-
VOLTA GE
Fig. 1. Pin outline advantage of the first timer's output, too.
-r/MER of the 556 timer. Lots of interesting sequencer applica-
2
OUTPUT RESET tions are possible since each timer can
OUrPL/T be adjusted for a different timing period.
TR /GGER

GNP TR/GGER Extra-Long Time-Delay Circuit. A

neat way to increase the time delay of a
single 555 by a factor of ten is to connect
Tone -Burst Generator. Figure 2 tinues after 51 is released, so adjust R1 a low -cost TTL decade counter like the
shows a circuit for a tone -burst genera- until this occurs. 7490 to the basic timer circuit. This trick
tor using a single 556 dual timer. The can provide time delays of up to a few
first half of the 556 is connected as Dual -Action Timer Circuit. The hours -even more if you use a high -
a monostable multivibrator (one -shot) maximum time delay of a single 555 tim- quality timirg capacitor.
whose timing period is controlled by R1 er is limited to ten or fifteen minutes un-
and Cl. The second half of the 556 is less you use an expensive low- leakage
connected as an astable (free -running) O/6V
multivibrator which produces an audio Fig. Dual -action
3.
R2
tone with a frequency governed by R2, timer circuit $R/
22222/OK
/M
/O /41

R3 and C4. using the 556 IC.

Normally the speaker is quiet; but 556
when pushbutton switch SI is pressed,
the one -shot begins its timing cycle
while simultaneously activating the tone oOF
7
C2
/1 1 C3 c4,*
/o0/..F
.a/ EGA PSEO
TIME
/NO/CATOR
)1E"sEE TEXT

R314'
sO0n

Fig. 4. Extra-long
time delay circuit.
TREPziCE To /NCREASE VOLUME,

Fig. 2. Tone -burst generator.

82 POPULAR ELECTRONICS
 Operation of this circuit is made possi-
ble by the divide -by-ten operation of the
7490. The 7490 simply counts input
pulses from the 555 until ten have been
received. It then produces an output
CATALOG flitlnlosh
pulse of its own. and FM DIRECTORY
It's possible to connect the divide -by- Get all the newest and latest information on the new McIntosh Sol-
id State equipment in the McIntosh catalog. In addition you will
ten output of the 7490 directly to an receive an FM station directory that covers all of North America.
elapsed -time indicator such as an LED
or audio oscillator. A better approach,
however, is to connect a second 555
hooked up as a one -shot to the 7490. ^' lá 91

The one -shot is easy to adjust, and it will n:

turn on the elapsed -time indicator for a
fixed length of time. This is a handy fea-
ture if you want to use a bell or buzzer as
an elapsed time indicator since the sec-
ond 555 will trigger a quick burst of
sound instead of a continuous noise.
MX 113
Figure 4 shows how everything is con- FM /FM STEREO - AM TUNER AND PREAMPLIFIER
nected together. A single 556 takes the
McIntosh Laboratory, Inc.
place of the two 555 timers. One of the
East Side Station P.O. Box 96
inverters in a 7404 hex inverter comple-
ments the output signal from the 7490 to
provide the propel triggering potential. If
SEND Binghamton, N.Y. 13904
Dept. PE

you don't have a 7404 handy, use one of NAME

the gates in a 7400 quad NAND gate.
Connect the two inputs of one gate
TODAY! ADDRESS
CITY STATE ZIP
together to form the inverter's input. (For
example, connect pins 1 and 2 of the If you are in a hurry for your catalog please send the coupon to McIntosh.

7400 to pin 11 of the 7490. Connect pin For non rush service send the Reader Service Card to the magazine.
CIRCLE NO. 26 ON FREE INFORMATION CARO
3 of the 7400 to pin 8 of the 556. Con
nett pins 14 and 7 of the 7400 to the
BUILD YOUR OWN Sporting Events Are An Experience As Exciting
positive and ground connections, re- as Being There!
Movies Are Seen The Way They Were Meant
spectively.) To Be Seen!
Pony And Other Video Games Are.More Exciting
The extra long timer circuit has sever- Than Ever!
al features you'll want to tinker with. Can Be Used With Video Tape
YOU ASKED FOR IT! Playback Equipment!
First, note that potentiometer R1 sets THE NEW LIFESCREEN II
the delay time while potentiometer R3 WE HAVE RECEIVED THOUSANDS OF INQUIRIES!
YOU REQUESTED PLANS FOR A BIG SCREEN TV THAT WOULD:
sets the on time of the elapsed time in- utilize any portable TV as an image source require a minimum of floor space -
dicator. used an LED for the elapsed -
I -be a beautiful piece of furniture.
time indicator in the prototype circuit, but NOW - EXTRON IS HAPPY TO ANNOUNCE THE ORIGINAL
LIFESCREEN I

you can use a relay if you prefer (Radio THE NEW LIFESCREEN H
Shack 275 -004 or equivalent). The LIFESCREEN was designed for the Do.lt.Younelf enthusiast who wishes to
have the enjoyment and excitement of a professional Big Screen TV but refuses -
Second, note that the 7490 has four to pay the $1500 to $4000 that most manufacturers charge for this luxury.
FACTS
outputs. Both pins 11 and 8 will provide The special LIFESCREEN Lens and Front Surface mirror supplied by Extron
are the same type used by major Big Screen TV manufacturers (Sony, Muntz,
a time delay ten times that of the first etc.). THESE PROFESSIONAL COMPONENTS SHOULD NOT BE CONFUSED
WITH THE CHEAP PLASTIC MAGNIFYING IMITATIONS NOW FLOODING
555 (one pulse out for every ten pulses THE MARKET BECAUSE OF THE POPULARITY OF BIG SCREEN TV.
The EXTRON TV Screen -
Me same used by the major Big Screen TV manufac.
in). Pin 9 will provide a time delay five furors -
is 16 TIMES BRIGHTER than a flat mane surface and 6 TIMES
BRIGHTER than most flat beaded movie screens. Its parabolic shape rejects
times that from the 555. And pin 12 will extraneous light, concentrating a highly efficient and directionally selective
television image that is exceptionally sharp and colorful.

provide twice the delay available from COMPLETE LIFESCREEN II

PACKAGE
COMPLETE LIFESCREEN
,"
I

PACKAGE: The INDEPENDENT projection system

that can be used with ANY SIZE screen
the 555.
Finally, if you want really long delays,
The SELF -CONTAINED internal projection
TV Plat will utilize any transistor portable TV
(12" to 19 ") ...
requires only 2 s 4 feet of
$299 usaul
1O p11si° °sli
rn,I,.d,d
up to 80" Diagonal
269
one of the many
reasons for its tremendous success.
COMPONENT LIST
Boos space -
fits neatly against any wall .
T

THE EVERYTHING GUARANTEE

I set of LIFESCREEN I Plans
you might consider connecting one or Mends its beauty to the decor of any room. ! Sharp 13" Model 13.421 Color TV or
Sony IS "Model K I541R Color TV.
EXTRON GUARANTEES EVERYTHING: THE PROFESSIONAL
COMPONENT LIST
more additional 7490 decade counters 1 setof LIFESCREEN 11 Plans
QUALITY, ACCURACY OF DESCRIPTION, AVAILABILITY AND I LIFESCREEN Lens
I LIFESCREEN Front Surface Mirror.
1 Portable transistor Color TV (12" to /9"1 PROMPT DELIVERY OF COMPONENTS DESCRIBED IN THISAD. R"x lo"
in series with the first. Just connect pin l LIFESCREEN Lens If, after building your LIFESCREEN PROJECTION SYSTEM, you 1 EXTRON LS 50 Screen 32'x40750"
2 IIFESCREEN Front Surface Minors: one are not satisfied for any reason, return all components to EXTRON, Diagonal.
11 of the first 7490 to pin 14 of the sec- 6"x10" and one 14;; "x 20 ". 8831 Sunset Boulevard, West Hollywood, California for instant LARGER
SCREENS can be ordered
I EXTRON LS 50 Screen, 32 "x40750" May refund of the purchase price. through EXTRON 167" or 80" Dime./
ond 7490. Pin 11 of the second 7490
PLEASE RUSH ME ONE COMPLETE SET OF LIFESCREEN PLANS io S9.00 EXTRON LIFESCREENry PROJECTION SYSTEM
goes to still another 7490 or to the in- PLEASE RUSH ME ONE COMPLETE SET OF LIFESCREEN II PLANS
1

@ 59.00 8831 Sunset Boulevard,

verter. Incidentally, note that this circuit PLEASE ALSO SEND ME THE ITEMS CHECKED BELOW: West Hollywood, California 90069

LIFESCREEN LENS @5150.00 Name

is a repetitive, free-running timer. In oth- LIFESCREEN FRONT SURFACE MIRROR, 8" x 10" @ 520.00 Address
LIFESCREEN FRONT SURFACE MIRROR, 145" x 20"
er words, it begins a new timing cycle El
EXTRON LS 50 SCREEN 32" x 40"¡50" Diagonal
@530.00
@590.00
City State Zip

immediately upon completion of the first. COMPLETE LIFESCREEN I PACKAGE a $269.00

CARD NAME
_ COMPLETE LIFESCREEN li PACKAGE @ $299.00 CARD NUMBER EXPR DATE
Keep this in mind if you decide to tinker Alt Prices F.O.B. factory -CM.. rasideuts add 6% sales tax. TOTAL: f NFO PAK - SISc
with super -long time delays.

JULY 1977 CIRCLE NO. 18 ON FREE INFORMATION CARD

83
Hobby Scene/
TVI AND CB TRANSCEIVERS

Q. I have a TVI problem whenever I

use my CB transceiver. My neighbors
get very upset and tell me to turn off
the radio. 15 there anything I can do
without going off the air? -Dwayne
Edwards, Canton, NY.

By John McVeigh A. If your CB transceiver is a fairly re-

cent vintage, type accepted, and used
properly, it should not be generating
STATIC CRASHES A. Offhand, I think the effective re- TVI. Often, tie interference is the result
Q. Please advise how to eliminate un- sistance is zero ohms. There is an infi- of overload within the TV receiver in the
bearable noise that my school's heat- nite number of resistors in parallel, and oresence of a strong 27 -MHz signal.
ing system produces on my Haiti- The way to identify overloading is to de-
crafters SX62A shortwave receiver. A termine the extent of the interference at
line filter was tried to no avail. The the TV receiver. If TVI occurs on all
most deafening noise is heard for two channels, receiver overloading is the
or three seconds between 5 and 18 culprit. Visual interference can range
MHz. -Gerard Richard, Sherbrooke, from fine cross- hatching to a completely
Quebec, Canada. dark screen. When the sound portion of
the program is also subject to interfer-
A. It sounds like a thermostat or thermo- ence, overloading is taking place.
stat- controlled power relay is arcing and The cure tor this problem is to prevent
generating r -f crashes. If you can "sniff the CB signal from reaching the TV. This
out" the source with a small field - can usually De done by attaching a high -
strength meter or even a portable radio pass filter such as the Drake TV- 300 -HP
(the static should also affect the AM (for twinlead) or TV-75 -HP (for RG -59 -U
broadcast band), try placing a suitable coax) at the antenna terminals on the
bypass capacitor across the arcing ther- back of the receiver. In some cases, the
mostat or relay contacts. A 0.1 -p.F, even though the further away from A filter will have to be installed at the tuner
1000 -V ac disc ceramic capacitor should and B the more series resistors you input inside the receiver's enclosure.
squelch the r -f. If you can't locate the have in each parallel combination, it When the CB signal is really strong, the
source, try the "Ear Saver" circuit shown looks like the resistance will go to zero. use of the hgh -pass filter might have to
in the Hobby Scene column on p. 34 of The only other solution could possibly
I be supplemented by more effectively
the January 1977 issue. see is a finite limit in the parallel combi- shielding the receiver. Fine copper or
nations. But my tendency is to say zero brass screening or flashing carefully in-
RESISTOR QUIZ ohms. Actually, the effective resistance stalled (beware of accidental shorts!)
Q. Here's a problem which was posed of an ever -increasing number of parallel can be installed on the inside of the TV
by one of my professors. You have an resistors will approach zero ohms, but enclosure aid grounded.
infinite lattice of 1-ohm resistors as will never reach it -just like the graph of When visual interference occurs only
shown in the diagram. What's the ef- a hyperbola or an exponentially decay- on TV channels harmonically related to
fective resistance between points A ing function. If any reader comes up with the 27 -MHz Citizens Band (principally
and B?-Bryan Baker, Houston, TX. different solution, feel free to send it in! Channel 2 at 54 MHz and Channel 5 at
81 MHz), the transceiver is radiating un-
rent limiting resistor, and a photocell. Of desired signals. This can occur when
TRIGGERING THYRISTORS
course, you can make your own op- the transceiver circuitry is improperly ad-
Q. I would like to control 120 -volt ac toisolator by enclosing the LED and CdS justed or operated. Over -modulation
devices with TTL logic without using cell in a light -tight box. Connect the op- from "power mikes" is a common cause
relays. Is there a way to do this using toisolator as shown in the figure. An ex- of harmonic radiation. Don't overmodu-
triacs or SCR's? They would only
have to handle 1 or 2 amperes.
Dominick Testa, Skokie, IL.
- ternal current limiting resistor may be
needed to keep the thyristor's gate cur-
late the trarsceiver and don't use a pow-
er amplifier. If the harmonic suppression
rent to a safe value. This depends on the of the transceiver must be improved, in-
A. The easiest way to trigger an SCR or lit resistance of the CdS cell. Using a sert a low-pass filter in the coax trans-
triac from a TTL output is to use an op- 10,000 -ohm, /4- or 1/2-watt series resis-
1 mission line close to the transceiver. Be
toisolator. It is essentially a LED, a cur- tor will limit gate current to 17 mA peak. sure you use a filter with a cut -off fre-
120VAC
quency around 40 MHz and attenuation
of at least 60 dB at TV frequencies
+5V
(Drake TV -42 -LP or equivalent).

L
TIL -32
LED CdS CELL
J
o LOAD
Have a problem or question on circuitry, compo-
nents, parts aailability, etc? Send it to the Hobby
Scene Editor. POPULAR ELECTRONICS, One Park
Ave., New YorK, N.Y. 10016. Thou 9 h all letters can't
be answered individually, those with wide interest
will be published.

84 POPULAR ELECTRONICS
 around an IC microphone amplifier.
Transmit /receive transfer is conducted

Product electronically.
It is interesting to note that the 29XLR
utilizes ferrite beads at strategic points
in place of wire -wound r -f chokes. These

Test Reports beads slip over a lead of the circuit to be

isolated or stabilized. The beads save
space, hold down circuit resistance,
minimize resonance effects, and are
highly effective in comparison to the
wire -wound chokes.
COBRA MODEL 29XLR MOBILE 40-CHANNEL
CB TRANSCEIVER Test Results. Receiver sensitivity of
Digital readout AM rig provides strong transmission punch. the Cobra 29XLR measured 0.5 µV
(with 30% modulation at 1000 Hz). Im-
age and i -f signal rejection measured 80
dB minimum, while spurious response
rejection of signals near the CB range
was 45 dB. Adjacent -channel rejection
and desensitization were nominally 60
dB. The overall 6 -dB audio response
was 240 to 2400 Hz. The maximum
sine -wave output power measured 2.75
watts at 3% THD at 1000 Hz into 8 ohms
at the onset of clipping. It measured 3
watts in the PA mode.
The agc held the audio output to with-
YNASCAN's Cobra Model 29XLR signal is set up by combining the output in 10 dB with a 26-dB r-f input change at
is a handsome 40- channel AM CB of the vco with a 36,570 -kHz crystal sig- 0.5 to 10 µV and to 13 dB with an 80 -dB
mobile transceiver that uses digital fre- nal at a "down" converter (mixer). The input change at 1 to 10,000 V. A nomi-
quency synthesis and a red LED numer- difference frequencies are extracted and nal 50 -µV signal registered S9 on the
ic display for channel identification. It in- go to an IC divider that is controlled by signal meter. The threshold range of the
corporates such features as: display the channel -selector switch. squelch circuit was 0.3 to 10,000 .V.
dimmer control, illuminated S /r -f/rela- Inductively coupled circuits at the in- The transmitter put out a 4 -watt carrier
tive -power meter, LED transmit /modula- put of the r-f amplifier and output of the with operation from a 13.8 -volt dc
tion indicator, microphone and r -f gain second mixer, along with a bandpass- source. The modulation capabilities ran
controls, and switchable noise blanker coupled circuit between the mixers, aid up to 100 %. With the microphone input
(NB) and automatic noise limiter (anl). In in good image and unwanted -signal re- level raised 25 dB above the level re-
addition, the transceiver has audio, jection. This is augmented by a 10,695 - quired for 50% modulation, the THD was
squelch, and Delta tune controls; PA fa- kHz ceramic filter after the first mixer. 7% at 1000 Hz, and the modulation held
cilities; external-speaker jacks; automat- The 455 -kHz selectivity is also obtained to just within the legal limit. The THD
ic modulation control (amc); detachable with a ceramic filter. with a 400 -Hz test tone was noticeably
dynamic microphone; bottom -facing Two i-f stages are followed by a diode greater in both waveform observation
speaker; line filter; and reverse -polarity detector and agc, the switchable anl, and measurement, the latter varying be-
protection. Operation is from a nominal squelch system, and an IC audio sec- tween 10% and 20 %, depending on the
13.8 -volt dc source with negative or pos- tion. The noise blanker employs an IC r -f level of the amc.
itive ground. amplifier /detector and three pulse am- We obtained high average modulation
The transceiver measures 91"W x plifiers for gating the output of the sec- with voice inputs without overmodulation
71/4"D x 21/4'H (24 x 18.5 x 5.6 cm). ond mixer. Electronic voltage regulation or adverse splatter. With voice input or
Suggested list price is $229.95. is supplied for all critical circuits. 1000 -Hz tone, the splatter at ±5000 Hz
The transmitter combines the output from the carrier frequency was at least
Technical Details. The receiver em- of the vco with a 10,695 -kHz crystal os- 60 dB down. Using a 2500 -Hz tone in-
ploys double conversion, with frequency cillator signal, using the difference fre- put, it was 50 to 55 dB down. The overall
control provided by a phase -locked -loop quencies, at a dual -gate MOSFET trans- 6 -dB audio response of the transmitter
(PLL) frequency synthesis system. A mitter mixer that is followed by band - was 400 to 2300 Hz. R -f frequency toler-
10,695 -kHz first i -f is obtained by hetero- pass coupling and the usual r -f stages. ance on any channel was within ±3 Hz
dyning the CB signal with the PLL's volt- The multi- section output network in- of -110 Hz.
age- controlled oscillator (vco) signal in cludes a TVI trap. The SWR bridge is a
the range of 37,660 to 38,100 kHz. The trough -line type. The collectors of the User Comment. This is a smartly
second conversion is to a 455 -kHz i-f driver and power amplifier stages are styled mobile transceiver, set in a black
with a 10,240-kHz crystal oscillator, from modulated by the receiver's audio out case with brushed silver -colored front
which a 10 -kHz standard reference for put stage, providing the customary high - panel and chrome -trimmed knobs. The
the PLL system is also derived through and low -level class -B modulation. Amc control knobs are located in a row along
dividers. The 10 -kHz vco comparison is obtained with a bootstrap setup the lower half of the front panel.
JULY 1977 85
 Our one complaint about the control in the PA function. Hence, instead of ity in our on- the -road tests. It should be
sequence arrangement is that the DYNA having the numeric readout display the noted that the microphone must be
MIKE (microphone gain) control is locat- letters PA, as is generally the case, the plugged into its connector to permit the
ed at the far left of the panel, where we meter's light extinguishes to indicate speaker to function.
automatically reach for the more-often that the transceiver is in the PA mode. On- the -air, we obtained a hefty punch
used VOLUME control. We determined that, when the trans- from the amc system, which prevented
The channel selector control knob has mitter is working into a nonreactive 50- overmodulation even when the micro-
a bar grip that makes it easy to manipu- ohm load (representing a 1:1 SWR), the phone gain was fully advanced. We ex-
late. Other switching functions are han- actual r -f output was accurately indicat- perimented with the DYNA MIKE control
dled by miniature toggle switches locat- ed at any point on the meter's SWR to determine its best setting. The clean-
ed in a line across the top of the front scale. (This does not necessarily hold est sounding signal was obtained with
panel between the meter and numeric true for other loads or high SWR's.) the mike gain reduced to the point where
display. Two of these switches have Use of the noise blanker allowed the MOD indicator blinked only occasion-
three positions that do not have much readability of weak signals in the pres- ally. At this point, we still obtained a high
lever swing, which sometimes makes it ence of high impulse noise from our im- average modulation level without sacri-
difficult to stop at the center position. A pulse -noise generator. It was similarly ficing intelligibility.
two-position Switch, H.F. /OFF, switches effective on ignition noise in a vehicle, The excellent performance of the Co-
in and out a "hash" filter that is a fixed - where it almost entirely eliminated the bra 29XLR transceiver far outweighs the
setting tone control that drops the upper noise (with a slight loss in signal level). minor criticisms noted here. It provides
frequency response to minimize high - The and also performed well. high sensitivity and fine selectivity, has a
pitched noises. Although the speaker in this transceiv- good transmitted signal without adverse
The edgewise meter is easier to read er is bottom facing, its sound reproduc- splatter, and possesses effective noise -
than most other similar meters we have tion is clean and crisp without the usual handling capabilities.
encountered. It is illuminated whenever muddyness associated with bottom -fac-
the transceiver is turned on except when ing speakers. It provided good readabil- CIRCLE NO. 104 ON FREE INFORMATION CARD

WAHL MODELS 7700 AND 7800 CORDLESS SOLDERING IRONS

Battery-powered irons with recharging stands.

It was not that a fully charged iron pro- power -on pushbutton switch. The button
vided just 100 to 150 soldered joints, but is rotatable so that its index can be set to
that it required up to 14 hours to re- either of twc positions. To use the iron,
charge to full capacity. Now, however, the index mist be set to the USE position
there are "fast- charge" cordless solder- before it can be depressed. Only in this
ing irons, as examined here. position can the button be depressed far
The two fast-charge soldering irons enough to close the switch contacts and
from Wahl are the Iso -Tip Quick allow power to be applied to the tip.
Charge" Model 7700 that requires about Whenever the iron is not in use, the but-
four hours to recharge and the Iso -Tip ton is rotated until the index is pointing to
60 Model 7800 that comes up to full the LOCK legend molded into the iron's
charge in about 60 minutes. Both irons housing. When the button is in the LOCK
come with their own recharger stand. position, the iron cannot be accidentally
The Model 7700 retails for $24.95, the turned on, which is a good safety feature
Model 7800 for $34.95. Available as an on a bench or in a crowded toolbox.
option is the Model 6500 ($10.95) print- The major improvement in the new
ed circuit board drilling attachment that irons is the fast -charging feature. The
fits all Wahl cordless soldering irons. Model 7700 iron's average four -hour re-
charging cycle is roughly a third of that
General Description. Tne two sol- required by the original Wahl iron. For
dering irons feature a couple of improve- just $10 more, the Model 7800 cuts the
ments that were not part of the original recharging time of the original iron to
Wahl cordless soldering iron we tested less than a tenth. Needless to say, with
1.40 -Tip Quick- Charge Model 7700.
five years ago. The first is that the head- either iron, you can make many times
When electrically powered cordless er has been redesigned to hold tips firm- more solder joints in a workday than was
soldering irons first appeared, we ly in place by friction instead of with the possible before. Hence, you can tackle a
lauded them because they gave us free- tiny Allen -type setscrews used on the fairly large project or kit -building job
dom from the ac line. Especially useful original iron. This makes installation and without resorting to a line- powered iron.
in the field, they also proved to be very removal of tips a simple plug -in /pull -out Special nickel -cadium cells are used
practical on our workbench. We did, operation. Of course, the tip can still be in the new irons. These cells, plus the
however, observe one shortcoming -we semi -permanently fixed to the header by newly designed charger stands, are re-
could not use the cordless iron for major loosening the header screws, inserting sponsible for the new fast -charge rates.
project and kit building that required the tip, and retightening the screws. In addition, the Model 7800 is equipped
hundreds of connections to be soldered. The second improvement is in the with a thermostat that automatically re-

86 POPULAR ELECTRONICS
 duces the full fast-charge rate to a safe us to assemble completely the I/O port
"trickle" once the cells have come up to in three one -hour stints. Needless to
full charge. When the cells are fully say, we were favorably impressed by
charged, and as long as the iron is still in the performance we obtained from both
its stand, a LED near the power switch irons, particularly the Model 7800.
comes on to indicate the full-charge sta- In our final test, we used the irons to
tus. A RESET switch on the left side of operate the optional pc -board drilling at-
the iron must be pushed down to allow tachment. The attachment itself accepts
the iron to charge at the fast rate again. a single size (No. 56) drill bit, which is
Both irons are equipped with screw -in good for just about all component -lead
lamps that illuminate the work area near and IC -pin holes. The attachment snaps
the tip when the power button is onto the tip- header end of the irons and
pressed. Also, both come with two tips, snaps into place on the newer irons or is
one a standard chisel and the other a held in place by a small screw on the
fine configuration for IC soldering. older Wahl irons. During our tests, the
The new irons are equivalent to 50- high -speed drill effortlessly drilled holes
watt line- powered soldering irons. The through paper -phenolic, polyester, and
tips come up to soldering temperature epoxy -fiberglass boards, both clad and
within about five seconds after the pow- unclad, with great accuracy and at a
er button is pressed, and each iron is high -volume rate. We did not attempt to
rated to deliver approximately 160 twist- run down the power packs in the irons
ed -tail solder connections, using 22- with the drilling attachment because, af-
gauge wire, from full charge. ter drilling several hundred holes in each
case, the irons were still going strong.
User Comment. The first test we per- Using the irons in both field service
formed on these new soldering irons work and on our bench, we found no
was to fully charge them from the corn - faults in their performance. They are
pletely discharged states in which they nicely contoured and light enough in
arrived. The Model 7700 took almost ex- Iso -Tip 60 Model 7800. weight to eliminate user fatigue. The
actly four hours to come up to full built -in lamps accurately illuminate the
charge, the Model 7800 about 50 min- which required several hundred connec- work area and are very convenient when
utes. Both irons became warm to the tions to be made. We found that intermit- working in chassis with deep recesses.
touch, especially the Model 7800, which tent operation of the Model 7800 iron, Also, the tips came up to operating tem-
was quite warm when the full-charge replacing it in its charging stand when- perature almost immediately.
LED came on. ever it was not being used to solder a In all, we consider either Wahl quick -
Our next test was to determine connection, allowed us to complete the charge cordless soldering iron an excel-
approximately how many solder joints entire memory board in two four-hour lent tool for any hobbyist's workbench,
each iron would deliver from full charge. stints, which is about the amount of time the choice dictated by the amount of
To do this, we did not replace the irons one would normally spend on a project continuous soldering time generally
in their respective stands between sol- even with a line- powered iron. The Mod- needed. We also highly recommend the
der operations as recommended by el 7700 iron provided enough soldering drilling attachment.
Wahl. We performed this test three power in intermittent operation to allow CIRCLE NO. 105 ON FREE INFORMATION CARD

times each for twisted -tail, solder -lug,

and pc-board connections with both the
chisel and fine points installed, recharg-
ing fully after each run. We obtained av-
erages of 187 joints for 22 -gauge twist-
ed -tail wire connections, 131 for solder -
lug connections, and 217 pc -board con-
nections with the fine tip installed. Using
the more massive chisel tip, the counts
averaged 152, 114, and 180 connec-
tions, respectively. The averages were
about the same for both irons.
As we were performing our solder -
joint count test, we kept track of the
times required for recharging to full ca-
pacity. Though the charging times did
vary from charge to charge, they were
well within 10% of the four -hour and 60-
minute ratings specified by Wahl.
Our next test was to tackle two rather
large construction projects, one a 4 -k
computer memory board and the other a
computer I/O interface board, both of The Model 6500 pc drilling attachment fits all Wahl cordless irons.
JULY 1977 87
 the radio technology to mass produce
suitable transceivers at a price the per-
sonal user could afford. In fact, the
Class B service was abandoned be-
cause it had not found any practical per-

CB Scene sonal application.

However, the GMRS service is still
available and has now become a high -
quality, practical CB service for person-
al -use radio communications, although
By Ray Newhall, KWI6010
equipment cost is substantially higher
THE ANATOMY OF CBRS than Class D gear. The new 460 -MHz
police communications equipment oper-
LL OF US who have traveled the tification between strangers on "the ates on assigned frequencies very close
reen stamp with wheels on our CB party line." They also serve a somewhat to the 462/467 -MHz GMRS frequen-
rigs (driven on turnpikes with mobile CB paradoxical purpose of revealing much cies, and this equipment can be used. It
radios in our cars) know that CB makes of a CB'ers personality while concealing is now feasible to mass -produce solid -
driving safer, provides additional securi- his true identity. know several people
I state equipment to operate on uhf. On
ty in case of vehicle breakdown, and is who are making collections of the most GMRS you may operate up to 50 watts
fun to use. It keeps the driver awake and unusual handles they hear. Some of the input power and raise your antenna up
busy on the road and it makes the trip oddest ones are those "pairs" of han- to 200 fee: in height. Line -of -sight FM
seem shorter. But does its usefulness to dles used by a CB'er and his XYL or oth- transmission is most normally used. Re-
highway users account for the CB fever er members of his family. peaters and auto -patches are currently
that has spread throughout America? The CB "lingo" is also unique. Al- permitted, just as the Hams now use
Why have ten million people shelled -out though it is colorful and mystic to new- them on the 2 -meter band.
$100, $200, or $300 each for CB rigs comers, it is concise and descriptive to In the Chicago, Cleveland and Dallas
curing 1976? What prompted nearly a those familiar with it, serving a true com- areas, to name but a few, GMRS
million new CB license applications to munication need. Its use gives CB'ers "CBers" have banded together to set up
flood FCC offices during the single the feeling of belonging to a group, just community repeaters. They use 15 -watt
month of January 1977? as Hams are joined by their knowledge mobile units or 21/2-watt hand -held tran-
The sociologists who keep watch on of Morse code. In fact, it is sometimes sceivers to reach the repeaters for reli-
the habits of the public are eyeing the implied that one who doesn't bother to able rebroadcast to other stations as far
CB syndrome and believe it is more than learn the CB language is not too wel- as 25 to 4C miles away. In this way, they
a fad which will soon pass on. They con- come on the band. can contact their families or offices
sider that it may signal an entirely new The CB Radio Service as we see it to- through the repeater, or they can dial di-
shift in sociological behavior. One Co- day is a unique and useful "game" for rect landline calls to business associ-
lumbia University psychologist recently young and old alike, and it serves the ates by use of a touch -tone pad on the
remarked to an FCC assemblage that need of a mobile community. However, back of :heir mikes. Tone -encoded
the growth of CB may be one of the most it is far from the type of personal radio squelch circuits are said to work so well
healthy sociological events since the service the FCC had in mind when the that these FM transceivers will be ac-
demise of the telephone party-line. For Citizen's Band was first authorized. CB tivated only by those calls intended spe-
the first time in forty years there are ex- was originally conceived as a two -way cifically for them.
tensive personal "one -to-one" com- radio service for use by families and As a matter of fact, this columnist just
munications occurring between people small businesses. Until recent years, mailed a Form 400 for a GMRS license
who are total strangers. there were only a few channels for com- to the FCC this morning. have a stand-
I

Oddly enough, this new form of per- munications between different station li- ard CBRS AM unit in my car for use on
sonal communication we call CB has censees. As the CBRS has developed the road, but it is not too practical to call
characteristics which are distinctly differ- today, it is not too effective for its original my home :located in a densely populat-
ent from our more traditional communi- purpose in heavily populated areas. Yet, ed Eastern Seaboard area) unless I'm
cation forms. It is not "face -to- face" and the need for such a service still remains! rather close by. operate a small con-
I

'projects an aspect of anonymity. Opin- sulting service and I intend to use

ions exchanged through this media are GMRS, The Other CB Service. The GMRS radio to keep in touch with my
apt to be more candid and open in na- CBRS (formerly the Class D service) is customers from my car while am within
I

ture because there is no fear of "peer not the only personal radio service avail- 25 miles o' my home.
disapproval" or reprisal. It is a medium able to the general public. The General GMRS is not for everyone, but it does
in which the young and the old can com- Mobile Radio Service (GMRS), formerly meet the needs of those who want high -
municate on common grounds and with called Class A, was the first CB radio grade personal and business communi-
similar interests; a far cry from the tragi- service. It was authorized in the early cations. The cost is from two to five
cally common communication failures 1950s. Eight pairs of uhf frequencies times as much as the current prices of
which occur between parents and their were allocated above 460 MHz. The CBRS equipment; more if you hang on
teenaged children. Class B service authorized low-power all these accessories. But for many peo-
Most CB'ers have given a great deal mobile two -way radio in the same fre- ple it serves a practical purpose and in
of thought to the selection of their CB quency spectrum. Neither of these two many cases may eliminate the need for
handles. Handles serve a far greater CB services was used extensively be- telephone answering service or even a
purpose than to provide temporary iden- cause, until recently, we have not had secretary.
88 POPULAR ELECTRONICS
 ecuted. During execution, the assembler

Computer Bits will scan the source program and pro-

duce a listing file containing a copy of
the source program along with the octal
machine codes and an object file con-
taining only the machine codes.
The assembler may also flag some
statements as having errors. Common
errors that an assembler can catch in-
clude using non -existent instruction
By Hal Chamberlin mnemonics and undefined symbols.
ASSEMBLERS The latter is the case when a reference
is made to a symbolic address but an
ACCORDING to a recent magazine would otherwise be a minor addition. actual address is never assigned to the
urvey, one of the most popular ap- With symbolic names, the assembler symbol. These and other errors detect-
plications of personal computers is soft- can do all of the address shuffling when ed by the assembler are usually caused
ware development, or simply writing pro- the program is reassembled and the by typing mistakes. After editing the
grams. As anyone who has been bitten programmer need be concerned only source program to eliminate errors and
by the programming bug undoubtedly with the additions. The concept is analo- reassembly, the object program is ready
knows, each new program is always big- gous to solving an equation in general to be loaded into memory and executed.
ger and fancier than the last. Beyond a using symbols and algebra and then
certain point in program complexity, substituting actual values into the solu- Types of Assemblers. Although all
however, the use of an assembler pro- tion rather than solving the equation for assemblers perform basically the same
gram is almost mandatory to eliminate each set of values needed. function, there is considerable variety in
most of the drudgery associated with A third advantage is that the use of an the implementation and use details. Per-
hand coding in octal or hex. This is par- assembler tends to develop good pro- haps the most distinguishing character-
ticularly true when one wishes to make a gram documentation habits which adds istic is the number of scans or passes
"small improvement" to a hand- assem- to the value of a program. All assem- over the source code done by the as-
bled program which otherwise requires it blers allow the latter part of each state- sembler.
to be rewritten. ment to be used for comments. A well - A classical assembler makes two
written program has an English explana- passes over the source program. During
Functions of an Assembler. Using tion of what the machine instructions are the first pass, all symbol definitions are
an assembler in machine language pro- accomplishing as comments on nearly searched out and placed in a symbol ta-
gram development has three important every statement. A neat assembly listing ble maintained by the assembler. During
advantages over hand coding. First, an of a program is also much easier to re- the second pass, the mnemonics are
assembler allows the programmer to produce and read than hand scrawls on translated into their octal equivalents
use operation mnemonics such as coding sheets. Conversely, buying a and the listing file and object file are
"LDA" for the "load register A" operation machine language program without do- generated. The two passes are needed
rather than the octal code 072 (8080 mi- cumentation in the form of commented because a reference to a symbolic ad-
croprocessor). When looking at a pro- assembly listings is like buying electron- dress may occur in the program ahead
gram you wrote several weeks ago or ic equipment without a schematic. of the definition of the symbol. This is
one written by somebody else, the LDA Using the assembler program itself is called forward referencing. If the assem-
is much more meaningful than the 072, generally quite simple. First the assem- bler is to know what octal address to
which in turn makes the program easier bly language program which is called a substitute for the symbol, it will have to
to understand. source program is converted into ma- see the definition first.
The second and most important chine readable form. Such a form may Several attempts have been made at
advantage is that the addresses of sec- be ASCII characters on paper tape, au- one -pass assemblers and a couple of
tions of code and data items can be giv- dio or digital cassette records, floppy these are available on hobbyist sys-
en symbolic names and referred to by disk sector records, or even ASCII data tems. The advantage of a one -pass as-
name. Again, a name like TAXTAB used in memory depending on the system sembler is increased assembly speed
to refer to a table of tax rate data is more and assembler used. Usually some kind since the source file, which may be
meaningful than its address which might of program editor is used to aid in en- many thousands of characters in length,
be 005:120. The most important benefit tering and editing the source program. needs to be read only once. Often how-
of symbolic names comes when a pro- Next the assembler is loaded and ex- ever the one -pass assembler imposes
gram is changed for some reason. With
.MACRO
a hand -coded program, some of the ad- . MACRO DEFINITION FOR A DOUBLE PRECISION ADD FROM MEMORY
dresses used in the program would MACRO- INSTRUCTION
a
probably have to change as sections of ADDS THE CONTENTS OF $ADDR AND $ADDR+1 TO REGISTERS B AND
C WITH THE RESULT IN B AND C, CONDITION FLAGS UNAFFECTED
the program and data are shuffled
around to make room for additions. $LBL DPAD $ADDR DOUBLE PRECISION ADD PROTOTYPE

Then, every reference to addresses that PUSH H SAVE H AND L

were changed would also have to be LHLD $ADDR GET TWO BYTES TO ADD IN H AND L
Fig. 1. Example
DAD B ADD THEM TO B AND C
changed. The result is that, in a large MOV B,H COPY RESULT INTO B AND C of macro
program, a considerable number of MOV C,L
definition.
POP H RESTORE H AND
changes may be necessary for what MEND
L

JULY 1977 89
restrictions on program organization and bers and simple editing commands. same dummy argument in the LHLD in-
the free placement of symbols. This is When a RUN command is given, the struction as in the prototype. The
due to the "look ahead" problem men - program is quickly assembled directly .MEND signals the assembler that the
tioned earlier. Sometimes a one -pass into memory and executed. Program macro definition is complete. The defini-
assembler is "faked" by a two -pass one. size is limited since the source program tion is then saved by the assembler in a
In this case the source file is read for the ASCII text, symbol table, and object pro- special table in memory reserved for
first pass and then saved in memory for gram as well as the conversational as- that purpose.
the second pass which is invisible to the sembler program itself must all fit into Figure 2 shows the use of this macro-
user. The difficulty with this approach is memory at once. instruction in a program (octal). In this
that a large amount of memory is need- example all of the instructions generated
ed to assemble a reasonably large pro- Advanced Assembler Features. when the macro was expanded are
gram. As assembly language programming ex- shown on the listing with a preceding mi-
Occasionally a "three- pass" assem- perience increases, some of the more nus sign. Generally the assembler will
bler is seen. These are really two -pass sophisticated assembler features avail- have a command that would suppress
assemblers with the second pass split in able will be appreciated. Although these printing of these expansion instructions
two to accommodate a Teletype with features have been rare in hobbyist ori- if desired. With a good library of macro
built -in paper tape. These machines ented systems, the assemblers being definitions, assembly language pro-
cannot punch the object file at the same supplied with recently announced floppy gramming may become almost as easy
time as printing the listing file so a sepa- disk systems generally have most of as programming in a higher level lan-
rate pass is required for each function. them. guage.
A. conversational assembler is anoth- One such feature is macro -instruction Another advanced feature is called
er variation. Basically a combination of a capability. A macro -instruction (often ab- "relocatable object code" capability. An
simple text editor and a conventional as- breviated as "macro") is one that may assembler having this feature supplies
sembler, the conversational assembler generate many machine language in- additional information in the object file
is very convenient for experimentation structions when assembled. When writ- so that it may be later loaded into memo-
and testing of short programs and sub- ing a program, macro-instructions may ry anywhere desired completely auto-
routines. Operation of a conversational
EXAMPLE PROGRAM SEGMENT ILLUSTRATING USE OF DPAD MACRO
assembler is much like most BASIC lan-
guage systems. The program is typed in 001:100 116 MOV C,M LOAD ORIGINAL RAW VALUE (16 BITS)
line -by-line and edited using line num- 001:101 043 INX H
001:102 106 MOV B,M
001:103 DPAD CORR ADD IN CORRECTION FACTOR
001:103 345 - PUSH H SAVE H AND L
001:104 052 200 001 - LHLD CORR GET TWO BYTES TO ADD IN H AND L

001:107 011 - DAD B ADD THEM TO B AND C

001:110 1C4 MOV B,H COPY RESULT INTO B AND C

SPEAKER
001:111 115 - MOV C,L
001:112 341 - POP H RESTORE H AND L
001:113 160 MOV M,B UPDATE WITH CORRECTED VALUE
001:114 053 DCX H
001:115 1E1 MOV M,C

KITS. Fig. 2. Example of use of a macro-instruction.

be used just as if the microprocessor ac- matically without difficulty. A special re-
tually had them as real instructions in its locating loader must be used to interpret
repertoire. this extra information and load the object
Macros can be defined by the pro- file into memory. Not only are the ad-
grammer at the beginning of his pro- dresses of a jump, call, and direct ad-
I

gram according to his needs. Although dressing instructions changed, but ad-
exact details of macro definitions and dress constants and other location de-
usage differ among various assemblers, pendent symbolic references are
a typical macro definition is shown in changed. An additional feature of the re-
Fig. 1. The .MACRO on the first line al- locating loader allows several object
erts the assembler that a macro defini- files that were generated at different
tion follows rather than ordinary program times to be linked together into a single
Money- saving, multi -element stereo
instructions. The next line gives the coherent program with all calls and
speaker kits. Build them yourself to save up
to half the retail cost of comparable macro prototype which defires how the jumps between the separate "modules"
ready -built systems. And get great sound macro -instruction would look in a source properly adjusted. This feature greatly
in the bargain. program. The symbols preceded by dol- facilitates the use of subroutine libraries
Send us your name and address and lar marks are sometimes called "dummy without having to copy all of the source
well mail you our free 44-page catalog of arguments" because, when the macro- code into the program being developed
speaker kits, raw speakers. crossovers, instruction is actually expanded by the every time a subroutine from the library
enclosures and tips on design and con- assembler, they are effectively replaced is needed.
struction. Its practically a manual on by the actual symbols used in the mac- With this little bit of background, the
speaker building. ro- instruction. Following the prototype reader should be able to evaluate more
8
are the actual machine instructions that fully the assembly language program
would be generated when the macro- development facilities of a particular
Dep. PE-B 5500 95th N E Seattle. WA 98105
instruction is used. Note the use of the system.

90 POPULAR ELECTRONICS
HOBBYIST COMPUTER CLUBS
vN
COMPILED BY Popular Electronics
COMPUTING
(Additions to list published April 1977)
POWER Only $169.95

CALIFORNIA North Central Ohio Computer Club

Association for Educational Data Systems c/o Bill Hicks
618 Teakwood Court
c/o Dr. Jane D. Gawronski
Galion, OH
Dept. of Education
6401 Linda Vista Rd. OKLAHOMA
San Diego, CA 92111
Tulsa Computer Society
Inland Computer Society
P.O. Box 1133
c/o Tom Munnecke
Tulsa, OK 74101
P.O. Box 55052
Riverside, CA 92517 PENNSYLVANIA
Southern California Computer Society
Northeast Computer Association With
P.O. Box 54751
Los Angeles, CA 90054
834 Lawler Street
Philadelphia, PA
MOTOROLA'S EDUCATOR II
ILLINOIS St. Thomas District HS Computer Club MICROCOMPUTER HEP KIT
1025 Braddock Avenue Motorola M6800 Technology
SCCS 5063
c/o Roy Emerson
14904 S. Calis Ave.
Braddock, PA 15104
Wilkes College Computer Club
Test -as- you -build in easy steps
normally one evening assembly
-
Posen, IL 60469 c/o Eric Jansen, Math Dept. Completely self- contained with
Wilkes College
St. Louis Area Computer Club all parts, cabinet and instructional
Wilkes- Barre, PA 18703
c/o Lou Elkins manual
Box 1143, St. Louis, MO 63188 TEXAS Learn MPU theory and programming as
you build, and then get ready to expand
MASSACHUSETTS Panhandle Computer Society
your computing power with these new
c/o Tex Everett
Boston Computer Society accessory kits that will be coming soon-
2923 S. Spring
c/o Donald Bradley Video Display Card
Amarillo, TX 79103
123 Commonwealth Ave. Keyboard Kit
Boston, MA 02116
Theater Computer Users Group Module Card Rack and Power Supply
Theater Sources Inc.
Greater Boston Computer Users Group
4712 Northway Dr.
Memory Modules
c/o Steven Hain
Dallas, TX 75206
Application Programs on Cassettes
40 Wilshire Dr. (Door 2)
Sharon, MA 02067 VIRGINIA Also available...
MINNESOTA Roanoke Valley Computer Club MOTOROLA HEP EDUCATOR II

c/o Lee Yosafat

Minnesota Computer Society
2026 Wynmere Dr. S.W.
P.O. Box 35317
Minneapolis, MN 55435
Roanoke, VA POWER SUPPLYKIT

WISCONSIN
MISSOURI
Durant Club
St. Louis Area Computer Club
do Lou Elkins c/o James White
901 S. 12th Street
Box 1143, St. Louis, MO 63188
Watertown, WI 53094
NEBRASKA
CANADA
Mid -America Computer Hobbyists
do Lt. Tom Montreal Micro -68 Computer Club
Smith
2708 Calhoun St. Case Postale al Succor Sale
Bellevue, NB 68005 Montreal, Canada H4Y 1A2
Ottawa Computer Group
NEVADA P.O. Box 13218
Kanata, Ontario, K2K 1X4 5 V @ 1.0 Amps ---"4"11111111111111/
SCCS
Societe d'Informatique Amateur du Quebec Designed specifically for Educator II
Quentin C. West
Microcomputer Kit
15 Ballerina
Henderson, NV 89015
IRISCO du Quebec Inc.
376 du Roi, Suite 304
Quebec, Canada PQ 2W6
Complete Kit -all parts, cabinet
and construction manual
NEW JERSEY
ENGLAND Send today for more information about
SOCS Educator Il
do William Staatse Amateur Computer Club
7 Dordells Please print label clearly.
Box 947, McGuire AFB, NJ 08641
Basildon, Essex, England
NEW MEXICO
JAPAN
US Robotics Society NAME.
Japan Microcomputer Club
Box 26484, Albuquerque, NM
First Ohkura Building 4F 2 -1
NEW YORK Nihoubashi, Chuo-ku, ADDRESS:
Tokyo, Japan
Stony Brook Homebrew Computer Club
c/o Dr. Ludwig Braun MEXICO CITY
College of Eng. and Applied Science
Carlos de Leon
State University of New York
Avenue Chapultepec 318 -603 STATE ZIP
Stony Brook, NY 11794
Mexico 7, DF, Mexico
OHIO
Dayton Microcomputer Association Ifyour club was not listed in the previous, or this
MOTOROLA
Semiconductor Products Inc.
Dayton Museum of Natural History coverage, please inform "Computer Bits," POPU-
2629 Ridge Avenue HEP /MRO OPERATIONS
Dayton, OH 45414
LAR ELECTRONICS, One Park Ave., New York,
N.Y. 10016.
705 West 22nd Street -Tempe, AZ. 85282 J
JULY 1977 91
 DESOLDERING BRAID PC DRILLING GUIDE

An inexpensive source of desoldering "wick" Here's a handy guide for drilling IC pin
is the outer conductor of RG -58 and RG -59 holes on a pc board. Epoxy a length of
coaxial cable. Cut your scrap into 8- to 10-
discarded Molex Soldercon holder strip
inch (20.4- to 25.4 -cm) lengths. Hold the
to a block of wood as shown. Attach a
braid and inner conductor firmly with pliers,
and pull off the outer insulating jacket with few strips o' double -faced adhesive tape
(Scotch Nc. 666 or equivalent) to the
Tips &Techniques your free hand. Then, push the two ends of
the braid together to loosen it, and pull out the
inner conductor and surrounding insula-
tion.-Arnold Irvine, Coopers burg, PA.
BLOWN -FUSE INDICATOR

This simple circuit will enable you to tell TEST JACK ADAPTER

at a glance whether you have blown a Have you ever bought a new meter or other
fuse-without removing the fuse from its piece of test equipment only to discover that
holder. As long as the fuse is good, no none of your standard 3/4 -inch spaced test
plugs wi'iI fit the jacks on it? If you can't or
ri

4RIK
NE-2 don't want to modify your new piece of gear
by slotting the test jack mounting holes, con-
sider this simple adapter you can make to
rectify the situation. All you need are a pair of
117V banana jacks, a pair of noninsulated banana
AC POWER LOAD
SWITCH jacks, and a 11/4-inch (3.81 -cm) square piece bottom of tie block to prevent slippage.
of '/s -inch (3.2 -mm) thick plexiglass or bake-
Hold the block on the pc board with one
lite. Round the corners of the plastic and drill
current will flow through R1 and 11, an hand and make indentations with an awl
two holes at opposite corners for the jacks,
NE -2 neon bulb. If the fuse blows, the ac
spaced 3/4 -inch (1.9-cm) apart. Then carefully
at each "valley" along the holder strip.
takes the alternate path through R1 and measure the spacing between the test jacks Then remove the block. You will find a
11. A 47,000 -ohm, 1/2-watt resistor is on the new equipment and drill holes for the line of depressions that can easily be
used to limit current through 11 to a safe plugs in the plastic square to match this spac- drilled thrcugh the board, exactly 0.1"
value. Mount 11 in any convenient (but ing. Assemble and wire the plugs and jacks (2.54 mm) apart. -Robert J. Murrell, Ve-
visible) location. -Ross Thompson, Lis- and you're all set. -Donald R. Hicke, San rona, PA.
towel!, Ontario, Can. Diego, CA.

IC SOLDERING AID

INEXPENSIVE ELECTRIC EYE To prevent heat or static damage to an

gate output to go high and the transistor
Here's an electric eye that can be built to conduct, energizing the bell. A 6 -volt integrated circuit while soldering, push
from junkbox parts. It consists of a CdS lantern battery can be used as a power the pins of the device through a few
photocell, a 7486 exclusive -OR gate IC, source. All parts can be obtained for sheets of aluminum foil measuring 2" x
an npn switching transistor (2N3055 or about $3 from a surplus house. A simple 2" (5.1 x 5.1 cm). Then mount the IC on
similar) and a small electric bell. When pc board is used, and can accommodate the circuit board. The foil will dissipate
no object interrupts the light path from a up to four independent circuits, each us- heat and electrically tie all the pins
lamp to photocell LDR1, both inputs to ing one gate in the quad ex-OR IC. The together. When the IC is in place, tear
the ex -OR gate are low. Thus the gate's entire alarm can be mounted on a TO -3 away the toil. Check carefully for stray
output is low and the transistor is cut off. heat sink. -Kenneth B. Blois, APO SF pieces of foil before powering the board.
Interrupting the light beam causes the 96286.
+V
The foil will generally come away in a
few pieces without leaving tiny scraps.
Aart M. Olsen, Newark, DE.
-
BIKE LIGHT SAVER
I installed a Soubitez alternator to power the
head and tail lights on my bicycle. Unfortu-
nately, found that the bulbs were burning out
I

ráther quickly when was travelling at speeds

I

greater than 15 mph. The problem was

solved by installing two zener diodes back -to-
back as shown in the figure. Before the modi-
fication, the alternator output was 6 volts rms
at speeds greater than 6 mph. After the
change, the voltage applied to the bulbs
dropped to about 4.9 volts rms. Bulb life was
considerably extended without significant re-
4 -V, 3 -W duction of light output. In the diagram, left,
ALTERNATOR
the miniatu-e headlight (/1) is rated at 6 volts
and 300 rrA. The tailight (12) is rated at 6
volts and 100 mA. The two zener diodes (D1
+V
I 3/4"-j and D2) a -e rated at 6 volts and 3 watts.
Higher -powered zeners can be used. -D.F.
O'Connell, Palo Alto, CA.
92 POPULAR ELECTRONICS
 Operation Assist
It you need information on outdated or rare
Rutherford B16R pulse generator, serial 171. Service
manual and /or schematic. Vilson Silveira, 7708 Regent Ave.
N., Brooklyn Park, MN 55443.

equipment -a schematic. parts list. etc -another reader Mariux 407 reel -to -reel recorder. Schematic, service manu-
might be able to assist Simply send a postcard to Opera- al, or any info. T.K. Flanagan, U.S. Bluefish (SSN 675) FPO
tion Assist. POPULAR ELECTRONICS. Park Ave New York.
1 .
NY 09501.
NY 10016 For those who can help readers. please re-

items regard: : egwpn'e

sources are ;_ ned
-
spond directly to them They Il appreciate ,t (Only those
troni normal
RCA Berkshire, circa 1948. Literature and data, also speak-
er. Fabris, 3626 Morne Dr., San Jose, CA 95127.

Transitorder TR300 reel -to-reel recorder. Need erase

and record head. Erase head has 230 -mH inductance, 1.5-V
dc erase, dc bias. Play- record head has 380-mH inductance,
0.2 V bias. Curt Palme, 990 Wavertree Rd., North Vancou-
American Scientific Development TV -20 tube tester. ver, B.C., Canada V7R 1S5.
Schematic, operating manual, chart. Will buy or copy. Terry
Nixon, RR 1, Box 182, Potosi, MO 63664. Heathkit
Sprague TO -3 capacitor checker. Need 15 -watt 50 -kohm
0-8 oscilloscope. Schematic and/or construction
manual. Frido W. Buschmann, 3736 Pine Rd., Huntingdon
Valley, PA 19006.
CITIZENS BAND
power rheostat. Ray Parsons Jr., Portsmouth Ave., Stra-
tham, NH 03885. Heathkit 0 -12 oscilloscope. Need power transformer.
HANDBOOK
Kenneth Huffines, 356 O'Brian Dr., Stone Mountain, GA The all -new 1977 edition, by the editors
Kris "Match Maker," serial 3302003. Schematic and /or 30088. of POPULAR ELECTRONICS, has all
specifications such as frequency, impedance, etc. Bob Dia-
netti, 80 Killington Rd., East Aurora, NY 14052. the authoritative information you need
Crosley 96 radio. Circa late 30's. Schematic, power trans-
former. Richard R. Nolette, RFD #1, River Rd., Kennebunk- on CB two -way radios to make an in-
AGS IC -RS-82 eight -track recorder /player. Schematic.
- port, ME 04046. telligent buying decision.
Henry D. Mikkelsen, VA Hospital, Marion, IL 62959. It features a
Mercury Electronics 1101 tube tester. Manuals, any in-
Gran Sonic GS-2 stereo receiver. Schematic, also need
power transformer, marked SAT -260 OCM. John D. Gill, Rte.
5, Box 370, Blountville, TN 37617.
formation. James B. Martin, 1708 Dave Dr., McAlester, OK
74501. COMPLETE
RCA WO-91B oscilloscope. Operating manual. Donald R.
Atwater Kent 35 radio, serial 772713. Date of production,
value. Kenneth J. Roberds, Box 367, Barling, AR 72923.
BUYING GUIDE
for the new 40- channel CB two -way
Anthony, 821 Lantana St., Corpus Christi, TX 78408.

Allied Knight
Transcom RCT 203 audio data terminal with strip printer. radios, antennas and accessories -
83Y102 Star Roamer radio. Schematic. Will Schematic and /or manual. Will pay for copying. J. Bryan fully described with technical speci-
buy or copy. Gerald Fox, Fox Electronics, Box 890, Rte. 3, Loofbourrow, Box 1237, Mountainside, NJ 07092. fications, features, latest prices and
New Holland, PA 17557.
photos. Other articles include the latest
Century VT -10 VTVM. Schemtaic, operating manual,
RCA WP -23A regulated power supply. Schematic, operat- probe. Eke 232 VTVM. Schematic, operating manual,
FCC Rules and Regulations changes
ing instructions, or service manual. Ronald Gillen, Box 383, probe. Supreme 542 multimeter. Schematic, operating in down -to -earth language How to in-
Hustisford, WI 53034. manual. Allen C. Fryou, 3735 Fairmont Dr., New Orleans, LA stall a CB mobile system -and save
70122. money How to operate and commu-
Cartrivision video tape recorder. Source of tapes and
nicate with your first CB rig Will sun-
spare parts. Donald Weber, 1333 N. Camino Alto, Apt. 245, Sharpe HA -10A or other Sharpe headphones. Source. Dr.
Valleyo, CA 94590. James P. Gaston, 45 East End Ave., Apt 5A, New York, NY spots affect CB range CB language
10028. translation chart How emergency CB
Bell & Howell 34 oscilloscope (DeVry Inst. of Tech.). Op- associations can save your life Manu-
erating manual, schematic. R. Wood, 465 San Antonio, Palo Precision 100 VOM. Simpson 311 VTVM. Schematics. facturers' specifications -"decoded" so
Alto, CA 94306. Alan Norville, Rte. #2, Box 283, Forest City, NC 28043. that you will be able to read a "spec
Hickok sheet" with ease and much more in-
640 oscilloscope. Schematic and /or service manu- Hallicrafter S -38 -E. Schematic, alignment manual, or any
al. Robert Zusman, 200 East Indian Spring Dr., Silver Spring, info. Steve L. Porter, 429 Balsam, Rogers City, MI 49779. formation packed into one volume, all
MD 20901. written by the experts.
Cenar 250 oscilloscope. Motorola FMTRU80D(A)1C2C
LLoyd TM -988 AM /FM receiver. Schematic, operating
manual and /or parts list. Peter B. Trippett, 581 Glen Rd.,
mobile 2 -meter transceiver. Schematics, operating manuals, 1977 CITIZENS BAND
any other info. David Eubank, Box 113, Greenup, IL 62428.
Sparta, NJ 07871. HANDBOOK GOES ON SALE
Skycrafter "VHF Superphone" AMT -9 transmitter, AMR-4
Friden paper -tape readers, typewriters, Justowriters. Sche- receiver. Schematics and any other info. Al Gwinn, 3321 NATIONALLY JULY, 1977
matics, operating instructions. J.I. Taylor, Box 289, Salem, Beverly Dr., Dallas, TX 75205.
MA 01970.
Radio Shack 28-138 color organ kit. Schematics, parts
RESERVE YOUR COPY NOW
General Radiotelephone MC -5 CB transceiver. Sche-
matic, manual. Elliott Electronics, RR 2, Box 61, Effingham,
list, or instruction manual. Gary Girzon, 4665 St. Kevin #3, AT THE SPECIAL
Montreal, P.Q. Canada H3W 1N8.
IL 62401. PRE -PUBLICATION PRICE
A.C. Cosser 1434 preamplifier. Source of 120 -V battery.
Tektronix 564 scope. Need 3B3 time base, 3A6 vertical A.C. Cosser 1049 MKII oscilloscope. Original camera, OF ONLY $1.50
plug -in. Ramesh B. Parikh, P.O. Box 17356, Bombay 400 CRT. Claude Houde, 7427 Boyer St., Montreal, P.O. H2R This offer is available to readers of
058, India. 2R9. POPULAR ELECTRONICS only. Regular
price is $1.95; mail order $2.50. Save money
Fisher 400 receiver. Schematic and /or information on pow- Olson AM- 240 50-watt amplifier. Output transformers, B- and enjoy the convenience of having the
Magnavox 9-295HH console. Schematic,
er transformer. ohm output impedance. W.B. Wells, 172 Topsfield Rd., Pitts-
1977 CITIZENS BAND HANDBOOK mailed
power capabilities of 15" woofers that come with console. burgh, PA 15241.
to you from first -off -the -press copies when
Thom Filippeli, Rte. 1, Box 39 -Z, Connie Lane, Shingle
Springs, CA 95682. Erie Pacific 720 frequency counter. Service manual, published. Complete the Reservation Form
schematic, parts list, source for Elesta EZ10A and Bur- and return it promptly with your remittance.
Radio City 488 multimeter, circa 1942. Schematic and any roughs 5031 tubes for counter. Gordon Wheatley, 9 Lynn -
other information. Joe H. Hibbs, 971 -87 Borden Rd., San grove Ave., Toronto, Ontario, Canada M8X 1 M3.
Marcos, CA 92069.
Collins 32V2 transmitter. Instruction manual. Marvin E.
Jackson Instrument 641 -A signal generator. Schematic, Weber, Box 1261, Alamogordo, NM 88310.
alignment procedure. J.M. Nightingale, 1675 Comox St., CITIZENS BAND HANDBOOK, PE -777
Vancouver, B.C. Canada V6G 1 P4. Realistic 212 preamplifier, 210 ultra- linear amplifier. Any Consumer Service Division,
info. R. A. Rouge, Box 92, Hollywood, CA 90028. 595 Broadway. New York. N.Y. 10012.
Dectronics SR -55 calculator. Owner's manual, source of Enclosed is $1.50 (outside U.S.A. $2.00)
case and keytops. Ivan Dzombak, 621 Spring St., Latrobe, U.S. Govt., RAO-2 Navy shortwave receiver (National type for the 1977 CITIZENS BAND HANDBOOK
PA 15650. NC-120), Navy CNA- 46187. Service manual and /or sche- to be mailed to me in July, 1977 when
matic. David L. Larson, 13011/2 S. First, Harlingen, TX 78550.
published.
Karr TR -505 uhf repeater. Schematic, owners manual or
any info. V.C. Reed Jr., 1104 Abbot Ln., Park Forest South, Precision EV10A VTVM. Schematic, manual. Willis J. Ball, Residents ofCA, CO, FL, IL, MI, MO, NY
IL 60466. 320 Bloxam Ave., London, Ontario, Canada N6J 3K6. STATE, DC and TX add applicable sales tax.

Solid State Devices Trigsweep, circa late 1960's, In- Crosley Showbox, circa early 1900's. Shematic, any re- Print Name
struction manual, pc artwork, parts list. John A. Harlan, 9720 building or service info. Kenneth Huffines, 356 O'Brian Dr.,
Prospect Ave., Chicago, IL 60643. Stone Mountain, GA 30088. Address_
Superior Instruments 707 or 707 -A VOM multifester. National SW-3 receiver. Need series 10-20 coils, band - City
Schematic, instruction manual, parts list. Buy or copy. Arthur spread if possible. Martin Edelheft, 245 -21 77 Crescent, Bel -
Kneller, 84 Bennett Ave., Neptune City, NJ 07753. lerose, NY 11426. State Zip
JULY 1977 93
Signal Corps BC -458 -A transmitter. Schematic and /or op- search Products Model 203 crystal checker. Schematic and EMC Model 600 oscilloscope and Model 400 signal genera-
erating manual. Dan Williams, Rte. 58, El Cerrito, CA 94530. any available information. Craig K. Sellen, Box 293, Carbon- tor. Schematics and instruction manuals. J. Massing, 208
dale, PA 18407. Dickens Dr., Toledo, OH 43607.
Heathkit W -3AM amplifier, with or without matching WA-
P2 preamplifier. Source. David Hayes, 35 Cotton St., Gan- Micronta Model 22 -012 tube tester. Need tube chart.
der. Nfld., Canada AI V 1E3. Charles A. Mizera, 3226 N. Kostner Ave., Chicago, IL 60641. Dumont Type 24'. oscillograph and Hickok Model RFO-5
oscillograph. Schematics and /or parts lists. A. Elliot, 221 N.
WW II Equipment. Model RDO (Navy issue) receiver (circa Clough -Brengle Model 111 frequency modulator. Opera- 4th St., Tonawanda, PA 18848.
1945); Model AN /SPR -2 receiver; Model AN /APA -6A oscil- tions manual or any available information. 3.J. Kulp, 1115 Li-
loscope. Schematics and general manuals. John Andrews Ill, lac Lane, West Lawn, PA 19609. Eico Model 221 VTVM. Meter needed Hervey C. Cain, Box
11011 Waycroft Way, Rockville, MD 20852. 66, Coal Hill, AR 72832.
Heathkit Model 1G-62 color bar arid dot generator. Sche-
Stephens "Truphonic" midrange speaker systems. Circuitry matic and /or service manual. Earl D. Kent, 810 E. 1st St., Zenith Model 65532 2 -band table radio. Operating manual,
anc parts information. Frank J. Burris, 35640 Avenue F, Yu- Emmett, ID 83617. schematic, parts and alignment information. A. Hawk, 21 Ri-
caipa, CA 92399. vercrest, Hanover, NH 03755.
Panasonic Model RF -1006M AM /FM /MB radio. Schematic
Bunker Ramo Model 203-B-MON teleregister video display. and operations manual. Bruce Stanley, 350 Beachwood RCA Model WT-1)0A electron -tube micromho- meter. Oper-
Schematics and /or service manual. F. Ascolillo, Park Lane, O.T.S., Granburg, TX 76048. ation manual, schematic and tube chart. Danny Tovar, 4700
North Windham, ME 04062. Rockmoor Ln, Foil Worth, TX 76116.
B &K Model 1075 television analyst; Model A107 Dyna-
Microsystems International DTMF receiver card. Schemat- Sweep circuit analyzer; Model 445 CRT tester. Service and Hallicrafter Model CN -1 FM converter. Schematic needed.
ics and manuals or any available information on touch-tone operation manuals. Paul S. Panikowski, 5006 Edgewood H.A. Wickert, 5 Deerview Ln, Asheville, NC 28804.
receiver cards. James Chochos, Jr., A -E 6107, San Luis Rd., College Park, MD 20740.
Obispo, CA 93409. Concert Compary Model 8003 "Emitator." Schematic and
Cartridge Television Inc. Model MCA -0001 video camera. parts list for sery ,cing. Bud Petersen, 801 Polynesian Dr.,
Philco Model 41 -608, Code 122 radio-phono combination. Schematic and service manual. Michael A. Uzzio, Apt. 8C, Long Beach, CA 90805.
Schematic, parts list, tubes and parts source. R. Galligan, Clover Path, Spring Hill Apts., Maple Shade, NJ 08052.
Box 326, Niantic, CT 06357. Canadian Marconi Model C-2 frequency indicator (circa
Reflector, 18 -in. parabolic. Need source. Albert Bhuatapher, 1943). Schematic and operating instructions. M. Armstrong,
Leak point -one stereo preamplifier and stereo-fifty power 5008 W. Pullerton Ave., Chicago, IL 60639. 243 Howard, Shermroo ke, P.Q., Canada.
amplifier. Altec Lansing Model 445A stereo preamplifier.
Schematics needed. Bill Rathyen, 19 Broadway, Bayonne, Jackson Model TVG -2 TV /FM sweep alignment generator. McMurdo Model 900 Silver Vomax. Schematic and operat-
N. 07002. Schematic and operation manual. Eden Rubin, 227 -12 57th ing manual. Don Nhite, 109 Burns Street, Essexville, Mich-
Ave., Bayside, NY 11364. igan 48732.
Simpson Model 330 tube checker. Schematics, operations
manual and current tube sheet. Duane Schuh, 824 La Porte Measurement Control Devices Model 300 oscilloscope. Miranda "Nocturne" stereo tape recorder. Schematic or any
Dr.. La Canada, CA 91011. Schematic and manual. Michael E. Headberg, 7760 NW 171 available information. Walter Baker, 162 N. Queens Ave., N.
St., Hialeah, FL 33015. Massapequa, NY 11758.
Meissner Analyst. Operating and service manual. John Gra-
ham, Box 186, Wurtsboro, NY 12790. Automatic Radio "Tom Boy" AM radio (circa late 1930's- Microsystems International touch-torte receiver. Manual
early 40's). Parts list and /or schematic. C. Walker, 131 Ber- and /or schematic J. Chochos, Box A -E 6107, San Luis Obis-
Superior Instruments Model 77 VTVM Schematic and /or nard St., San Francisco, CA 94109. po, CA 93409.
service manual. Mr. Test, P.O. Box 9064, Newark, NJ 07104.
Precise Model 305R triggered scope. Schematic, parts list McIntosh Model C-8 or C -8P. Looking for unit. B. Gerber,
Eldico Model MT 2 2 -meter
AM transmitter. Schematics and and instruction manual. William H. Bragg, 1424 College, Des 8221 Streamwood Dr., Ba Ho., MD 21208.
operations manual. Francis H. Bailey, 541 Hill P.O., Dudley, Moines, IA 50314.
MA 01570. Hallicrafters Model SX-100 receiver. Operator's manual,
Transcom Electronics Model SBT3 SSB transceiver. Align- schematic or other information. Dale C. Vawter, 117 Altena
Kepco Labs Model 150 rack -mount variable power supply. ment instructions, schematic and any other available infor- St., San Rafael, CA 94901.
Schematic, parts list and wiring diagram. Also, Crystal Re- mation. Ari Procopio, QSL Bureau, P.O. Box 22 Labre, Sao
Paulo SP 1000, Brazil. Racom Model 2174 -610 selective voltmeter. R. Reed, 2054

THE IINA 8700 Solid State Model ST -1000 TV camera. Any available infor-
mation. Leigh Klotz, Jr., 119 Harmony St., McComb, MS
39648.
Bradley, Ypsilanti. MI 48197.

Hartman "Hurricane" vhf -FM marine transceiver, 5-channel.

Circuit diagram and manual. Paul Smith, 65 West St., New
COMPUTER/ CONTROLLER Honeywell Model TCM -31-C memory. Need PAC card lay-
London, CT 0632).

An exceptional price on an out. Joe Schram, Box 1818 Washington, DC 20013 Dumont Type 322 dual -beam oscillograph. Service or sche-
matic. David Paseur, 6327 Everglades Dr., Alexandria, VA
applications oriented 6503 based Hallicrafter Model S38E shortwave receiver and Precision 22312.
micro -processor system Model E -200 signal generator. Need schematics. S. Bergen
Wilson, 1403 Lyttleton St., Camden, SC 29020. Military radio receiver Model R-440 (XN -1) manufactured by
RCA. Operating manual, service manual, schematics or any
Hammarlund Model FM50A outercom and Knightklt Cat. available information. Peter Z. Simpson, 18 University Dr.,
No. 83Y146 oscilloscope. Schematics and manuals. James Natick, MA 01760.
F. Reuter. 2595 Marlborough, Detroit, MI 48215.
Knight Model KG -2000 oscilloscope. Service and calibration
Radio Compass Type /ARN6 receiver control box.
11101 data, power transformer data, and /or source. Ron Hunter,
Handbook and RX mounting rack needed. Lionel L. Sharp, 308 Mertens Ave Racine, WI 53405.
,

19 Kelso St., Chermside, Queensland, Australia 4032.

APELCO Model AE -31MA radiotelephone, AMECO Model
American Concertons Model 505 reel -to -reel tape recorder. CMA multttand converter and B &K Model 500 "Dyna-Quik"
Schematic and service information. Duncan Crawford, 206 tube tester. Service manuals or any available information.
Cedarwood, Flushing, MI 48433. Herb. Mitschan, 1 688 Baywood Dr., Petaluma, CA 94952.

Rockland Model 5500 frequency synthesizer. Schematic Philco Model 41 -250 radio. Schematic, parts list and parts
needed. Thomas Barrett, 39 Lake Drive, Monroe, LA 71201. source. Charles M. Pacha, Box 208, Marysville, KS 66508.

Superior Instrument Model 800 allmeter. Schematic and Philco Model 19 MK II wireless set with Model 3A MK II con-
operating manual. Robert E. Heitz, 317 Woodward Ave., Buf- trol unit. Built fo- Russian tanks during W.W. lt. Need any
falo, NY 14214. available information. Cliff Holm, 1900 Grant Dr., Regina,
Sask., Canada.
Navy Surplus oscilloscope type TS- 34A /AP. Schematic and
THE IDEAL, LOW COST SOLUTION TO IMPLEMENTING service manual. James W. Booker, 2808 W. Boyce Ave., Fort Johnson "Viking Ranger I" transmitter and Drake Model 2B
Worth, TX 76133. receiver. Operation and service manuals. Paul Barbuto, Box
THOSE WILD COMPUTER BASED CONTROL SYSTEMS
385, Genesee, ID 83832.
YOU'VE BEEN DREAMING OF! Magnavox Model FM -16 AM /FM radio. Schematic. Robert J.
PAIA software currently available or under Hewitt, 318 N. Greenbay Rd., Waukegan, IL 60085. DeVry Tech. Model 1 -15 5 -inch oscilloscope. Builder's man-
development includes: Music synthesizer ual and calibration instructions. Andy Van Loenen 4684
interface; Home applications package including: Burroughs 9350-2 (Friden #7311) computer terminal key- Wakefield N.E., Comstock Park, MI 49321.
multi-zone fire/burglar alarm, real time clock, board/printer. Control unit schematic and maintenance
energy saving heat /air conditioning control, manual. Gary Alderman, 8615 Portsmouth Dr., Laurel, MD Muse sequencer oscillator, Western Electric Model TP25 -1
computer generated 'Hoor -bell ; Model roalroad 20811. amplifier and 3-M Model 78 -9020 microphone. Schematics
and parts source. James D. Craig, 511 Cedar St., Allentown,
controller and more Grundig Model M72 PX musical instrument. Schematic or PA 18102.
8700 COMPUTER /CONTROLLER KIT $149.95 tube list. Greg Binverse, 311 Monroe St., Valders, WI 54245.
(requires 5v. @ 1. 2A. ;12v. @ 150 ma, ) Crosley Model Super 11 radio. Schematic and any available
Shipped direct from PAIA (add $3. 00 postage) Advance Electronics Model OS 15 osciloscope.
Schematic information. David P. Lesser 82 Rolling Green, Amherst, MA
Also available at FULL LINE computer stores and any available information. Anil Rodrigues, Gilpin Ave., 01002.
#1, Wilmington, DE 19806.
DETAILS IN OUR FREE CATALOG
BM. DEPT. 7-P 1020 W. Wilshire Blvd.
Oklahoma City. OK 73116
Webster wire recorder Recording wire needed.
witz, 9 Henneberry Ln., Golf, IL 60029.
A. Marko-
Teletype Corp. Model 15Y typing unit. Schematic and in-
struction manua. Martin H. Bunshaft, 29A Forest Acres Dr.,
Bradford, MA 01830.
CIRCLE NO. 36 ON FREE INFORMATION CARD
94 POPULAR ELECTRONICS
 transceiver with digital readout, a 2 -kW 8877
linear amplifier, a 50 -MHz frequency counter,
and improved RFI filters. New amplifiers and
a mobile antenna for 220 MHz are featured.
An antenna coupler employing fixed capaci-
The
tors and a homemade variable inductor helps
beat the parts procurement problem.
Published by the American Radio Relay
"Click
Electronics Library League, Inc., 225 Main Street, Newington,
CT 06111. 704 pages. $12.50 hard cover
($13.50 in Canada, $14.50 elsewhere), $7.50
and Pap"
ELECTRONIC TROUBLESHOOTING WITH
SIMPLIFIED CIRCUIT ANALYSIS
by Leo Rozman
soft cover ($8.50 in Canada, $9.50 else-
where).
machine only by
ELECTRONICS ONE- SEVEN, VOLS. 1 AND 2
The author aims to familiarize the reader with
a wide variety of circuits, how they operate, These two volumes (one on electronics, one
and how to localize trouble using symptom on electricity) are revised second editions of
analysis, signal injection and /or tracing. Us- elementary self- teaching texts that first came
ing simple circuits (mostly solid- state) as ex- out ten years ago. Each features one topic or
amples, the author covers troubleshooting concept per page, with at least one illustra-
via dc and ac measurements, the effects of tion on every page. Coverage is thorough,
passive components, identifying circuits, con- and very little math is used. Each volume is
trols and adjustments, and symptom analy- made up of seven parts. The electronics vol-
sis. The stress is on practical, time -saving ume covers electronic signals, electronic
techniques in repairing radio and TV receiv- building blocks, electron tubes, semiconduc- Ever since the invention of the re-
ers. tors, power supplies, oscillators, and auxiliary corded disc annoying "clicks" and
Published by Parker Publishing Co., West circuits. The electricity text covers "producing "pops" caused by scratches, static
Nyack, NY 10994. 240 pages. $12.95 soft electricity," dc circuits, ac circuits, LCR cir- and imperfections have consistently
cover. cuits, test equipment, power sources, and disturbed the listening pleasure of
electric motors. music lovers.
Published by Hayden Book Co., 50 Essex
MODERN ELECTRONICS MATH St., Rochelle Park, NJ 07662. Electronics: Now, SAE introduces the unique model
by Jerrold R. Clifford and Martin Clifford 1,000 pages, $21.95. Electricity: 992 pages, 5000, an Impulse Noise Reduction
Immediate application is the keyword here, $20.85. Hard cover. System which eliminates those un-
with electronics first brought into the picture wanted sounds with no adverse effect
on page 21, in a problem on adding series re- on the quality of the recorded material.
sistance. Arithmetic, algebra and trigonome- TV TYPEWRITER COOKBOOK
This breakthrough in electronic cir-
try are thoroughly explored, with a multitude by Don Lancaster cuitry is so demonstrably effective
of examples taken from electronics. In the As the "subtitle" indicates, this is a "complete
that the SAE 5000 is destined to be-
section on square root, the reader is shown guide to low -cost television display of al-
come an essential part of any sound
how to calculate current, given power and re- phanumeric and graphic data for micro-
system.
sistance. In the chapter on trigonometry, processor systems, computer hobbyists, ham
phase angle and impedance calculations are RTTY, TV titling, word processing, and video The SAE 5000 is compact and sleek,
introduced, among many other areas. A games." The author, who has also written built to SAE's exacting standards, and
chapter on logarithms gets into decibels, other electronic "cookbooks," covers TV ready to enhance the performance of
power gain, etc. Four chapters are aimed at typewriters in depth: IC's for TVT use, memo- any system, from the standard receiv-
computer math: binary numbers, octal and ry, timing, cursor and update circuits, key- er /turntable combination, to the most
hex humbers, other number systems, and boards and encoders, serial and TV inter- sophisticated audiophile components.
Boolean algebra. faces, hard copy, and color graphics. Dozens
Published by Tab Books, Blue Ridge Summit, of schematics provide information for building SAE is proud to add the 5000 to their
PA 17214. 684 pages. $9.95 soft cover, one's own TVT, or serve as background broad line of Components for the
$12.95 hard cover. material for the hobbyist interested in know- Connoisseur.
ing what's inside the kit or wired TVT he's
bought.
THE RADIO AMATEUR'S HANDBOOK (54TH ED.) Published by Howard W. Sams & Co., 4300
by the ARRL Headquarters Staff W. 62 St., Indianapolis, IN 46206. 256 pages. Scientific Audio Electronics, Inc.
$9.95 soft cover. P.O. Box 60271, Terminal Annex
The 1977 edition of the radio amateur's "bi- Los Angeles, Cal. 90060
ble" has been revised to reflect changes in
both technology and amateur radio. An intro- Please send more information on the
ELECTRONIC SYSTEMS 5000.
ductory chapter explains the basic character-
istics of the amateur radio service, and is fol- THEORY AND APPLICATIONS

lowed by chapters dealing with radio theory. by Henry Zanger Name

The handbook is well illustrated and contains This text exphasizes how to use available
many graphs, formulae, and representative IC's rather than how to design circuits, so the Address
circuits. An expanded chapter on radio prop- stress is on the system. There are chapters
agation, a section on radio and boating, and a on system analysis, transducers, compo- City
frequency chart covering vlf to uhf are includ- nents, communications systems, instrumen-
ed. Among the new projects appearing in the tation, control systems, and reliability and State Zip
handbook are an 80 -to -10 -Meter solid -state maintainability. The hardware ranges from op PE-777
CIRCLE NO 43 ON FREE INFORMATION CARD
JULY 1977 95
 Put Professional Knowledge and a

COLLEGE DEGREE amps to plotters, the math from Laplace of binary and hexadecimal numbers; and
in your Electronics Career through transforms to transfer function analysis, in hexadecimal addition and multiplication ta-
this technical look at a wide range of sys- bles.
tems. Published by 3arland Publishing, Inc., 545
Published by Prentice -Hall, Englewood Cliffs, Madison Ave., New York, NY 10022. Hard
NJ 07632. 352 pages. $15.95 hard cover. cover. 171 pages. $12.50.

SEMICONDUCTOR REFERENCE HANDBOOK

COLOR TELEVISION TROUBLESHOOTING
Data on Radio Shack's line of Archer brand
by Edward Bannon
semiconductors is compiled in this new refer-
Earn Your Reflecting the rapid advances of electronic
ence handbook that contains cross- reference
technology, this book presents the current
DEGREE status of color TV servicing. It is intended as
data on more than 36,000 semiconductor de-
by correspondence, while continuing your vices. The handbook also has sections on the
a teaching tool for instructors, technicians,
present job. No commuting to class. Study care and handling of transistors, soldering
and technical -school or trade -school stu-
at your own pace. Learn from complete and precautions, case styles and dimensions,
explicit lesson materials, with additional dents. A fundamental knowledge of radio and
testing of transistors, and a glossary of terms,
assistance from our home -study instructors. TV theory is assumed. Troubleshooting is
symbols, and abbreviations used in electron-
Advance as fast as you wish, but take all the discussed as it relates to color reproduction
ics. The hand000k is available from Radio
time you need to master each topic. Profit problems in the black- and -white sections;
Shack stores.
from, and enjoy, the advantages of directed bandpass amplifier; color -sync procedures; Published by Radio Shack, Forth Worth, TX
but self-paced home studÿ. chroma demodulators; chroma and color ma- 76102. Soft corer, 128 pages. $1.95.
The Grantham electronics degree pro- trices; systematic color circuits; color picture
gram begins with basics, leads first to the tube circuitry; modular procedures; and digi-
A.S.E.T. degree, and then to the B.S.E.E. tal color TV circuitry.
degree. Our free bulletin gives complete Published by Reston Publishing Co., P.O.
HOW TO DESIGN & USE MULTIVIBRATORS
details of the program itself, the degrees Box 547, Reston, VA 22090. 264 pages. by Courtney Hall
awarded, the requirements for each degree, $14.95 hard cover. Various types of multivibrators are examined
and how to enroll. Write for Bulletin E -77.
in this book at :he introductory level. Astable,
Grantham College of Engineering bistable, and monostable multivibrators as
2000 Stoner Avenue well as Schmitt trigger and half -shot circuits
P. O. Box 25992 are discussed. Other chapters explain the de-
DIGITAL /LOGIC ELECTRONICS HANDBOOK
Los Angeles, CA 90025 sign and applications of multivibrator circuits.
by William L. Hunter
The book also presents techniques for tailor-
Worldwide Career Training thru Home Study This handbook starts out with chapters on
CIRCLE NO. 20 ON FREE INFORMATION CARD ing circuits to meet specific demands. A few
numbering systems (binary, octa :, hex), basic
of the projects covered are pulse generators,
arithmetic operations, and the laws of logic
electronic counters, lamp flashers, tachome-
(Boolean algebra, Venn diagrams, truth ta-
ters, phase rreters, voice -operated relays,
bles) aspplied to digital circuits. The logic
and time -delay circuits.
chapter also gets into DeMorgan's Theorem
Published by Howard W. Sams & Co., 4300
for simplityingBoolean equations. The next
W. 62nd Street, Indianapolis, IN 46206. 96
two chapters explore logic circuits such as
pages. $3.95 soft cover.
flip -flops, counters, adders, converters and
multiplexers, and basic digital circuits includ-
ing multivibrators, gates, and the Schmitt trig-
ger. Logic symbols are examined thoroughly, RECORDING AND LISTENING GUIDES
as is the 54/74 family of TTL IC's. The last Master Hi -Fi Installation (151 pages), by Gor-
358 Ways To Save On chapter, on logic applications, looks at a digi- don J. King, describes in a straightforward
tal- readout timer by Sprague, and four digital manner the functions of the main compo-
Instruments, CB, Heath Kits (multimeter, clock, calculator, nents of a hi -fi system. It details the differ-
thermometer). ences between mono, stereo, and quadra-
Burglar Alarms, Publishea by Tab Books, Blue Ridge Summit, phonic sound and the effects of room acous-
PA 17214. 308 pages. $6.95 soft cover, tics. The guide is designed to help the reader
Automotive & Hobby $9.95 hard cover. select the right components for his audio sys-
tem. Master Srereo Cassette Recording (112
Electronics! pages), by I.R. Sinclair, covers just about ev-
The more you know about electronics, the erything you need to know to record and re-
more you'll appreciate EICO. Every EICO A DICTIONARY OF MICROCOMPUTING
play, and to maintain and improve your re-
product is designed to provide you with the by Philip E. Burton
cording equipment for professional results.
most pleasure and quality performance for If you are just getting into microcomputing or Coverage also includes noise -reduction
your money. The fact that more than 3 are just thinking about it, this is one book you equipment and special techniques and equip-
million EICO products are in use attests to might want to get at the start. It translates and ment for considerably boosting the quality of
heir quality and performance. defines the meanings of such things as ACIA, recordings. Master Electronics In Music (120
DMA, DOS, assembler, emulator, handshak- pages), by T.D. Towers, is a guide to the pro-
"13UILD -IT-YOURSELF" and save up to
ing, iteration time, and a host of other terms per use and maintenance of such popular
50% with our famous electronic kits. and phrases used in computing. For exam- electronic instruments as electric guitars,
For the latest EICO Catalog and name of nearest ple, it will make clear the difference between electronic organs, amplifying systems for mu-
EICO Distributor, check reader service card or software, firmware, and hardware; JUMP and sical instruments, and other electronic musi-
send 500 for fast first class mail service. LOOP instructions; bit and byte; etc. Dia- cal equipment
EICO -283 Malta Street, Brooklyn, N.Y. 11207 grams, drawings, and tables are provided to Distributed by Hayden Book Co., Inc., 50 Es-
illustrate the text. The Appendix contains the sex St., Rochelle Park, NJ 07662. Soft cover.
Leadership in creative
electronics since 1945. E/CO complete listing of the full ASCII code; tables $5.45 per volume.

CIRCLE NO. 13 ON FREE INFORMATION CARD POPULAR ELECTRONICS

 ELECTRONICS MARKET PLACE
REGULAR CLASSIFIED: COMMERCIAL RATE: For firms or individuals offering commercial products or services, $2.25 per word. Minimum order $33.75,
EXPAND -AD CLASSIFIED RATE: $3.35 per word. Minimum order $50.25. Frequency discount; 5% for 6 months; 10% for 12 months paid in advance. READER
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cover date (for example. March issue closes January 1st. Send order and remittance to POPULAR ELECTRONICS, One Park Avenue, New York, New York
10016. Attention: Hal Cymes.

FOR SALE POLICE /Fire scanners, large stock scanner crys- SOUND SYNTHESIZER KITS -Surf $12.95, Wind $12.95,
Wind Chimes $17.95, Electronic Songbird $6.95, Musical
tals, antennas. Also CBs. Harvey Park Radio, Accessories, many more. Catalog free. PAIA Electronics,
FREE! Bargain Catalog-
-C.'s, LED's, readouts, fiber
I
Box 19224, Denver, CO 80219. Box J14359, Oklahoma City, OK 73114.
optics, calculators parts & kits, semiconductors, parts. TELETYPE EQUIPMENT for sale for beginners and exper- BUGGED ? ?? New locator finds them fast. Write, Clifton,
Poly Paks, Box 942PE, Lynnfield, Mass. 01940. ienced computer enthusiast. Teletype machines, parts 11500-L N.W. 7th Avenue, Miami, Florida 33168.
GOVERNMENT and industrial surplus receivers, supplies. Catalogue $1.00 to: ATLANTIC SALES, 3730 YOU WILL SAVE BIG MONEY! Surplus, Ctearouts,
transmitters, snooperscopes, electronic parts, Picture Nautilus Ave., Brooklyn, NY 11224. Tel: (212) 372-0349. Bankruptcy, Inventory, Deals. Catalog $1 (redeemable).
Catalog 25 cents. Meshna, Nahant, Mass. 01908. ELECTRONIC ignition: Capacitor-Discharge, pointless. ETCOA Electronics, Box 741, Montreal, H3C 2V2. U.S.
LOWEST Prices Electronic Parts. Confidential Catalog Auburn Sparkplugs. Wheel Stabilizers. Information 20 Inquiries.
Free. KNAPP, 3174 8th Ave. S.W., Largo, Fla. 33540. cents. Anderson Engineering, Epsom, N.H. 03234. HEAR POLICE /FIRE Dispatchers! Catalog shows
ELECTRONIC PARTS, semiconductors, kits. FREE FLYER. WHOLESALE C,B., Scanners, Antennas, Catalog 25 cents. exclusive directories of "confidential" channels, scanners.
Large catalog $1.00 deposit. BIGELOW ELECTRONICS, Crystals: Special cut, $4.95, Monitor $3.95. Send make, Send postage stamp. Communications, Box 56 -PE,
Bluffton, Ohio 45817. model, frequency. G. Enterprises, Box 461P, Clearfield, UT Commack, N.Y. 11725.
84015. UNSCRAMBLERS: Fits any scanner or monitor, easily ad-
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Cornell, 4213 University, San Diego, Calif. 92105. justs to all scrambled frequencies. Only 4" square $29.95,
COMPUTER HOBBYISTS -classified advertising fully guaranteed. Dealer inquiries welcomed. PDO
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Science Fair Students...Construction plans- Complete,
24695 Santa Cruz Hwy., Los Gatos, CA 95030. RECONDITIONED Test Equipment. $0.50 for catalog.

--
including drawings, schematics, parts list With prices and
sources...Robot Man Psychedelic shows
- -
Lasers - Walter's Test Equipment, 2697 Nickel, San Pablo, CA
94806.
Adapter -
Emotion /Lie Detector Touch Tone Dial
Transistorized Ignition -
Quadraphonic
Burglar Alarm
Sound Meter...over 60 items. Send 50 cents coin (no
- ORGAN KITS CB RADIOS, monitors, crystals, CD ignitions. Southland,

stamps) for complete catalog. Technical Writers Group, KEYBOARDS Box 3591 -B, Baytown, Texas 77520.
SURPRISES GALORE! Projects, ham radio, music synthe-
Box 5994, University Station, Raleigh, N.C. 27607. THE ULTIMATE IN DESIGN
sizers, etc. IC's, pots, hardware, crystals, keyboards, re-
METERS -Surplus, new, used, panel or portable. Send for
AND SOUND
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list. Hanchett, Box 5577, Riverside, CA 92507. Demo Record & Brochure $1.00 26231B, Salt Lake City, Utah 84125.
Wunitzsr reproductions

Greatest Values -
MECHANICAL, ELECTRONIC devices catalog 10 cents.
Lowest Prices. Fertik's, 5249 "D ",
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gti DEVTRONIX ORGAN PRODUCTS, Dept. C
5872 Amapola Dr. San Jose, CA 95129
NAME BRAND Digital /Analog Test Equipment. Discount
prices. Free catalog. Salen Electronics, Box 82, Skokie, Il-
linois 60076.

MINI-KITS
SIX DIGIT 12/24 HR.
VIDEO TERMINAL FM WIRELESS
MIKE KIT
CLOCK KIT KIT $149.95 FM1 $2.95

$22.95
A compact 5 x 10-inch PC card that requires only an ASCII
MODEL DC -5 keyboard and a TV set to become a complete Interactive terminal to'
connection to your microprocessor asynchronous interface Its TONE DECODER KIT
many features are. single 5-volt supply, crystal controlled sync and
baud rates (up to 9600 baud). 2 pages of 32 characters by 16 lines
read to and from memory. computer and keyboard- operated cursor
The best looking, most complete kit on the market'. Features Include time set and page control. parity error display and control. power-on
pushbuttons. Jumbo 4" readouts. Polaroid lens filter. line cord transformer, initialization. lull 64- character ASCII display. block -type see -thru
super quakty PC boards and durable extruded aluminum case available in five cursor. Keyboard computer control backspaces toward spaces Complete nit, TOT $4.95
ditlerent colors All parts are included. there are no extras needed, Super instructions line feeds. rev line feeds home. returns cursor Also clears page
reduce assembly time to -2 hours. Fully guaranteed. Colors available- gold, silver, bronze,
1
cleats to end of line selects page 1ór 2, reads from or to memorl
blue and black (specify)
Clock Kit. DC-5
Alarm Clock Version. DC-8
12/24 Hr. Clock with 10- Minute ID Timer, DC -10
$22.95
524.95
The card requires 5 volts at approx. 900 ma and outputs standard 75
ohm composite video
TH3216 Kit $149 95
LED
SLINKY KIT tip.
$25.95
TH3216. Assembled and Tested $239 95
Vo -t, Video to RF Modulator Kit $ 695 oanel
Complete$ Kit, B1.1:! $2.95

CAR CLOCK KIT CALENDAR ALARM CLOCK KIT CAR

SUPER -SNOOP AMPLIFIER

6 -Digit 12/24 HR. 6 -Digit 12/24 Hour CLOCK

High Accuracy (1 Min. /Month) Has every feature one could ever ask for Kit includes all parts except
KIT $27.95 Complete Kite BN.9 $4.95
Big 4" high readout case. build it into wall, station or even cari Uses the incredible 7001
Special circuit suppresses chip Features
t2. 24 -Hour 12-Volt AC or DC
all spikes and transients
High Accuracy (1 minute. month) MUSIC LIGHTS KIT
6-digit 5" high
6 Jumbo 4' LED readouts
Same case as DC -5 above Calendar Shows mo day Easy. no- polarity hookup
Displays blanks with ignition 24 -Hour alarm with snooze
Display blanks with ignition
Complete Kit, DC -7 525.95 12- or 24 -Hr. Format
Case. mounting bracket included
Battery backup with
Super instructions Complete Kit,ML.1
on-Chlp time base $7.95
Complete Kit. DC-11 $27 95
Complete Kit less 990 Dl, 3 $34 95
SIREN KIT
741 OP-AMP MA -1003A CAR CLOCK MODULE $23.95
MA -1002A ALARM CLOCK MODULE $12.95
600 mHz 1.0 10 for 52.00
Includes transformer and switches
Auto dimmer photocell for 5 ,I .vitra 1002
Complete Kit, 5M -3 52.95

Prescaler CODE OSCILLATOR KIT

$59.95 LINEAR REGULATOR TRANSISTORS Ii.
batten
trcticator and code
vo ire.
555 .50 309K .99 NPN 2N3904 type 10 /$1.00 Complete Kit, CP0. 1 $2.50
Fully assembled and tested. 556 75 309H .99 PNP2N3906 type 10 /51.00
Extend the range of your counter to 10 times higher in frequency. 567 1.75 340K -12 .99 NPN Power Tab 40W 3/51.00
Works with any counter High sensitivity input with built -in 1458 .65 7805 .99 PNPPower Tab 40W 3/51.00 POWER SUPPLY KIT
on-chip pre-amp 7812 MPF.102 type as
P5-1B. 10 559.95
LED DRIVER .99 FET 3/52.00 mg;
75491 .50 7815 .99 UJT 2N2646 type 3/52.00
75492 .50 7818 .99 2N3055 NPN -Power .75 -itivicer°
Cmplata Kit, PS-31.7 56.95

rarnsaU gIactrorilics Telephone

Orders
Welcome BASK
master dle23
Satisfaction guaranteed or money
refunded C,O.D orders add $1.00
DECADE COUNTER PARTS KIT

Orders under $10.00 add $.75

N.V. residents add 7% sales tax rum
P.O. BOX 4072 ROCHESTER, N.Y. 14610 (716) 271 -6487 Kit of Parts, DCU -1 $3.50

CIRCLE NO 42 ON FREE INFORMATION CARD

JULY 1977 97
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DIGITAL
SPECIAL SUMMER SALE (GOOD THRU AUGUST) tion to Electronic News Letter, $1.00. Don Britton Enter-
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7453 .14 2532 2.29 or 14 pin .69 (RED EMIT.) linois 60076.
74181 1.95 340T 6V 1.09 RU -03.160' .14 SURPLUS COMPONENTS, Communication and test equip-
74123 .49 CALCULATOR 723 DIP .49 DL 702 RED C.C. ment. Illustrated catalog 25 cents. E. French, P.O. Box 249,
74153 CHIP mDIP .25 .30" LHD .99

A's.
.69 741 Aurora, Illinois 80505.
74154 .99 5738 1.95 1458 mDIP .53
74C00 .13 75453 mDIP .27 KEYBOARD
a o o.i ANYONE AN SOLDER WITH-
UNIVERSAL BREADBOARD 20 KEYS
2 SLIDE SO mug DO- IT- YOURSELFERS!
3' x 3'." 0000
(7 S .69 Let Kesler solder aid you in your home repairs
2 triple rows o( 27 holes for DIP IC's.
Addition space for transistors, resisto rs
1
A`.
0©ß[9
plumbing, etc. Save money -
or hobbies. A radio, TV, model train, jewelry,
repair it yourself.
Send self -addressed stamped envelope to Kester
& capaci ors. Very versatile & simple to $i.29 for a FREE Copy of "Soldering Simplified ".
use,1 /16' phenolic with silver plated
canner rlrroitr 11114" x 5 1/16" 1024X1 STATIC RAM 16 PIN KESTER SOLDER /
4201 Wrightwood Ave.
Chicago, Ill. 60639
^`
:444 .D last .v 7ns3 .9
LED s SHIFT REGISTERS
EACH TELEPHONES UNLIMITED, Equipment, Supplies,
Tat .16 7451 .17 74154 1.20
7442 .15 7454 .D 74,55 .97 DL1 OA RED CA .27" LHD $1.89 2502 1024 bit MULE DYN 16 pin $3.75
7403 .15 7460 .17 74156 .97 DL 707 RED CA .30" RHD 1.49 2504 1024 bit MOLT DYN 8 pin 3.75 All types, Regular, Keyed, Modular. Catalog 50
7444 16 7444 35 74tH .9 DL 507 RED CA .50" RHO 1.49 2511 Tri -State Dual 50- 104200 bit
'445 ]Sus .35 lase 1.71 FND 359 RED cents. Box 1147E, San Diego, California 92112.
'60 .19
.20 7470 -30 74160 1.23
CC .375" RHD 89 STATIC 14 pin 2.95
.667 .28 7472 OR 74Q, .97 DL 702 RED .30" MO
CC 1.39 2518 Hex 32-bit STATIC 16 pin 2.95 FREE CATALOG. Solar Cells, Nicads, Kits, Calculators,
r40 ,10 7471 .35 74162 139 NSN 74R RED .30" RHD
CC 1.49 2519 Her 40-bit STATIC 16 pin 2.95 Digital Watch Modules, Ultrasonics, Strobes, LEDS, Trans-
409 .M 704 .20 74163 109 DL 500 MO .50" RHO
CC 1.49 2527 Dual 256 bit STATIC 8 pin 2.95
istors, IC's, Unique Components. Chaney's, Box 27038,
roe .16 7475 .A 141M .9! MANS GREEN CA .27" LHD 1.39 2532 Quad 80 bit STATIC 16 pin 3.95
706 .30 74165 .9 1.39 5013 1024 bit accum. Dynamic 8 pin 1.75 Denver, Colorado 80227.
7411 .25 MANS YELLOW CA .27" DID
»u .43 real .60 74166 1.25
MAN82 YELLOW CA .3" LHD 1.89 5016 500/512 bit Dynamic 8 pin 1.59 POWERFUL, ADJUSTABLE, REGULATED, THREE OUT-
)414 .65 ]445 .0 74170 2.10
]ató 3s 746 .40 74173 1.q MAN66 RED CA .6" LHD 2.19 -

PUT POWER SUPPLY and 900 easily removable parts in

2.39
7427
7420
rizo
35
.16
7490
7490
7492
x43
.43
.75
74174
74175
74176
1.23
.97
.9
131-747 RED CA .6" LHD

,
J
745200 complete CARTRIVISION television recorder electronic
assembly with documentation. Perfect for

.LJ
.3F
Tan .29 702 .4i 7417i .04 SPECIAL DEVICES 256 BIT RAM TRI -STATE MICROPROCESSOR, IC, transistor, television, CB radio
.0 371 AF -IF ShopDetector DIP 2.93
7425 .27 7493 74180 .90
50 AM Radio Rmeiver Subsystem DIP
applications. $21.45. Free brochure. MADISON ELEC-
7426 .6 7494 . » 74181 2.45 .75
TRONICS, INCORPORATED, 369, D55, Madison, Alabama
7427 7495 .79 74182 .79 1310 FM Stereo Demodulator DIP 2.90
.29
aala.red Madutato..Donodulator rW 35758. SATISFACTION GUARANTEED.
7430 .20 7496 .» 74214 Lee 106
1800 Stereo multiplexer DIP
.94
20 1O/a OFFWITH$25ORDER
7432 74100 As ]4186 710
.23
34dbtbpl ,nDtP CB RADIOS-Police Scanners, Wholesale only!! Send let-
7437 as 7410s
74107
44
.37
741e7
74590
5.75
1.15
ULN22138 FM Gain Mock
ULN229 FM Win Mock 44db (hp) ,nDIP
1.63
1.35
15% OFF WITH $100 ORDER
-
terhead for lowest prices anywhere. Four Wheeler, 10PE,
743e .25
1.25 2513 ammeter Generator M04x5 DIP -14 10.30 THESEDISCOUNTS APPLI 10 TOTAL
74121 .38 74191 New Scotland, Albany, N.Y. 12208.
7444 .15
-
/l,' olim
7441 .9 74122 .38 74592 .95 3046 Traoodua Array DIP -14 .73 OF ORDER SPECIALS INCLUDED
LEDS, red with mounting clip 20 cents each, 10 for $1.80
7442 .59 74123 .65 74191 85
7441 .73 74125 .54 74194 1.25
7444 .73 74126 .58 74295 .74 RESISTOR KIT ' prime parts. 75 cents postage and handling. CA res. add
7445 .73 74732 .9 74916 1.25
MAIM' Rf((4B7(/IY 1A WATT 01255 6% tax. Hooker Electronics, P.O. Box 386, Hanford, CA
7146 .81 7414í 1.44 ]4197 73 1/2 WATT 01505
7447
144S
7450
.»
.»
.17
74145
74150
74252
1.44
.97
.»
74198
74199
74200
173
1.69
5.15
Carbon 1,Im r 5%
1/4 or 1/2 watt
455 resistors. 44 values
1!3a
. 19.95 $$$
93230.

No. bita
PROMS PROGRAMMED
256 1024 2048 4096
ICSOCKET[ Supplied in a 15 drawer. ADOL SHIPPING CHGS TTL S 7 up S 8 up S 11 up S 19 up
Solder T011 - low profile
8
lapin
16
pin

pin
S .17
,p
.22
24 pin
M pin
0 pin
.42
.59
.69
60 compartment storage
cabinet -
table or wall
mount. Ready to use.
RESISTOR ASSORTMENT
R (OAMSI
52.00
. .
Schottky
MOS -
10 up
-
11 up 19 up
45 uD
33 uD
Price depends on mfr. type. Send $1.00 packet fee now, bits
25 up

18 pin _29
QTY. QTY. QTY.
desired. Receive specs on all our PROMS, program sheets,
R QTY. R QTY. R R R
WIRE WRAP RM pMb PROM postage credit. Pencil in program sheets, remit balance
14 pin .49 1.5 5 68 5 2.2K 20 33K 20 330K 10 of price. We will send new guaranteed programmed PROM.
10 2.7K 10 470K 70
LINEAR CIRCUITS 3.3 5 220
10
3911
47K
10
10 680K 10
Send packet fee (check or money order only) to:
f 6.8 5 270 5 3.310
700 .71 311 242 723 .62
10 10 3311 10 3.9K 10 68K 10 2.2M 5 RBH Enterprises, Box 12344, Wichita, KS 67277
set .29 176 .M 733 NE
3.3M
51 15 5 470 20 47K 20 100K 20 5
302 300 130 739 1-0 6.4K 10 15010 10 4.74.4 5
3z 22 5 680 10 RADAR DETECTOR KIT. Build a long range radar detector
se' .80 380-8 t 25 742 10 220K 10
.n .1i 33 5 1.0K 20 22K
305 381 175 747
47 10 1.5K 10 27K 10 270k 5 with over one mile range. Kit comes with complete docu-
307 .26 382 175 7M ,35
i08 3H sit 195 1458 .62
mentation and drilled, etched and plated PC board. Only
39k 135 sae 195 ilso 2.4a FREE CATALOG AVAILABLE ON REQUEST $4.95. Thousands sold nationally. Satisfaction guaranteed.
310 1A7
550 .» 3900 .49
Same day shipment. J.B. Saunders Company, 3050
2 .95
555 6 7114 .71 Satisfaction guaranteed. Shipment will be made postage prepaid within 3 days Iran
Valmont, Boulder, Colorado 80301.
11119 137 556A 1.19 7525 .90 receipt of order. Payment may be made with personal check. charge card (include
1201 1.39 8038 4'25
I". 139
544
562
309
gm 8864 2.15
number and yip. date). or money order. Phone Orders -8.314 and M/C card or C.O.D SEEKING JAPANESE TRANSISTORS for CB Repair? Re-
70 170 565 1.18 75150 1.75 quest list. Fuji -Svea Enterprise, Dept. P, Box 40325, Cinci-
324 152 75451 .35 Add 51.00 to r over shipping and handling if order is less than S10.00. netti, OH 45240.
-
566 1.95
339 Ise 567 1.95 75452 .35 California residents add sales tax. Include shipping expense for orders shipped out of
140K 1.69 ]9 .26 75453 .35 U.S. and Canada approx. 10 ".. of order. PROFESSIONAL UNSCRAMBLERS several models that
3467
372
149
2.93
710
711
35
.26 iii :p INTERNATIONAL ELECTRONICS UNLIMITED fit any scanner. Free information. Capri Electronics, 8753T
Windom, St. Louis, MO 63114.
Dw
Add 5.30 ea.
IMP
K Kean Y
°'fir on roc
inked below Stm
p1
0
VILLAGE SQUARE, P.O. BOX 449'
CARMEL VALLEY, CA 93924 USA
PHONE (408) 659-3171
BREATHE Better Air With Negative Ion Generator $275.00.
(Kit $165.00.) Golden Enterprises, Box 1282PE, Glendale,
Arizona 85311.
CIRCLE NO. 24 ON FREE INFORMATIONI CARO
98 POPULAR ELECTRONICS
 - -
UNSCRAMBLE CODED MESSAGES from Police, Fire and PRINTED CIRCUITS. Pint photo resist with aerosol $15.25.
C2708, 8K EPROM: $35.00; C1702A: $7.50. PRO-
Medical Channels. Same day service. Satisfaction guaran- Quart developer $5.60. Four packs dry etchant $5.56. Pint
teed. Don Nobles Electronics, Inc., Rt. 7, Box 265B, Hot GRAMMING: $20.00; C1702A
C2708 tin plating solution $6.50. 8x10 auto lock exposure frame
Springs, Arkansas 71901. (501) 623-6027. $5.00. HEX OR OCTAL LISTING. ELECTRONIC $11.50. Ultraviolet lamp $16. Shipping prepaid. CIRCOLEX,
UNSCRAMBLERS)DESCRABLERS: If you have tried the Box 198, Marcy, N.Y. 13403.
DISCOUNT SALES, 138 N. 81st Street, Mesa,
"cheapie" Squawk -Box unscramblers and have had GAMES for HP -55: Lunar Lander, Racetrack, Blackjack,
nothing but squeals and frustration, then breathe new life Arizona 85207 Tank, Submariner, Nim; $6. McCabe Engineering, 8107
Into your scanner with our CODE -BREAKER. Tunes all DEAD BATTERY? Lights left on. Easily installed alarm Winsford Ave., L.A., CA 90045.
scramble frequencies and operates with all scanners and alerts driver with pulsing tone. $12.95 postpaid. CFL
monitors. Factory built and guaranteed. $34.95. Catalog of CUT & STRIPPED 30 AWG Wire $9.10 per 1000. Price list
Enterprises, P.O. Box 415, Export, PA 15632. free. Electro Products, 6110 S. Pilgrim St., Seattle, Wash-
many other descramblers and unusual electronic items, 25
cents. COD orders Tel. (501) 273 -5340. KRYSTAL KITS, MICROCOMPUTER HARDCOPY. Attachment converts any ington 98118.
Box 445, Bentonville, Ark. 72712. electric typewriter. Free Brochure. Stout Microcomputer, ELECTROLYTIC CAPACITORS top quality, reasonable
Box 1573, Fremont, CA 94538.
TELEPHONE technology. Recent Schematics, ads,
manuals. 5,000 pages: $9.95 Guaranteed. Automated, Box FREE CATALOG of Goodies -
Clock kits, power supplies,
price, prompt delivery and free brochure. Ecom Parts Div.,
3417 W. 8th St., L.A., CA 90005.
1027, Issaquah, WA 98027.
-
DVM kits, LED's, semis, all at lowest prices. DIAMOND-
BACK, Box 194P, Spring Valley, IL 61362.
WIRE -
Stranded and solid conductor
- - -
Wire Wrap -
--
ANYTHING ELECTRONIC we've got it. Catalog $1.00. Ribbon cable and connectors MORE. Send 13 cents
Razoo, Box 1224, Cupertino, Calif. stamp for complete list. Ram Electronics, Box 336-P,
SLEEP UNDISTURBED! Mask unwanted sound with
soothing "pink noise ". $57.50. Golden Enterprises, Box
1282 -PE, Glendale, Arizona 85311.
-
TANK
PLANS
TV GAME, Complete construction
$10.00; P.C. BOARD $55.00; KITS
$195.00; FREE information. ADVANCED
- Brookhaven, N.Y. 11719.
CARBON FILM RESISTORS 1 /4W, 1/2W - 1.7 cents each.
FREE sample / specifications. Other components. COM-
PENNY FORMULAS. Private collection. 1,000 easily pre- PONENTS CENTER, Box 134P, New York, N.Y. 10038.
pared product formulas only $10. Distributor, R7B68, ELECTRONICS, P.O. Box 133, Corvallis, OR FREQUENCY ALLOCATION CHART 2Khz- 2000hz. Send
Milton, Florida 32570. 97330. $2.00. Collins Chart Co., Box 1067, Coronado, CA 92118.

ITL 7400N TTL LOW POWER SCHOTTKY CMOS

SN7400N .13 SN74125N .40 SN74LSOON .23 SN74LS138N 1.25 CD4000BE .09 CD4035BE .99 CD4507BE .52
SN7401N .14 SN74126N .40 SN74LSO1N .23 SN74LS139N 1.35 CD4001BE .18 CD4040BE .99 CD4510BE
SN7402N .14 SN74128N 1.05
.59 SN74LSO2N .23 SN74LS145N 1.19 CD4002BE .13 CD4041BE .67 CD4511BE 1.25
SN7403N .14 SN74132N .69 SN74LSO3N .23 SN74LS151N .99 CD4006BE .99 CD4042BE .63 CD4512BE 1.15
SN7404N .17 SN74136N .59 SN74LSO4N .28 SN74LS153N .99 CD4007BE .17 CD4043BE .45 CD4514BE 2.50
SN7405N .17 SN74141N .88 SN74LSO5N .28 SN74LS155N 1.45 CD4008BE .80 CD4044BE .45 CD4515BE 2.50
SN7406N .25 SN74142N 3.70 SN74LSO8N .23 SN74LS156N 1.45 CD4009BE .37 CD4046BE 2.45 CD4516BE 1.10
SN7407N .25 SN74143N 3.98 SN74LSO9N .23 SN74LS157N .99 CD4010BE .37 CD4047BE 2.45 CD4518BE .90
SN7408N .17 SN74144N 3.98 SN74LS1ON .23 SN74LS158N 1.10 CD4011 BE .18 CD4049BE .37 CD4519BE .79
SN7409N .17 SN74145N .69 SN74LS11N .23 SN74LS160N 1.50 CD4012BE .17 CD4050BE .37 CD4520BE .79
SN7410N .14 SN74147N 1.58 SN74LS12N .25 SN74LS161N 1.50 CD4013BE .37 CD4051BE 1.15 CD4522BE 1.98
SN7411N .20 SN74148N 1.19 SN74LS13N .65 SN74LS162N 1.50 CD4014BE .89 CD4052BE 1.15 CD4526BE
SN74150N 1.50
SN7412N .21 .95 SN74LS14N 1.35 SN74LS163N 1.50 CD4015BE .89 CD4053BE 1.19 CD4527BE 1.50
SN7413N .39 SN74151N .61 SN74LS15N .23 SN74LS164N 1.60 CD4016BE .37 CD4055BE 1.29 CD45288E 1.20
SN7414N .64 SN74153N .61 SN74LS2ON .23 SN74LS168N 2.25 CD4017BE .94 CD4060BE 1.40 CD4531BE 1.25
SN7416N .24 SN74154N .95 SN74LS21N .23 SN74LS169N 2.25 CD4018BE .99 CD4066BE .59 CD4539BE 1.20
SN7417N .29 SN74155N .70 SN74LS22N .23 SN74LS170N 2.70 CD4019BE .42 CD4068BE .24 CD4555BE .75
SN7420N .14 SN74156N .64 SN74LS26N .37 SN74LS174N 1.25 CD4020BE 1.04 CD4069BE .24 CD4556BE .75
SN7421N .20 SN74157N .59 SN74LS27N .27 SN74LS175N 1.25 CD4021BE .99 CD4070BE .24 CD4585BE 1.80
SN7422N .20 SN74159N 2.50 SN74LS28N .30 SN74LS181N 3.30 CD4022BE .89 CD4071BE .24 74C85/40085PC
SN7423N .25 SN74160N 1.20
.85 SN74LS3ON .23 SN74LS190N 1.80 CD4023BE .18 CD4072BE .29 74C160/40160PC 1.50
SN7425N .25 SN74161N .85 SN74LS32N .33 SN74LS191N 1.80 CD4024BE .67 CD4073BE .29 74C161/40161PC 1.50
SN7426N .22 SN74162N .85 SN74LS33N .37 SN74LS192N 1.80 CD4025BE .17 CD4075BE .29 74C1 62 /401 62PC
SN7427N 1.50
.25 SN74163N .85 SN74LS37N .37 SN74LS193N 1.80 CD4026BE 1.39 CD40766E 1.05 74C1 63 /401 63PC
SN7428N .28 1.50
SN74164N .98 SN74LS38N .37 SN74LS194AN 1.30 CD4027BE .39 CD4078BE .24 74C174/40174PC
SN7430N .14 SN74165N 1.40
.97 SN74LS4ON .27 SN74LS195AN 1.30 CD4028BE .75 CD4081BE .24 74C175/40175PC
SN7432N .23 SN74166N 1.40
1.09 SN74LS42N .89 SN74LS196N 1.40 CD4029BE .79 CD4082BE .29 74C192/40192PC 1.50
SN7433N .30 SN74167N 2.75 SN74LS47N 1.10 SN74LS197N 1.40 CD4030BE .37 CD4085BE .75 74C193/40193PC
SN7437N SN74170N 1.50
.21 1.69 SN74LS48N 1.10 SN74LS221N 1.30 CD4033BE 1.60 CD4086BE .75 74C195/40195PC 1.40
SN7438N .21 SN74172N 8.75 SN74LS49N 1.10 SN74LS24ON 2.50 CD4034BE 2.95 CD4502BE 1.15
SN7440N .14 SN74173N 1.24 SN74LS51N .23 SN74LS241N 2.40
SN7442N .37 SN74174N .94 SN74LS54N .23 SN74LS242N 2.40 MOS AND BIPOLAR MEMORIES
SN7443N .68 SN74175N .84 SN74LS55N .23 SN74LS243N 2.40 P/N Description Price
SN7444N .85 SN74176N .77 SN74LS63N 1.75 SN74LS244N 2.50 C1702A Microsecond) 256 x 8 EPROM
SN7445N .65 SN74177N
(1 8.95
.76 SN74LS73N .45 SN74LS247N 1.30 Cl 702A (1.5 Microsecond) 256 x 8 EPROM
SN7446AN .70 SN74178N 1.19 5.95
S 74LS74N .45 SN74LS248N 1.30 C2708 1K x 8 EPROM (450 NS)
SN7447AN .67 SN74179N 1.49 SN74LS75N 49.00
.65 SN74LS249N 1.30 8080A 8 Bit MOS CPU (2 microseconds)
SN7448N .69 SN74180N .67 SN74LS76N .45 SN74LS251N 14.95
1.50 2102 -1P 1K Static Ram 1024 x 1 (450 NS)
SN7450N .14 SN74181N 1.94 SN74LS78N .45 SN74LS253N 1.50 2.50
SN7451N .14 SN74182N .59 SN74LS83AN 1.39 SN74LS257N 1.40
3342PC Quad 64 Bit Static Shift Register 4.50
SN7453N .14 SN74184N 1.75 SN74LS85N 1.60 SN74LS258N 1.40 3347PC Quad 80 Bit Static Shift Re
Register
9 4.50
SN7454N .14 SN74185AN 1.74 SN74LS86N .48 SN74LS261N 2.95 3341APC 4 x 64 MOS FIFO 1 MHz Shift Register 4.50
SN7460N .14 SN74186N 6.95 SN74LS9ON .89 SN74LS266N .55 TMS0117NC Decimal Arithmetic Processor 10.00
SN7470N .26 SN74188N 2.98 SN74LS91N 1.15 SN74LS279N .75 LCM1001 Microprocessor Learning Module 149.95
SN7472N .25 SN74190N 1.04 SN74LS92N .85 SN74LS283N 1.35 TMS4024NC 64 x 9 FIFO 8.95
SN7473N .29 SN74191N 1.04 SN74LS93BN .85 SN74LS29ON 1.30 TMS405ONL 4K Dynamic RAM Plastic 300NS (18 Pin)
SN7474N .29 SN74192N 6.95
.84 SN74LS95AN 1.50 SN74LS293N 1.30 TMS4060NL 4K Dynamic RAM Plastic 300N5 (22 Pin) 6.95
SN7475N .46 SN74193N .84 SN74LS96N 1.65 SN74LS295AN 1.75 AY5 -1013P 8 Bit UART
SN7476N .30 SN74194N .89 SN74LS107N 6.95
.45 SN74LS298AN 1.75 SEMI 4804A 4K STATIC RAM 1024 x 4 (450 NS) single 5V supply
SN7480N .35 SN74195N .54 SN74LS109N .50 SN74LS324AN 2.25 14.95
93415PC 1K RAM 40 NS Open Collector 11.00
SN7481AN .95 SN74196N .87 SN74LS112N .45 SN74LS352AN 1.45
SN7482N .55 SN74197N 93425PC 1K RAM 40 NS Tri -State 11.00
.73 SN74LS113N .45 SN74LS353AN 1.70
SN7483AN .65 SN74198N 1.64 SN74LS114N .45 SN74LS365AN .69 AM2901DC 4 Bit Bi -Polar Microprocessor
Micro D slice 31.50
SN7484AN 1.50 SN74199N 1.64 SN74LS122N .89 SN74LS366AN .69 AM2902PC Carry Look Ahead Circuit 3.18
SN7485N .84 SN74221N 1.14 SN74LS123N .99 SN74LS367AN .69 AM2905PC Quad 2 Input Bus Transceiver 8.10
SN7486N .30 SN74246N 1.95 SN74LS124N 1.95 SN74LS368AN .69 AM2907PC Quad Bus Transceiver with Tri -State Receiver and
SN7489N 1.85 SN74247N 1.70 SN74LS125N .75 SN74LS375AN .75 Parity 7.00
SN7490AN .43 SN74248N 1.75 SN74LS126N .75 SN74LS386AN .59 AM29O9PC 4 Bit Cascadable Microprogram Sequencer
SN7491AN .59 SN74249N 7.15
1.75 SN74LS132N 1.19 SN74LS395AN 1.95 AM2918PC Quad Deregister with Standard and Tri -State Outputs 4.32
SN7492AN .44 SN74251N 1.05 SN74LS136N .50 SN74LS670AN 2.75 F8 Kit 8 Bit Microprocessor Evaluation Kit with Software 185.00
SN7493AN .44 SN74265N .85
SS7494N .69 SN74278N 1.99
SN7495AN .67 SN74279N .57 TEXAS INSTRUMENTS DATA BOOKS FAIRCHILD DATA BOOKS
SN7496N .65 SN74283N 1.39 LCB1011 Understanding Solid State Electronics 2.95 Power Data Book 3.00
SN7497N 2.50 SN74284N 4.50 LCB1891 Software Design for Microprocessors 12.95 Bi -Polar Memory Data Book 2.50
SN74100N .97 SN74285N 4.50 LCC4041 Power Data Book
SN74104N .42 SN74290N .85
3.95 Linear Integrated Circuit Data Book 2.95
SN74105N .42 SN74293N .83
LCC4112 TTL Data Book 4.95 Low Power Schottky nd Macrolo 9 le TTL 1.75
SN74107N .28 SN74298N LCC4131 Transistor and Diode Data Book 4.95 Interface Data Book
1.92 LCC4151 Linear and Interface I.C. Data Book 3.95
SN74109N .47 SN74351N 1.92 1

SN74111N .52 SN74365N .65 LCC4200 Semiconductor Memories Data Book 2.95 Raytheon Linear Integrated Circuit Data Boot 1.50
SN74111N .69 SN74366N .65 LCC4230 O Ptoelectronics Data Book 2.95 Solid State Scientific CMOS Series Data Book 2.50
SN74116N 1.50 SN74367N .65 LCC4241 Linear Control Circuits Data Book 2.95 Unitrode Semiconductor Data Book 4.95
SN74120N 1.40 SN74368N .65
SN74121N
SN74122N
.34
.38
SN74390N
SN74393N
1.40
1.40
"ONLY MAJOR MANUFACTURERS SUPPLIED"
"This is a partial listing. Our complete catalogue lists many more device Distribution- I. QUALITY
SN74123N .48 SN74490N 1.90
"How can you beat the combination -
types & series which are available "Our quality cannot be surpassed ".
the finest quality; current produa
2.
3.
INVENTORY
PRICE

1977 IC UPDATE MASTER MANUAL

Brand new. Complete integrated circuit
struments & Fairchild Semiconductor -
At the lowest prices
an unbeatable combination. Get the most value for your Dollar".
Surely-
flan; latest date code devices from the major manufacturers as Texas In We now offer the lowest mix pricing for major manufacturers devices
only, with the largest variety of devices available from stock, from .ne
source.
Active Electronic provides the three essentials in Semiconductor We offer Rolls Royce quality at Volkswagen pricing.
data selector from all manufacturers. 1264
page ma rpr, guide so the latest !ers in -
eluding microprocessors and consumer cir-
cuits. 17,000 cross references for easier
sourcing of hard to get parts. P.O. BOX 1035 FRAMINGHAM, MASSACHUSETTS 01701
$29.95 with tree update service. Telephone Orders & Enquiries (617) 879-0077
NOW IN CANADA 5647 Ferrer st. 44 Fasken Dr -Unit 25 MINIMUM ORDER
$10.00 *
New Fall 1977 Catalogue Is Montreal, Quebec Modals, Ontario POSTAGE & HANDLING *
ADD $1.00 TO COVER
2 Locations Tel. (514) 735.8429 Tel. (416) 677-4287 Canadian customers add 30%
now Available on Request for duty and handling. All federal and provincial
taxes extra

CIRCLE NO. 99 ON FREE INFORMATION CARD

JULY 1977 99
 SELF -STUDY CB RADIO REPAIR COURSE. THERE'S
CLASSIFIED ADVERTISING ORDER FORM MONEY TO BE MADE REPAIRING CB RADIOS. This easy -
to -learn course car prepare you for a career in electronics
Please refer to heading on first page of this section
enabling you to earn as much as $16.00 an hour in your
for complete data concerning terms, frequency dis- spare time. For more information write: CB RADIO REPAIR
2 3 COURSE, Dept. PE07, 531 N. Ann Arbor, Oklahoma City,
counts, closieg dates, etc. WORD COUNT: 15
WORD MINIMUM. Include name and address. Okla. 73127.
4 5 6 Name of city (Des Moines) or of state (New York)
counts as one word each. Zip Code not counted.
LEARN WHILE ASLEEP! HYPNOTIZE! Astonishing details,
9 Count each abbreviation, initial, single figure or strange catalog free! Autosuggestion, Box 24 -ZD, Olympia,
7 8
Washington 98507.

--
group of figures or letters as a wad. Symbols such
as 35mm, COD, PO, AC, etc., count as one word.
10 11 12 GRANTHAM'S FCC LICENSE STUDY GUIDE 377 pages,
Hyphenated words count as two words. Telephone
numbers count as one word. 1465 questions witY answers/discussions covering third,
13 14 15 second, first radiotelephone examinations. $13.45 post-
Words paid. GSE, P.O. Box 25992, Los Angeles, California 90025.
16 17 18 INTENSIVE 5 week course for Broadcast Engineers. FCC
$2.25 (Commercial Rate)
$1.35 (Reader Rate) First Class license. Student rooms at the school. Radio
19 20 21 $3.35 (Expand -Ad Rate) Engineering Inc., 61 N. Pineapple Ave., Sarasota, FL 33577
and 2402 Tidewater Trail, Fredericksburg, VA 22401.
22 23 24
LEARN BASIC Digital Troubleshooting by corres-
Payment of S pondence. Course includes text and demonstration mod-
25 26 27
enclosed for insertions. ules. Educational Technologies, Box 224, Reynoldsburg,
Ohio 43068.
28 29 30 D AmEx D BAC © HIGHLY EFFECTIVE Degree Program in Electronics En-
33 D MC D Diners gineering. Advance rapidly! Our 31st Year. Free literature.
31 32
CHARGE: for insertions. Cook's Institute, Box 20345, Jackson, Miss. 39209.
You will be billed monthly.
34 35 36 BURGLAR/FIRE ALARM EXPERTS NEEDED for cars,
homes, industry. Learn high profit systems installation at
home spare time. Simple, quick, complete. Free informa-
Account # Expiration Date
tion by mail. No salesmen. Security Systems Management
Master Charge Interbank # (4 digits above name) School (homestucy), Dept. 7373-077, Little Falls, N.J.
SIGNATURE MUST BE PROVIDED BELOW 07424.
GET YOUR COMMERCIAL FCC License. New exams by
PRINT NAME author of successful published workbooks of FCC Practice
Tests. 500 Questions Second Class, $11.95; 200 First
ADDRESS
Class, $7.95; 100 Radar, $4.95; postpaid. Save, all three
CITY _ - - STATE ZIP $19.95. Complete mathematical solutions. Free counselling
service. Victor Veley, P.O. Box 14, La Verne, Calif. 91750.
SIGNATURE PE-777
t 1977 TESTS -ANSWERS for FCC First Class
SCORE high on F.C.C. Exams ...Over 300 questions and License. Plus "Self -Study Ability Test." Proven!
answers. Covers 3rd, 2nd, 1st and even Radar. Third and
INSTRUCTION Second Test, $14.50; First Class Test, $15.00. All tests, $9.95. Moneytack Guarantee. "FREE" BRO-
$26.50. R.E.I., Inc., Box 806, Sarasota, Fla. 33577. CHURE. Command, Box 26348 -P, San Francisco
UNIVERSITY DEGREES BY MAIL! Bachelors, 94126.
LEARN ELECTRONIC ORGAN SERVICING at home all
makes including transistor. Experimental trouble- kit- Masters, Ph.D's. Free revealing details. FCC License Preparation, Communications Electronics,
shooting. Accredited NHSC, Free Booklet. NILES BRYANT Electronic Technology with Lab., Television Servicing.
Counseling, Box 317 -PE7, Tustin, California Free Catalog. Gene Tech., 5540 Hollywood Blvd., L.A., CA
SCHOOL, 3631 Stockton, Dept. A, Sacramento, Calif.
95820. 92680. 90028.

ß E Ï ELECTRONICS

For USE on
zia){zi -3z4O P.O. BOX 19442P
DALLAS, TEXAS 75219

THE MK -05 MINI MOBILE is a compact 6 digit DC clock with a

faster ZIP all

quartz xtal timebase and alarm capability. The readout is a mag-
nified .125" LED calculator readout. Kit comes complete with
all components, PC board and instructions. 12 hour format
only. Do not be foaled by our low price, this is a quality time-
piece with voltage and noise suppression. 2$ X 24 X 11 $12.95

service CODE mail Own the most mange= electronic clock on the market! The MG-01
MINI GRANDFATHER has a swinging pendulum, matching
tick -cock sound, ana a pleasant bell -like chime that is adjustable
in pitch, volume and sustain. The chime sounds and counts the
hours (ie: 3 times 'or 3 o'clock). Kit comes complete with 2
plated and drilled IC boards (6.5 "x4.5 "). 7 CMOS integrated
circuits and a 40 pin clock IC. Also included are switches, speaker,
bright 4 digit .5' LED display with colon and all nec-
essary electronic components. $39.95 Kit (less case)
Beautiful solid wooe case over 8" tall custom cut for the MG -01
C CC
oDO
with ruby front filter and drilled rear panel. Available in WALNUT
8K EconoRAM II' w $ 163.84 or ASH (p /ease speciry). $18.95 finished, shipped unassembled
tinder ',a per bit!
Configured as two independent
OUR CUSTOMERS WRITE ABOUT OUR CDI KIT:

BILL GODBOUT ELECTRONICS

O O 4K
ing:
blocks for maximum flexibility. Full buffer-
tri - state outputs drive the S -100 bus or
any bidirectional bus: low power Schottky sup-
"..great kit."
"...unbe'ievable value ", "..good design!"
"(..fantastic kit and service. Send three more."
I RNs
BOX 2355. OAKLAND AIRPORT. CA 94614
Add 50e orders under SIS. Allow up to 5'-
r,r shipping; excess refunded. we require street
M port ICs plus selected RAMs give low power op-
eration; zips along at 450 ns or better (use
aft state with Z -BO). Low profile sockets in
1
The CDI kit is all these things and more. Get in on a one-time deal.
Complete electronics. $9.95
Requires heatsink (not included) also works for voltage source
eluded for all ICs. Plate througi, double -sided for high intensity strobe.
aldress
, LIS
for COD. BankAmericard' /Mastercharge'
min) call 415- 562- 0636,,'4h. CA res add tax. I) epoxy glass hoard.

NEW 4K EconoROM 265

UUv 10 Slot Motherboard S 85
MK -03 AIRCRAFT/CLOCK TIMER KIT.
You don't have to be a pilot to need the MK -03. If you want
a mobile clock that offers: six .4" LED readouts, 24 hour real

TT
S TIncludes 10 edge connectors; use as lMSAI add -on time readout, 24 elapsed time readout, alarm, snooze, display
or for stand alone system. Active, regulated blanking. Timer and clock share same set of readouts but are
with editor, assembler, and monitor terminations minimize crosstalk, overshoot, and
totally independent of each other. Timer has reset and freeze
feature. Many other options are available. Sold less case and
routines for the 8080
Improved listing. bigger and better - - -SP and P5W tl E E ocher bus problems. Epoxy glass hoard, quality
parts, s -tan compatible, heave power nyaces.
switches because of the various mountings and options available.
$26.95/complete electronics and boards less switches and case.
ire now

,diand
implemented

so
for greater user facility.
cry low power, quality board, sockets for all
Lind out what moved Jay Hell,
tor of Print -Out, to write
RRa 18 Slot Motherboard
Same features as above, but with 18 slots
S 118
edge
ULTRASONIC SENDER- RECEIVER KIT
A special buy on a -Ugh quality ultrasonic transducer allows us to
offer this kit at a super price -but hurry, quantities are limited!
"without a doubt, this board is the best buy connectors. You can build intrusion alarms, motion detectors, remote
have made for ay Altair 8800 out of the $50004 controls, echo ranting or liquid level measurement equipment.

KKK Terminator
1

I've spent." We supply the basic transmitter and receiver electronics includ-
PRINT -OUT, September 1976
Board S 29.50 ing a drilled and plated PC board. The units work at 23KHZ
with a range of 20 ft. and can be positioned opposite each other
Add active terminations to your bus, and clean
or side -by -side and bounced off a solid surface. The output will
,p the noise, crosstalk, ringing, and overshoot
sink up to 300ma to drive a relay, alarm circuit, etc.
CPU Power Supply
PP Y S 45 that can foul up data and crash programs.
Into
Plug
slot of ar S -110 compatible motherboard,
1
ORDER US-01 $19.95

ii th oltage protec-
crowbar .
and you are ready to go. AUTOMATIC TIME -OUT CIRCUIT for ultrasonic or mechanical
switch alarms. Provides a five second entry delay. Sounds alarm
,

tion, C% ',,A1,
_ -125 i ',A, and an adjustable S-
for one minute. then re-arms itself. Requires 6- 15VDC.
lo% bias supply. Although intended for small
computer systems, this is also a dandy little S DEALER INQUIRIES INVITED
CAVI
$3.95
bench supply for digital experiment.. TERMS: NO COD s Send check or M.O. '
Add 5% postage
Tx. Residents add 5% sales tax Foreign add 10% (20% airmail)
Orders under $10. add 60c handling Repair service available
CIRCLE NO. 19 ON FREE INFORMATION CARD Accepting phone orders on Master Charge and Bankamericard.

CIRCLE NO 8 ON FREE INFORMATION CARD

100 POPULAR ELECTRONICS

 DIGI -KEY CORPORATION
Quality Electronic Components NOey.tee4F
MDtlH BW-630
DON'T FORGET OUR NSN374 0.3 CA . 52.20/P
050584 0.5" 52.60/Pair
DISCOUNTS WHEN COMPARING PRICE .1,40144 050584 0.5"
CC
CA
.

. $2.60/Pair
NSN783 0.7" CC . 53.00/Pair

741500
PRICE BREAKTHROUGH ON 74LS'
.28 741530 .28 741590 .57 7415157 .75 7415248 79
-^,-`.. NSN784 0.7" CA . 53.00/Pair
741592 .57 7415158 .75 7415249 79 Battery ALL LEADS BROUGHT OUT FOR EASE OF APPLICATION

we
741501 .28 741532 .33
741502 .28 741537 .33 741593 .57 7415160 1.02 7415253 84
741503 .28 741538 .33 7415107 .39 7415161 1.02 7415257 75 She 0,85
741504
741505
741508
.29
.29
741540
711542
741547
.28
.67
7415109
7413112
7415113
.39
.39
7415162
7415163
7415164
1.02
1,02
1.02
7415258
7415266
746283
75
39
79
Wrapping 0.3 Digits
AdYOI

.29 .79 .39

741509 .29 741548 .77 746114 .39 7415168 1.14 7415290 65 tool
74610 .28 74651 .28 7415125 .49 7415169 1.14 746293 65
74611 .28 74654 .28 7415126 .49 74151701.73 7415365 67
74612
74613
741514
.28
.47
1.02
751555 .28
74673 .39
74674 .39
746132
7415136
746138 .73
.81
.39
74151731.34
746174 1.06
746175 .84
7415366
7415367
7415368 67
67
67 341 % Z
74615 .28 74675 .53 7415139 .73 746190 1.18 7415386 39 COMPLETE WITH BIT
741520 .28 741576 .39 7415151 .75 7415191 1.18 7415670 234 AND SLEEVE
741521 .28 741578 .39 7415153 .75 7415196 ,86 71695 77
741522 .28 741583 .79 7415154 1.10 7415197 .86 711.596 77
74626 .33 741586 .39 746155 .75 746247 .79 71697 77
741527 .33 7415156 .75 71698 77 WIRE WRAPPING WIRE IN BULK

INTEGRATED CIRCUITS - TTL, CMOS, LINEAR S. MOS 00. 52.00

Red er Rhek 30 ga.
500' 58.50
kpa.r
1000. 515.00
7400 .21 7476 .32 74181 2,15 4012
7401 .21 7480 .70 74182 .79 4013
23
40
4520
4527
1.14
1.68
SILICON DIODES
7402 .21 7482 .70 74184 2.19 4014 96 4528 .88 N4001 .64/10 5.50/C 549/M Sirte 1.25 "s1.2
7403 .21 7483 .70 74185 2.19 4015 96 4585 1.23 94002 .66/10 5.60/C $51/M
-1"
Dgits Actual
7404 ,21 7485 .89 74188 3.50 4016 40 2102-1 1.99 64003 .68/10 5.80/C 552/M
7405 .21 7486 .28 74189 3.50 4017 1 05 801306 24.95 N4004 .70/10 5.95/C
7406 .25 7489 2,19 74190 1,23 4018 05 C63046 .75 94005 .82/10 7.05/C f63ÌM
-
1
7407 .25 7490 .44 74191 1.23 4019 23 1M21119 1.25 94006 .90/10 7.75/C 369/M
7408
7409
7410
.21
.21
7491
7492 .44
.70 74192 .88
74193 .88
4020
4021
1

1
14
14
LM309K
LM3246
1.80
1.28
NM007
N4148
.99/10
.40/10
8.60/C
3.50/C 229%M
MA1003 CAR CLOCK NEW FOR CAR OR BOAT!
The MA1003 totale green flaurescent
.21 7493 .44 74194 .88 4022 96 LM3407-5 1.25 12 Heur Dufy display .Hen bri16ance that /canot
7411 .21 7494 .70 74195 .88 4023 23 LM340Tb 1.25 12 Volt DC be achieved by LED displays, a facture
7412 .21
7413 .25
7495
7496
.70
.70
74196
74197
.88
.88
4024
4025
84 1163401-0 1.25 Double Digit Discounts Crystal rite Base IMt said De/raitl
23 L6434011-12 1.25
7414 .89 74100 1,28 74198 1.49 4026168 LM1401-15 1.25 Save You Even More! Bright Green Digits
7416 .25 74107 .30 74199 1,49 4027 40 1.863407-18 1.25 Assembled and Tested
7417
7120
.25 74109 .33 74251 1.09 4028 89 1M340T-24 1.25 %s WATT ZENER DIODES
.21 74121 .35 74279 .55 4029 1 14 Uv13900N .88
7421 .25 747n .44 74365 .67 4030 23 16139099 .69 184522611 3.3v 15 $11/C 1052368 7.5v .15 511 /C
7423 .35 74123 .61 74366 .67 4033 1 51 MC1456V 1.00 1 N5227B 3.6v .15 S11 /C 185237013.2v .15 511 /C
7425 .35 74125 .40 74367 .67 4034 3 50 MC1458V .53 114522811 3.9v.15511/C 19523888.7v.15511/C
7426 .25 74126 .40 74368 .67 4035 14 1 MC3302P 1.15 1N52298 4.3v .15 511/C 18523989.1v.15511/C
7427 .33 74132 .70 8093 .40 4040 1 14 NE5367 3.24 1952308 4.7v.15511/C 195240810v.15S11/C
7428 .28 74141 .88 8094 .40 4041 79 NE5401 2.04 1852318 5.1v.15 E11/C 1852418 11v .15 511/C
7430 .21 74145 .70 9095 .67 4042 79 8185559 .48
1952324 5.6v .15 511/C 1 N5242B 12v .15 E11 /C
7432 .25 74147 1.63 8096 .67 4043 70 84E5566 .88
11152338 6.0v.15 S11/C 1852438 13v .15 511/C
7433 .30 74148 1.30 8097 .67 4044 70 NE560B 183 1 N52348 6.2v .15 511/C 18524413 14v .15 511 /C
7437 .25 74150 1.16 8098 .67 4046 86 1 NE561B 3.83
1 N5235V 6.8v .15 $11/C 195245815v .15 S11 iC
7438 .25 74151 .70 75150 1.16 4049 40 NE5628 183
7440 .21 74153 .65 75450 .88 4050 40 NE5656 1.25 BUT A -P PRODUCTS & BISHOP
7442 .53 74154 1.03 75451 .61 4051 126 9E566V 1.28 GRAPHICS FROM DIGI -KET
7443 .63 74155 .70 75452 .61 4052 1 26 NE567V 1.36
7445 ,70 74156 .70 75453 .61 4053 26 uA709CV 44
SIGNETICS ANALOG
1

7446 .70 74157 .70 75454 .61 4060 1 58 0.4171006 44

7447
7448
7450 .21
.70
.70
74160
74161
74162
.88
.88
.88
75491
75492
75493
.81
.84
1.09
4066
4071
4072
79
23
23
uA711CA
uA723CA
uA733CA
.53
.60
.75
MANUAL ... $5.95
7451 .21 74163 .88 75494 1.19 4073 23 u6741CV .44
7453 .21 74164 .96 82525 2.19 4075 23 uA747CA .70 PLESSEY SAMPLER
7454 .21 74165 1.15 4000 .23 4081 23 1.1A748CV .49 M Assomment of Menk,d Polyester Capacitors
7459 .21 74166 1.26 4001 .23 4082 23 u17805CU 1.25
7460 .21 74170 2,64 4002 .23 4502 79 uA7806CU 1.25 300 Caps 18 Values $26.00
7470
7472
7173
.30
.30
.30
74173
74174
74175
1.42
.98
.93
4006
4007
4009
1.23
.23
.79
4510
4511 05
4514 2 80
1

1
14 uA7808CU
416781201
uA7815CU
1.25
1.25
1.25 95L5053T-lYe
LED LAMPS
18 S1S/C
J 135 " "I3.0S "" MA1003 =24.95
7474
7475
.30 74176 .79
.79
4009
4010
.44
44
0515 2 80 1.25
r Actual Site !Midas 3 Push &mon Witches
.49 74177 4516 1 23 417824Q1
úA7B18CU 1.25 9515056 T-1 18 $15/C Digits
74180 .70 4011 .23 4518 1 14

RADIAL ELECTROLYTICS
Digits ABOUT OUR CLOCKS
.5" High The M11002 and

and
as
047010 serin dock modules by 0s6o..l 5wnkodw-
re fully assembled and tnNd clocks using a 4 apis LED dray
MOS integrated arasa on rS sane ben. Spry coaea
47/509...08
I/509 , , , .08
2.2/50V. . .08
.65/10
.65/10
.65/10
22/509...
100/6.39..09 .75/10
100/109.. 10 .77/10
12 1.00/10 330/25V.. 23
470/109.. 21 1.71/10
470/169.. 23 1.81/10
1.86/10

3.3/509...08 .65/10 100/169 ..11 .85/10 470/259..29 2.35/10

sornettes and cor spsckl nanfom.r and you tome a talla fuationmg 4.7/359...08 .65/10 100/250.. 13 1.10/10 1000/109 . 24 1.96/10
acre

y33-
4.7/509. .08 . .68/10 103/509.. 21 1.71/10 1000/169 . 29 2.35/10
the IM1003 dock module fully mseasW and aya I] bur
is a 10/169 _08
,08 .65/10 220/109. . 13 1.08/10 1000/2511 . 42 3.33/10
dock wing a Mph
high bilAmro seen (boat display ad use. 10/259 ...08 .65/10 220/169.,,15 1.16/10 2200/109 . 42 3.33/10
me recth k for 9d.r po, able uu Ir 10/509 . . .10 .75/10 220/259.. 21 1.71/10 3300/169.54 4.30/10
des tly dan t2 volts so p Our 22/169 ...OB .67/10 220/509..29 2.35/10 2200/258 . 58 4.67/10
nns
*Iodes tore. Faon canon wkdm f.. maire ris. time. 22/259 ...09 .70/10 330/109.. 15 1.16/10 3300/169 . 89 7.14/10
330/168.. 21 1.66/10
MÁ1002Á 3 LED 12 Mew NAPM Clod Module... SI0.50
MA1002A SET Module can uansfamer s Welches. $13.95
AXIAL ELECTROLYTICS
MA1002C 07/109 . . 11 .90/10 33/25V, , , 14 1.15/10 330/169..29 2.35/10
.s LM 24 Mer Clock Module $10.50 I/30V ... 11 .90/10 33/50V... 19 1.52/10 330/259.. 32 2.54/10
.4 MA1002C SET Modale with Tpmfomre4 %lanes $13.95 3.3/359 .. 12 .95/10 47/169... 14 1.15/10 470/169.. 32 2.55/10
3,3/509 .. 12 1.00/10 47/200... 470/250..37
,.r 17 1.30/10 3.00/10

o-o 1.3757E
MA1003 .z
MA 10104
van

air
ca Cadi wan
1.40 12 Mer M4á0
Switches

Cluck Module
$24.95
$13.00
4.7/259
4.7/359
4.7/509
10/2544,.. 12
..
.. 12
.. 12
I 1 .90/10
.95/10
1.00/10
1.00/10
47/509...
100/109..
100/169..
100/259.. 20
21
14
17
1.17/10
1.13/10
1.30/10
/ 10
1000 /109.33
1000/169 . 39
1000 /29
2200/109.50
. 56
2.65/10
3.15/10
4.50/10
3.96/10
MA 1O10Á SET Modulo with Tumfwmer 4 saches. $16.45 70/509... 14 1.15/10 100/509.. 29 2.30/10 2200/16V .62 4.95/10
Nctuol Sise: MA1010C O IEO N Mer Cbck Modula $13.00 22/165.
22/259.
22/509.
.

.
.

.
12
13
1.00/10
1.05/10
1.32/10
220/10V.
720/169.
220/25V.. 29
.

.
18
20
1.42/10
1,551.55/10
2200/259 . 79
3300/169 .95
4700/1691.09
6.36/10
7.63/10
MA1010C SET Mdule wirr Transforms 4 M6 7 , $16.45 . . 17 2.35/10 8.70/10
33/160... 12 1.00/10 220/500.. 40 3.23/10 10000/10V 1.15 9.19/10
MA1002A 12 Hour AM-PM 510.50 33010V..14 1.1610
MA1002C 24 Hour $10.50
SPECIAL TRANSFORMER L SWITCHES $3.45
Double Digit Discounts Save You Even More! WIRE- WRAPPING TOOL I.C. SOCKETS
Pin Solder .17
8 1.60/10
$5.95

O--
14 Pin Solder ,20 1.90/10
16 Pin Solder .22 2.10/10

High Digits
DATA BOOKS Wraps, Unwraps A 18 Pin Solder .29 2.75/10
F in IC's 595 p 54.00 Strips 30 ga. Wire 24 Pin Solder .38 3.60/10

0.84F , o Innaar Cs 957 p 55.00 28 Pin Solder .45 4.25/10

MA1010
CMOS 74C 256 p $3.00 40 Pin Solder .63 6.00/10
Memory Cs 592 p & 1/2 WATT 5%
1/2 8 Pin W-W .24 2.30/10
o Interface Cs 460 p
$3.00
54.00 CARBON FILM RESISTORS
14 Pin W -W .26 2.50/10

OO
16 Pin W -W .30 2.85/10
Volt. Regs. 128 p 53.00 18 Pin W -W .60 5.70/10
-
_-------- _
.
Lineor Appl. 1 432 p
Linear Appl. 2 246 p
S4.00
53.00
54 each h am9iphs of 5 per relue
81.70 /100 8 512.00 /1000 of ame salue
24 Pm W -W .96
28 Pin W -W 1.12
9.10/10
10.00/10
Audio 196 p 53.00 1 ohm thru 1.0 megohm 40 Pin W -W .92 8.75/10
4405/151 ICs 713 p 54.00
CMOS 4000 278 p 03.25
Analog Manuel 637 p 55.95 HARDWARE DOUBLE -DIGIT DISCOUNT SCHEDULE

SLIDE SWITCHES 2.56 1/4 Screw .99/C 7.20/M leers__ Wau., MasLepee Drew"
2 -56 1/2 Screw .99/C 7.65/M 3 0 0611499 ET $100.06499 W less 151
5751 15 1.20/10 10.00/C
440 1/4 Screw .55/C 3.60/M 5500.065999.99 loss 201
SPOT 19 1.70/10 13.00/C 440 1/2 Screw .60/C 4.05/M $15 W 5Ví.99 lots 10% 51000.00 4 Up los, 251
DPDT 23 2.00/10 19.00/C 6-32 1/4 Screw .65/C 4.40/M Thon Add the Ssso4N Mara. awlaw
6-32 1/2 Screw .75/C 4.85/M
STRANDED NOOK UP WIRE 8.32 3/8 Screw .90/C 5.85/M STANDARD SNIPPING /HANDLING CHARGE
20 go PVC.. 2.50/100' 10.00/500'
22 go PVC.. 2.80/100' 11.25/500'
8.32 5/8 Screw .99/C 7.00/M
2 -56 fies Nut 35/C 3.60/M If raw ...Anodisa totr r., diw..a h S1.ew
4.40 Nec Not .55/C 3.75/M s 0.066 4.99 .. add 12.00 S 50.06199.99. dd W.25
24 go PVC. 2.10/100' 8.50/500' 5.00.124.99 .. 8100.401 up
EE 6 -32 Nez Nut .60/C 4.007M s add $0.25 No Clnrpe
3
.

26 ga PVC.. 2.10/100' 8.50/500' 3-32 Hex Nut 105 00.149.99 ..dd 50.50
=.iI .60/C 4.15/M
No. 2 Lockwosher .85/C 5.757M sdK_ AlpPka noi l.we n IRA t [noel.
.7 5 lke 5 50 VOLT DISCS No. 4 Lockwasher .45/C 3.00/M

a= pct 100 pf
220 pf
470 pf
.001 uf
40/10
40/10
d0/10
40/10
3.50/C
3,50/C
3.50/C
3.50/C
No. 6 lockwosher .45/C 3.00 /M
No. 8 Lockwosler .45/C 3.00/M COD ORDERS ACCEPTED FOR SAME DAT
SHIPMENT -
CALL 218.6814674

h.. coMco
s.M for

MA1010A
MA1010C
12 Hour AM-PM

24 gour
$13.00
$13.00
SEND FOR OUR FREE CATALOG
WE STOCK A WIDE VARIETY OF
.0022 uf
.0047 uf
.01 uf
.022 uf
40/10
40/10
45/10
.50/10
3.50/C
3.50/C
3.65/C
4.00/C
"malme~"
w ke cord
"Only Quality Comporteras Sold.""
DON^. FORGET TO APPLY DISCOUNT SCNEDULI ose
SPECIAL TRANSFORMER d SWITCHES $3.45
PARTS NOT IN THIS AD PLUS
MANY SPECIALLY PRICED BARGAINSI
.047 uf
.1 uf
70/10
1 35/10
5.60/C
11.50/C DIGI -KEY CORPORATION
Box 677, Thief River Falls, MN 56701 218.681 -6674

CIRCLE NO. 11 ON FREE INFORMATION CARD

JULY 1977 101
HIGH FIDELITY BURGLAR ALARMS GOVERNMENT SURPLUS

DIAMOND NEEDLES and Stereo Cartridges at Discount DIALING UNIT automatically calls police. $29.95. Free MANUALS for Gov. Surplus radios, test sets, scopes. List
Frices for Shure, Pickering, Stanton, Empire, Grado and security equipment catalog. S &S Systems, 5619 -C St. 50 cents (coin). Books, 7218 Roanne Drive, Washington,
ADC. Send for free catalog. LYLE CARTRIDGES, Dept. P, John, Kansas City, MO 64123. (816) 483-4612. D.C. 20021.
Box 69, Kensington Station, Brooklyn, New York 11218. GOVERNMENT SURPLUS. Buy in your Area. How, where.
MUSIC GENERATOR -Real -time automatic composition Send $2.00. Surp us, 30177 -PE Headquarters Building,
MUSICAL INSTRUMENTS Washington, D.C. 20014.
and production of music. See Radio- Electronics, June,
1977 or write: Inner Space Electronics, Box 308, Berkeley,
JEEPS, TRUCKS, Typically from $52.40 ... Automobiles,
CA 94701. UP TO 60% DISCOUNT. Name brand instruments catalog. Boats, Motorcycles, Airplanes, Oscilloscopes, Tools,
Freeport Music, 114 G. Mahan St., W. Babylon, N.Y. 11704. Clothing, Sports, Camping, Photographic, Electronics
TUBES Equipment ... 200,000 Bid Bargains Nationwide Direct
from Government .. Low as 2 cents on Dollar! Surplus
SERVICES Catalog and Salen Directory $1.00 (refundable). National
RADIO & T.V. Tubes -38 cents each. Send for free Surplus Center, 2a0 Eastcass -PEL, Joliet, Illinois 60432.

I
Catalog. Cornell, 4213 University, San Diego, Calif. 92105.
TUBES receiving, factory boxed, low prices, free price list. SWL's, CB's, HAM' s. WDX will register your
WANTED
Trarsleteronic, Inc., 1365 39th Street, Brooklyn, N.Y. listening post and issue a certificate with call
112'8A, Telephone: 212-633 -2800. sign -type identification. Details for return post-
TUBES: "Oldies ", Latest. Supplies, components, sche- GOLD, Silver, Platinum, Mercury wanted. Highest prices
matics. Catalog Free (stamp appreciated). Steinmetz, 7519 - age from Monitor, P.O. Box 3333, Cherry Hill, paid by refinery. Ores assayed. Free circular. Mercury
PE Maplewood, Hammond, Ind. 46324. N.J. 08034. Terminal, Norwood, MA 02062.

A ..arts.,
128Y/ 1.50 21HB5 2.01
ELECTRONIC S 12CL3 1.52 21156 4.31
PARTS AND 12C1J5 1.85 211Z6 2.24

EDLIE
12906 2.21 211R8 2.09
ACCESSORIES ß
I 49 PH -331 REG.'
2.99 ' a 12DW4
12DW7
12FX5
12GN7
2.19
1.61
1.41
2.34
2.04
21LU8
22JF6
22JR6
22KM6
23Z9
2.04
2.79
2.99
3.23
2.15

'
12HL7

Stereophones
Comfortable. Light-
weight I
1AD2
1B3
70% OFF LIST!
1.67
1.67
6AR5
6AÚ4
.92
2.07
TUBE 121B6A 2.90
12MD8 2.00
12SL7 2.43
241E6
25CG3
291(06
3.36
1.46
3.53
25 -16k
With
Hz. Response
6-Ft. Cord & 3G"
Stereo Plug
' 1BC2
1K3
1S2A
1.59
1.67
1.04
6AU5
6AÚ6
6AU8
2.54
1.34
2.25 BONANZA
12SN7 1.85
12SQ7
12X4
3.72
.99
30AE3
31156
31LQ6
1.41
3.03
3.20
I 1114 1.67 6AV6 1.16
BLY BRAND NEW MANUFACTURER'S
13GF7 2.19 31126 3.54
2.74
NICKEL' 1V2
1X26
1.02
1.64
6AW8
6AX4
1.88
1.59
BOXED TUBES (Raytheon, Dumont, IEC
Mullard, etc.) AT 70% OFF LIST!
13Z10 2.69
148111 3.27
33GY7A
34CE3 1.68
CADMIUM 2AH2 1.67 6AY3 1.59 14BR11 2.60 35C5 1.37
"AA" Pen -Lite g 2AV2
2921
1.32
1.95
6AZ8
6BA6
3.37
1.41
MONEY BACK GUARANTEE 15BD11A 2.36
15CW5 1.43
35W4
35Z5GT
.93
1.49
Cells 1
2GK5 1.65 6BA11 2.06 Terms: Minimum order $10.00. Include postage. 15KY8 3.05 3606 3.53
Rechargeable 2HA5 1.43 6BC5 1.41 Either full payment with order or 30% depost, 16A8 1.71 38HE7 3.08
balance C.O.D. F.O.B. Levittown, N.Y. 16108 3.12 38HK7 3.00
Ea. For radios, calculators,' 3AT2 165 6BE6 1.55
BA-341 1.79 6BH6 1.59 11AY3 1.59 40KG6GA 3.42
etc. 1.2 Volt. 3BS2
42EC4A 1.77
178E3 1.59
Reg. Sale I 3CN3
3CU3
1.74
2.06
6BH11
6616
2.13
1.74
6F6GT
6FG6
4.09
1.43
61W8
6K6GT
1.41
1.71
7KY6
7V7
2.16
3.60 17BF11 2.51 42KN6 2.88
Mil. Cassette, Pkg. of 3, 819... 1.49 3CY3 1.85 6BK4 3.14 1.i3 17BR3 1.38 4585 2.70
118 TA- .81 6F07 2.40 6K7GT 2.40 8A8
3.30
2Y. REOI.E.D., Pkg. of 5, PL-233 .... 1.99 .59
3D13
3GK5
1.79
1.62
6BK7
6818
2.18
1.16
6FM7
6F67
1.94
1.28
6K8 3.60
2.04
8AC9
8AR11
2.413
3.12
17883
17CT3
1.59
1.43
50A1
5085 1.28
148 Min. 8 -Track Tape, TA -901 .69 .39 3HA5 1.61 68M8 1.56
6G E5 1.64 61(06 3.54 8BA11 2.36 17CU5 1.32 5005 1.29
I 3H05 2.39 6BN6 2.07 2.66 3.39 17DW4 1.58 50EH5 1.55
6GF7 2.24 6KE8 88M11
Elect. Cap. Kit, 50 Asst., CD-401 5.OB 1.10
3106 2.16 6BN8 1.73 171M6 2.55 50L6GT 2.06
6GH8 1.32 6KM6 3.54 88011 2.49
171N6 2.27 80 2.50
1 Black light Bulb. XM -291 100 .49 3V4 2.30 6BN11 3.09 6G17 1.25 6KT8 2.28 88011 2.42
2.10
CB Concerter for Car, CB-411 14.99 9.99 t 4AÚ6
4BZ6
4CB6
1.67
1.49
1.16
6BQ5
6B 7A
6B 8A
1.65
2.19
2.24
6GK5
6GK6
1.95
1.47
6KV6
6KZ8
2.81
1.71
8CB11
8C07
314
1.28
17106
17118
17KV6
2.25
1.74
3.05
6267
6973
7025A
2.03
1.32
Resistors V2-1 watt, Pkg. 100, RR-077 . 1.19 .19 6GM6 1.76 6L6G8 2.57 8CW5 1.113
7189A 1.82
I Yoklme Controls, 12 Asstd. VC-274 1.00 .49
1
4DT6
4EH7
1.64
1.52
6BV11
68X6
2.48
1.56
6GM8
6GS7
3.30
1.52
616
6L7
4.50
4.50
81U8
81V8
1,13
1.95
19CG3
1978
1.65
2.61 7199
7247
2.16
1.71
Empire 999 Mag. Phono Cart. PC -188 .. 9.99 6.99 4E17 1.52 6BZ6 1.32
6GÚ7 1.76 3.38 8LT8 1.68 20A03 1.31

I
'
1 -6Y DC Hobby Motors, 5 Asstd. M0 -333
Solder Terminal Strips, 40 Asstd. XM -501
2.00
1.30
59

50 1
4HS8
4106
41D6
1.58
2.15
1.98
6C4
6C5
6CA4
1.65
3.28
1.70
6GW8
6GX6
6GX7
1.47
1.46
1.92
6LE8
6LF6
6LF8
2.39
3.36
2.46
9A08
9GH8
9JW8
2.31
1.76
1.32
EjEicip
21GY5 2.10 7591
HIM
3.15

L1
4KE8 2.60 6C47 2.34 216
I 3.23 9KX6
i Ftil
®®
Double Face Foam Tape .3/4"152, TA -903 1.00 .80
6H6 3.33 8".
4L18 1.91 6CB6 1.40 6U8 1.85 10CW5 L43 [
6HÁ5 1.61
l: RPM Timing Motor, 111 VAC, MO- 211...49 5A05 1.61 6CD6 2.98 6LM8 2.04 10DX8 1.17
.30 6HB7 1.62
5AR4 2.15 6CG3 1.65 61.118 1.11 10GF7 2.18
Tape Mailers. 3" Pkg. 5, TA -936 .39
6HE5 2.01
.19 5CG8 1.71 6CG7 1.28 10GK6 1.91
6HF5 3.96 6LR6 3.23
I Ceramic Disc Cap., 100 Asstd. CC -210 . 1.29 .80 5EW6
5GH8
1.71
1.98
6CG8
6CJ3
1.82
1.58
6HF8 2.28 6178
6LU8
1.71
2.01
1OGN8
101T8
2.01
2.16 991456- DIGITAL COLOR CONVERGENCE
6HQ5 2.13
I(nob Kit, 25 Pcs. Asstd., KN- 030.... 1.00 .69 1 5G17 1.25 6CL3 1.70
6HS5 3.09 61X8 1.11 10JY8 1.56 GENERATOR BY SCIENCE WORK SHOP. The
miracle of Large Scale Integration (LSI)
I 3 -Track Tape Deck Chassis, RA -383 . 11.00 12.99
5GS7
5GX7
1.43
1.76
6CL6
6CL8
2.18
2.04
6HS6
6HS8
2.66
2.00
6M11
6MB8
3.30
1.95
10KR8
11AF9
2 15
239
which made the low cost pocket calculator
possible has now been applied to test equip.
Seg. I.E.D. Display Corn. K., XM -414. ment A single monolithic P- channel MRS

'I 1

Calculator Keys, 20 Asstd. XM -538

6Y. -5A. Transformer TF -041
...
2.00
.15

109
1.00
.39

.49
5HZ6
51K6
5116
5KE8
1.26
1.77
2.10
2.60
6CM6
6CM7
6CS6
6CU5
1.77
1.80
1.76
1.73
6HV5
6HZ6
615GT
3.72
1.34
1.77
6MD8
6MG8
6SA7
2.46
1.41
3,74
11AR11
11BM8
240
2.09
116711 3:17
11FY7 1.67
integrated circuit generates a composite
video signal, complete with all sync and
blanking pulses. Binary countdown from a
single master clock oscillator (rather than 2
617 6SG7 3.95
5118 6CW4 4.17 separate, unsynchronized oscillators) pro,
' 1.85 6Sl7GT 2.33 11KV8 2.31
258414 TO'66 Output Trans., TR -141 3.19 1.19 10 2.66 vides solid phaselock of all horizontal, ver,
5U4G8 1.31 6CW5 1.43 11L08 2.27
I 5Y3GT
5Y4GT
1.38
2.10
606
6DA6
2.39
2.10
6186
6106A
2.54
1.88
6SK7GT 2.40
6SL7GT 2.40
6SN7GT 1.59
11MS8 1.71
12AB5 L49
Bal and
COUNTER
matrix
color

switching
signals
ADJUSTMENTS!
there are NO
Using digital
techniques, 4 slide
I I 4.70 6018 2.50
6116 1.94 switches select any one of 16 patterns. A
6A8
61E6GA 3.51 6SQ7GT 2.42 12AT6 L19 unique oscillator /modulator stage provides
t 6AB4 1.61 6DK6 1.55 6T8A 2.01 12AT7 L43 both R.F. and VIDEO output for trouble-
61F6 2.90
6AC7 3.87 6914 2.39 1.52 shooting circuits by signal injection. Al-
@ I 64C10 1.82 6106 2.25
61H6
61Hß
1.50
2.64
6710
6U8A
2.36
1.64
12A116
12AU7 1.29
though primarily intended for servicing Col-
or TV sets, these compact (13/11' x 23/11' x
6AD1O 3.86 6976 1.40 6U10 1.70 12AV6 I.08 4 ") generators are excellent for amateur TV,
6JM6A 2.28

I 6AF4
6ÁF9
2.31
2.39
6DW4
69X8
1.58
1.17
61N6 2.13 6V6
6V6GT
4.01
1.92
12AX7
12AZ7
1.32
1.83
computer terminals, closed circuit TV, video
tape equipment, TV broadcast subsystems

electronics 6JS6C 3.12 and cable TV work. TV station type sent. No

6AG7 4.53 6E5 3.90 6X4 1.52 1284 1.86 counter adjustments. Crystal controlled
6116 2.54
6AH6 2.40 6EA8 1.65 1.55 12BA6 '.22 chroma osc. Epoxglass PC Bards. 2 year
6118 2.01 6X5GT
I 260 S. FORGE S27
T. P
GÁ18
6AL3
2.10
1.28
6E88
6EH7
2.52
1.61
61116 2.99 6X8 1.92 128E6 8.28
12BF11 249
warranty video & RF output 3 color patterns.
Model 91612 (16 patterns) shed only
1.86 1.88
DEPT. IZ AKRON, OHIO 443 6AL5 1.37 6E17 1.50
61Uß
61Yß 1.89
6X9
7F8 9.00 12BH7 1.67
$64.95
Model D612K in Kit form $49.95
6AM8 2.31 6EM7 2.37 Model DB11 (13 patterns) wired only
NAME 6AN8 1.91 6E117 1.70 $49.%
WRITE FOR FREE
I
ADDRESS
CITY STATE
I 6AQ5 1.43
1.49
6EW6
6EW7
1.50
2.51 VALUE PACKED CATALOG
Model DB116 (13 Patterns) in Kit Form
$39.95

''ENCLOSE j 6AQ8 2 YEAR WARRANTY ON BOTH TYPES

ZIP DSend Olson Cat

POSTAGE AND SALES TAX EDLIE ELECTRONICS, INC. 2700 -PP HEMPSTEAD TPKE., LEVITTOWN, N. Y. 11756
'.111,641144044414141644.a41 to gig 40,
CIRCLE NO 3.4 ON FREE INFORMATION CARD CIRCLE NO. 14 ON FREE INFORMATION CARD
102 POPULAR ELECTRONICS
 7400 TTL 5400 SERIES MOTOROLA CIRCUITS JAPANESE CIRCUITS
rVVU .LI r44L 1.U8 /4121 55 5400 1.00 5475 1.50 MC1741CG
7401 21 7448 1.15 74122
98 AN136 2.90 HA1312 4.05 STK056 11.35 747201P 6.40
.49 5404 1 25 5486 1.90 MC725P 1.50 MC1804P
7402 7450 98 AN203 3.75 HA1322 5.20 STK415 11.50 TA7203P 7.00
21 .26 74123 1.05 5410 1.00 5493 2.00 MC740L
7404 1.55 MC1806P .98 AN208 4.75 HA1339 5.20 TA7045M 3.50 TA7204P
21 7451 .27 74125 .60 5426 1.25 54100 1 80 MC790P 6.50
7405 1.50 MC1810P .98 AN210 3.10 LA1201 4.25 TA7054P
24 7453 .27 74126 81 5473 1.50 54LSO4 1.00 MC832P 3.05 TA7205P 6.50
7406 7454
.48 MC2053L .45 AN211 3.30 LA1364 4.70 TA7055P 5.50 TA78005M 2.50
45 41 74132 300 MC1004L 1.25 MC3004L
7407 45 7460 .22 74141
1.32 AN214 4.90 LA1366 6.00 TA7060P 1.85 TA78005P 1.95
1.15 C MOS MC1008L 1.25 MC3006P
7408 25 7472 .39 74150
1.44 AN217 3.30 LA1367 5.90 TA7061P 2.25 TA78012M 2.50
10 MC1010L 1.25
7409 7473
1
MC3007P 1.32 AN229 6.35 LA3301 4.85 TA7149P 400 TA78012P 1.95
25 45 74151 1.25 400146 40224E MC1011L
7410 20 7474 45 74153
29 1 20 1.25 MC3021L 215 AN234 5.75 LA4030 4.85 TA7063P 2.25 TA78015M 2.50
1.35 400246 29 402346 29 MC1036L 12.50 MC3021P
7411 30 7475 2.15 AN239 6.50 LA4031P 3.50 TA7074P 4.90 TA78015P 1.95
.80 74154 1.25 400746 29 40244E 1.50 MC1037L 12.50 MC3060L
7413 85 7482 1.75
2.65 AN241 3.20 LA4051P 4.65 TA7075P 4.90 TC9100P 12.00
74155 1.21 400946 58 402546 35 MC1352P 105 MC3062L 3.00 AN245
7416 43 7483 1.15 74157 1.30 6.50 T8A8105 3.50 747076P 4.55 UPC16C 2.50
4010A6 58 402646 149 MC1406CP 3.95 MC4024P 2.20 AN274 3.95 LD3080 4.00 TA7089P
7417 43 7485 1.12 74161 45 290 UPC20C 5.00
1
40114E 29 40284E 1.60 MC1468L 2.90 MC14501CP .31 AN277B 3.40 LD3120 3.10 TA7102
7420 21 7486 45 74164 1.65 401246 5.15 UPC41C 3.95
29 40294E 2.90 MC1469R 2.50 MC14502CP 1.18 AN288 4.80 LD3141 2.40 TA7106P 3.25 UPC48C
7422 50 7489 2.49 74165 1 65 401346 3.95
1
52 403046 .65 MC1510G 8.00 MC14507CP .82 AN328 4.05 M5112 540 TA7120P
7425 43 7490 .69 74166 1.70 40154E MC1514L 2.20 UPC554C 3.90
7427
1 25 40374E 4.50 450 MC14510CP 240 41.4343 3.90 M5115PR 4.80 TA7120P-C 2.20 UPC563H2 8.00
37 7491 1.20 74174 195 401646 40404E 2.40 MC1550G 150 MC14511CP
7428
65 2.76 BA511 3.50 M5155 2.85 TA7122AP 2.30 UPC566H 2.25
33 7492 .82 74175 195 40184E 10 40444E 150 MC1558 4.37 MC14512CP 1.92
7430 26 7493 82 74180 1.05
1
614521 3.95 SG613 5.40 TA7124P 1.85 UPC575C 4.10
401946 65 40474E 2.75 MC1595L 6.25 MC14519CG .94 HA1158 6.30 STK011 10.50 TA7146P 4.10 UPC1001H2 5.15
7432 31 7494 91 74181 3.55 40204E 404946 MC1596G MC14528CP
7437
1 75 75 3.31 174 HA1159 6.60 STK015 6.50 TA7150P 4.55 UPC1020H 5.50
47 7495 91 74191 50 40214E 50 40504E MC1723CG 125 MC4044P 4.80
7438
1
1 75 HA1202 3.10 STK025 12.50 147153P 6.90 UPC1025 5.50
40 7496 91 74195 1.00
7440 HA1306W 5.20 STK032 14.20 TA7200P 6.25
21 74100 125 74197 1.00
7441 1.10 74107 49 74298 1.30 POSITIVE
VOLTAGE
MISC CIRCUITS REGULATORS IC's ON THE MOVE
74L SERIES TTL
BC184L 60 LM309K 1.95 SN15844N 55 LM340K-5 1.95 BBD BUCKET BRIGADE DEVICE
74L00 33 74LSO4 45 74LS113 98 CA3001 .75 LM351AN 70 SN 15946 .55 LM340K-6 1.95 MM3001 19.50 MN3002 11.70 MM3003 9.45
74L10 33 74LS10 39 74LS138 1.89 CA3005 .80 LM741CP .40
SN158097N .60 LM340K-8 1.95 HALL IC DN834
: 1.25 DN837 1.50
74L30 33 74LS20 39 74LS174 250 CA3006 1.10 LM1458M .65
SN72560P 4.50 LM340K-12 195 DN835 1.35 DN838(NEW)
74L42 1.50 74LS51 39 74LS386 550 CA3018 1.60 MFC9020 1.15
SN727410N .85 LM340K-15 1.95 SN76001 1.75 SN76002 1.95
74L86 69 74LS74 65 745153 225 CA3018A 1.60 MR995A 1.05
SN72741C 45 LM340K-18 1.95 PLL02A MIDLAND PHASE LOCK LOOP
74LS00 39 1200
741.5112 65 740387 195 CA3026 2.15 MSC9967P1 50 SN72748P .49 LM340K-24 1.95
CA3035 2.45 N5558 .55 UA703C .95 LM340T0-5 1,75 MICROPROCESSOR CHIPS
CA3039 1.35 N85988 5.00 UA709C .40 LM340T0-6 175
74H00 TTL CA3058 1.90 NE555V .45 USF7733393 2.40 LM340T0-8 14044
75 1 3.25 2102
2.50 MM5013 325
CK707P .45 PA771131 .45 995879 6.50 LM340T0-12 1.75 C17024 19.95 C2708
74H00 33 74H11 33 74H53 39 1.15 PL994551
95.00 8008 19.95
C5134J .45 996079 12.50 LM340T0-15 1.75
74H01 33 74H20 33 74H55 39 C5135J 1.20 RC14370B .35 998979
2101 6.95 C47024 19.95 80804 29.95
9.00 LM340T0-18 1.75 MK4200 P -11 4096x1 Bit Dymanic Rem
74H04 .33 74H21 33 74H73 59 C5136 1.25 SC9962P .70 936-5D 1.10 LM340T0-24 1.75 9.95
74H05 35 74H30 33 74H74 59 IC3(GE) 1.50 SC9966P 1.25 9313DC C5101 -3 1024 Bit (256x4) Static C -Mos Ram 4.50
1.20
74H10 33 74H40 33 74H76 60 LM301AN NEGATIVE MC14514 4 Bit Latch 4 to 16 Line Decoder 4.25
35 SN15830N .50 93L280C 2.75
REGULATORS CALL OR WRITE FOR FURTHER INFORMATION.
AVAILABLE SPEC'S AVAILABLE

ELECTROLYTIC HOBBY SPECIALS PACE /PATHCOM PART S'S

CARBON RESISTORS
CAPACITORS 5 Pc s Per Vale
Minimum YOU TEST 'EM SAVE BIG MONEY 130079 4.00 P20-0123 2.75
Power Pac 100 Asst. (includes Case T03.1066 $2.99 1300821 .65 P20-0131 2.50
2.2MF50 AXIAL LEADS 10220. 102021 13-0122 1.75 P20-0141 3.00
15 QUANTITY Transistor/ 100 Asst (includes Case T05.
3.3MF10 AXIAL LEADS .15 PRICING 5 -25 $1.99 83-0005 2.00 P20-0142 3.00
30 -95 100 -495 Diode Pac 1039. 1018. D07. 0041)
3.3MF10 NO POLARITY .15 14w5% .06 .05
83-0007 2.50 P20-0139 .43
.04 C Pac 100 Asst (includes 14 E 16 Pin)
10M F25 AXIAL LEADS .15 1/2w5% .08 .06
I
$3.50 83-0008 2.00 P20-0154 6.00
.07 Resistor Pac 50 Asst. (Assorted values) $1.50
10M F50 AXIAL LEADS .15 STANDARD RESISTANCE VALUES 83-0015 3.00 P20-0155 2.50
10MF150 AXIAL LEADS Mos Fet Pac 10 Asst. (many top as Case 1072) $0.99 P20-0005 3.00 P20-0161 4.00
.20 OHMS
25M F35 SCR Pac 100 Asst. (similar to'C103 Series) Case to 92. $4.00 P20-0016 .40 P20-0177 2.75
AXIAL LEADS .15 10 270 820 4.7K 27K
30MF25 AXIAL LEADS VR10 -100V. I.400MA. IGT:200MA P20-0034 .85 P20-0176 2.85
.15 22 300 910 5.1K 33K
47MF25 RADIAL LEADS .15 47 330 1.0K 47K
P20-0037 .85 P20-0191 .72
6.8K P20-0045
47MF50 RADIAL LEADS .20 51 470 1.5K 7.5K 100K ZENER DIODES 2.00
100MF16 RADIAL LEADS .15 100 8 / Watt 10%
1/: 30 each UP TO 33V. P20-0073 2.75
510 2.2K 8.2K 330K
100MF25 RADIAL LEADS
500MF50 AXIAL LEADS
.20
.60
150
220
560 2.7K 10K 1 O GREATER THAN 33V CALL FOR PRICING P20-0093 2.50
680 3.3K 15K
1000MF35 AXIAL LEADS .65 240 750 3.9K 22K
POPULAR JEDEC SEMICONDUCTORS

JAPANESE TRANSISTORS * CB. AUDIO, INDUSTRIAL 1N34 .25 2N918 .60 2N2218 .25 2N29064 .30 2N3646 .14 2N42204 .45
1N60 .25 2N930 25 2N22184 .30 2N2907 .25 2N3730 2.50 2N4234 .95
2S452 1N270 .40 2N956 .30 2N2219 .25 2N29074 .30 2N3731 3.75 2N4400 .16
60 2SC206 1.00 2SC774 1.75 2SC1173 .95 2SD77 1.00
2S4316 95 2SC240 1N914 .10 2N960 .90 2N22194 .30 2N2913 .75 2N3740 1.00 2N4401 .16
1.10 2SC775 2.75 2SC1175 .65 25D81 3.25
2SA473 75 2SC291 .65 25C776 2N962 .95 2N2221 25 2N2914 1.20 2N3771 1.75 2N4402 .16
3.00 25C1209 .55 25088 1.50 2N173 1.75 2N967 .95
2S4483 195 2SC292 3.00 28C777 4.00 2SC1213 .75 25D118 3.25
2N22214 30 2N29164 3.65 2N3772 1.90 2N4403 .20
254489 2N174 3.50 2N1136 1.75 2N2222 .25 2N3019 .50 2N3773 3.00 2N4409 .16
80 2SC320 .75 2SC778 4.00 2SC1226A 1.25 25D130 1.25
2S4490 .70 2SC352 .75 2N178 .90 2N1142 2.25 2N2222A .30 2N3053 .30 2N3819 .40 2N4410 .16
2SC781 3.00 2SC1237 4.50 250141 2.25
2S4505 .70 2SC353 .75 2SC783 1.00 2SC1239 4.00 250151 2N327A 1.15 2N1300 1.00 2N2223 1.00 2N3054 .70 2N3823 .70 2N4416 .75
2.25 2N334 1.20 2N1301 1.10
2S4564 .50 2SC371 .70 2SC784 .70 2SC1243 1.50 250170 2.00 2N2270 .40 2N3055 .75 2N3856 20 2N5081 .30
2S4628 .65 2SC372 2N336 .90 2N1302 1.25 2N2323 1.00 2143227 1.00 2N3866 .85 2N5064 .50
.70 2SC785 1.00 2SC1293 .85 250180 2.75
2S4643 .85 2SC394 .70 2SC789 1.00 2SC1306 4.75 250201 1.95
2N3384 1.05 2N1303 .70 2N2324 1.35 2N3247 3.40 2N3903 .16 2N5130 .20
2S4647 2.75 2SC458 2N3988 1.50 2N1304 1.25 2N2325 200 2143250 .50 2N3904 .16 2N5133 .15
.70 2SC793 2.50 2SC1307 5.75 25D218 4.75
2S4673 .85 2SC460 2N404 .75 2N1305 .75 2N2326 2.85 2N3375 6.50 2N3905 .16 2N5138 .15
.70 2SC796 3.15 2SC1308 4.75 25D235 1.00
254679 3.75 2SC478 2SC797 2N443 2.50 2N1306 1.35 2N2327 3.80 2N3393 .20 2N3906 .16 2N5198 3.75
.80 2.50 2SC1317 .60 250300 2.50
284682 .85 2SC481
2N456 1.30 2N1307 .75 2N2328 4.25 2N3394 .17 2N3925 3.75 2N5294 .50
1.85 2SC798 3.10 2SC1318 .70 25D313 1.10
254699 1.30 2SC482 2N5014 3.00 2N1308 1.50 2N2329 4.75 2N3414 .17 2N3954 3.50 2N5296 .50
1.75 2SC799 4 25 25C1325 4.95 253315 .75 2N5084 .45
2S46994 1.45 2SC491 2.50 2SC802 3 75 2SC1327 .70 25D316 2N1309 .90 2N2368 .25 2N3415 .18 2N39544 3.75 2N5306 .20
2.50 2N555 .75 2N1552
2S4705 55 2SC495 1.10 2SC803 4 00 2SC1338 1.75 25D317 1.25 3.25 2142369 .25 2143416 .19 2N3955 2.45 2N5354 .20
2S4815 .85 2SC497 1.60 2SC815 .75 2SC1346
2N6524 1.25 2141554 1.25 2N2484 .32 2N3417 .20 2N3957 1.25 2N5389 .20
.80 2S0318 .95 2N677 6.00
254816 .85 2SC502 1.50 2SC828 .75 2SC1347 .80 25D325 1.25
2141557 1.15 2N2712 .18 2N3442 1.85 2N4036 .75 2145400 .40
2SC515 .80 2SC829 2N706 .25 2N1560 2.80 2N2894 .40 2143553 1.50 2N4037 .80 2N5401 .50
.75 2SC1364 1.50 250341 .95
25622 .65 2SC517 4.25 2SC830 1.60 2SC1377
2N706B .75 2N1805 .35 2N2903 3.30 2N3563 .20 2N4093 .85 2N5457 .35
5.50 25D350 3.25 2N711 .90 2N1613
25654 .70 2SC535 .75 2SC838 .70 25C1383 .75 250352 .30 2N2904 .25 2N3565 .20 2N4124 .16 2N5458 .30
.80 2N711B 1.10
2SB56 .70 2SC536 .65 25C839 2N1711 .30 2N29044 .30 2N3638 .20 2N4126 .16 CIO3Y .25
.85 25C1384 .85 25D380 5.70 2N718 4.10
2SB77 .70 2SC537 .70 25C922 .55 25C1409 .25 2N1907 2N2905 .25 2N3642 .20 2N4141 .20 C106B1 .50
1.25 25D389 .75
2N7184 .30 2N2060
258128 2.25 2SC563 2.50 2SC929 .70 2SC1410 1.25 250390 .75 1.85 2N29054 .30 2N3643 .20 2N4142 .20
258152 4.50 2SC607 1.25 2SC930 .65 2SC1447 1.25
2N7204 50 2N2102 .40 2N2906 .25 2N3645 .20 2N4143 .20
256173 .55 2SC614 3.80 25C938 .65 25C1448 1.25 2SF8 3.00
258175 .55 25C615 3.90 2SC943 1.50 2SC1449 1.30 2SCF8 3.50
256178 1,00 2SC616 4.15 2SC945 .65 2SC1475 1.50 2SCF6 1.25 SILICON
2513186 .60 2SC617 4.25 2SC959 3.15 2SC1507 1.25 HEPS3001 3.25 HARDWARE IC SOCKETS
2SB187 .60 2SC620 UNIJUNCTIONS RECTIFIERS
.80 2SC960 2.75 2SC1509 1.25 JSP7001 .75
258235 7.00 2SC627 1.75 2SC984 1.50 25C1589 1.25 MRF8004 3.00
258303 .65 2SC642 3.50 2SC996 4.90 2SC1674 1.75 MPS8000 1.25 2N2160 .65 MU4892 .50 Nylon Screws. Nuts 6 Rivets (Complete Kit, 50 pc'a) 1.99 10 100
256324 1.00 25C643 3.75 2SC1010 .80 2SC1675 1.75 MPS8001 1.25 2N2646 .45 MU4893 .50 Trans H/W Mica, Bushings 8 Screws For For
2SB337 2.10 2SC644 .70 2SC1012 .80 25C1878 5.50 MPSUO2 .50
2N2647 .55 MU4894 .50 Case 103, 1066 & 10220 (Specify Type, 10 Sets) 1.00 IN4001 80 5.00
258367 1.60 2SC681 2.50 2SC1013 1.502SC1679 4.75 MPSU31 4.00 2N4851 .75 2N6027 55 MK20 T03 Complete Mounting Kit 5/.99 IN4002 .70 8.00
256370 .65 2SC684 2.10 2SC1014 1.502SC1756 1.25 SK3047 3.75 2N4852 .75 2N6028 .70 MK25 TO66 Complete Mounting Kit 5/.99 IN4003 .80 7.00
2SB405 .85 2SC687 2.50 2SC1017 1.502SC1760 2.15 SK3048 3.25
2144870 .50 D5E37 35 IC Socket 8 Pin TO5 Pkg. of 2 1.o0ee. IN4004 .90 8.00
256407 1.65 2SC696 3.00 2SC1018 1.50 2SC1816 4.50 5113049 4.75 2N4871 .50 MU10 .35 IC Socket 10 Pin To5 Pkg. of 2 1.22sa. IN4005 1.00 9.00
2S8415 .85 2SC699 4.75 25C1030 4.75 2SC1908 .70 SK3054 1.25 MU4891 .50 MU20 40 IC Socket 14 Pin OIL Pkg. 01 1 .25ea. IN4006 1.10 10.00
258461 1.25 2SC710 .70 2SC1051 2.50 2SC1909 4.75 25K19 175 IC Socket 16 Pin DIL Pkg. of 1 .27ea. IN4007 1.20 11.00
258463 1.65 2SC711 .70 2SC1060 .75 2SC1957 1.50 2SK30 1.00
256471
258474
1.75
1.50
2SC712 .70 2SC1061 1.65 2SC1973 1.50 2SK33 1.20 NEW -TONE ELECTRONICS
25C713 .70 2SC1069 3.50 25C1974 4.90 25K41 1.75
258476 1.25 25C731 3.00 25C1079 3.75 2SC1975 4.90 3SK22Y 2.75 PO BOX 1738A
2SB481 2.10 2SC732 .70 2SC1080 3.75 2SC2028 1.10 3SK40 2.75
259492 1.25 2SC733 .70 2SC1096 1.20 2SC2029 4.75 3SK45 2.75
BLOOMFIELD, N.J. 07003
258495 .95 2SC735 .70 2SC1098 1.15 2SC2074 3.00 3SK49 2.75 PHONE: (201) 748 -8171, 6172, 6173
2SB507 .90 2SC739 .70 2SC1115 2.75 4004 3.00
2SB511 .70 2SC715 .70 2SC1166 .70 25D45 2.00 4005 3.00
258531 3.00 2SC758 3.00 2SC1167 4.25 2SD65 .75 40080 1.25
Thank you, for your Interest and response to Now -Tones
2S8556 3.50 2SC762 1.90 2SC1170 4.00 25D68 .90 40081 1.50
2SB135 95 2SC773 .85 25C11728 4.25 2SD72
N.J. residents add 5% safes tax, minimum order $5.00. Phone Orden Welcome
1.00 40082 3.00
AN orders add $1.00 Postage $1.50 Canada Deslen Write or Phone for Discount Prices
ALL PARTS GUARANTEED PARTIAL LISTING - WRITE FOR FREE CATALOG

CIRCLE NO 31 ON FREE INFORMATION CARD

JULY 1977 103
TREASURE FINDERS HOME ENTERTAINMENT FILMS INVENTIONS WANTED

SERIOUS COIN SHOOTERS Semtech's solid -state - MIDSUMMER FILM SALE Ali vs. Inoki (The Boxer vs.
the Wrestler or Karate vs. Ali) Super 8 B &W SPECIAL $6.95
- INVENTORS: Manufacturers Need New Products. Free
"Recommended Procedure," by a creative fee -based
METL-SENSOR pin points ALL metal objects, yet defines
invention service conpany. Washington Inventors Service,
the target before you dig. FOR FREE literature write
Semtech Corporation, 652 Mitchell Rd., Newbury Park,
ea PPD. Wrestling featuring wrestlers like Jim Londos &
Joe Savoldi - -
set of 2, $6.95 ea PPD (5 bouts to a reel
Buy singly or as a set! Add to or start a
- 422 -T Washington BJilding, Washington, D. C. 20005.
Calif. 91320. $2.00 off per reel)

TAPE AND RECORDERS

World Series Official Film collection: Your choice of 200'
Super 8 B &W $6.95 ea or Color $16.95 ea. 1969 -1975
each a separate reel. Indicate exact year. Send for
- -
Columbia catalog, $0.85; Universal 8 catalog, $0.75; Sport-
lite forms $0.35. SPORTLITE, Elect -7, Box 24 -500, Speed -
RENT 4-Track open reel tapes -free brochure. Stereo -
way, Indiana 46224.
Parti, P.O. Box 7, Fulton, CA 95401.
WE WILL BEAT any price sheet in America. Featuring RECOGNITION... FINANCIAL
TDK, MAXELL, and others. Tape World International, 220 PERSONALS REWARD...OR CREDIT
Spring St., Butler, PA 16001. FOR "INVENTING IT FIRST' MAY BE YOURS!
8 -TRACK and CASSETTE BELTS
guarantee. Long wearing. Free Catalog
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-- MAKE FRIENDS WORLDWIDE through international
'If you have an idea for a new product, or a way
to make an old product better, contact us, "the
order. PRB Corp., Box 176, Whitewater, Wisconsin 53190. correspondence. Illustrated brochure free. Hermes -Verlag, idea people" We'll develop your idea, introduce it to
LP's, TAPES, Current, Cutout, Imports, Catalogs $1
Box 110660/Z, D -1000 Berlin 11, Germany. industry, negotiate for cash sale or royalty licensing.
WARTS. Vergo`® Cream is painless, safe, easy, gentle. Buy Write now without cost or obligation for free
Beatles LP -Tape Sale. NERI, Box 268-PE, Lawrence,
Vergo& at better pharmacies. 'information. Fees are charged only for contracted
Mass. 01842.
services. So send for your FREE "Inventor's Kit." It
has important Marketing Information, a special
P.O. Box 4430C Santa Clara, CA 95054 "Invention Record Form" and a Directory of 1001
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INTEGRATED CIRCUITS ca001 7100 25 20
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c01002 25 7404 33
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7190N 15 74L9221N .95 LM1301 20 010i6 10 75 '25
095
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L4112N Uprason,p Trans 6.0 °G1pp0,, FluorücenlGF 1.75
14920 45 74L958M 21.0 LM1310 2.75 ]II II
8096 .75 Ultrasonic speaker 1.00
74938 9 LM149 59 CD1030 3 vni
1MO39090N LED Be 1539332 36ÉNit0BIl '32
MADE $40,000.00 Year by Mailorder! Helped others make
MasMasher/
71958 75 LINEAR 101800 .15 [04035 t0898B .75 89 I
71100N .90 CA3045 0 101812 7.9 404011 1.35
125 BMOM89ROOC16a S0 6.0 MM5865 Stopwatch Dinar 9.00 7520CMneip60óIS 90
money! Free Proof. Torrey, Box 318 -NN, Ypsilanti,
8109
141070 39 CA3046 .95 101889 390 C,04a2 95
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FREE CATALOGS. Repair air conditioning, refrigeration.
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Tools, supplies, full instructions. Doolin, 2016 Canton,
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088,a'ü 518 Vntl OC 10 S158Ha TV GAME 058PE Dallas, Texas 75201.
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3.0 MAILORDER MILLIONAIRE helps beginners make $500
741630 1.35 W11X NE5697V 1.25 N625123 1.0 erlinparls b
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9950

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74100 1.15 9M378 I.35 700 1.0 04076 1.75 2112-2 7.0
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333 North Michigan, Chicago 60601.
14192N 125 03201-5 25 ]8105 40 25138 270 29.0 V0 00 ma iranslorml' 1,25
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75108 1.75 5 Re81170R6 12V 29 ma wall plug 295
60 MJ205-15 7,30 145320 5.95 V0W interlace bawd kit 149.95

. you $500 to $5 Mil ion cash. Free report! Credit 4K7, 333
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North Michigan, Chicago 60601.
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ELECTRONIC FACTORY
9570N 28 M340T-B i.70 g100LJ V lo f 7.40
91 W40i-12 50459 4.0 cnue0 w/moduM 2.95
7115130 1.70 58153710 5.0 804584 Kit 599.00 041003 at m148
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Investment unnecessary, knowledge not required,

sales handled by professionals. Postcard brings
Not a Cheap Clock Kit $17.45 Function Module Card Kit Hobbiest Electronics Course facts about this unusual opportunity. Write today!
Includes everything except case. 2 -PC Converts any frequency counter into 31/2 Beginning course in practical electronics.
Barta- DT, Box 248, Walnut Creek, CA 94597.
boards. 6 -.50" LED Displays. 5314 clock digit DVM, digital thermometer, pulse no theory. Lab experiment format. 12 les-
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full instructions. Same clock kit with .80" Complete kit minus power supply. $25.00 $10.00 per lesson
displays. $22.75 HOW TO MAKE $2000 WEEKLY at home using other peo-
Plexiglas Cases Black or white VOLUME SPECIALS , 180
60 Hz Crystal Time Base ple's money. Guaranteed. Free Details. Richlieu, Box
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Kit $4.75 Converts digital clocks 25357, Dept. F7, Houston 77005.
9005365 010,043 2.10 1 40
2102-1 500 06 7K NAM 1.80 1.30 from AC line frequency to crystal time NEW LUXURY Car Without Cost. Free Details! Codex -ZZ,
Digital Temperature Meter Kit 40411 -3 150 NS OK PAM 8.00 5.75 base. Outstanding accuracy. Kit includes:
Box 6073, Toledo, Ohio 43614.
Indoor and outdoor. Automatically
Momentary Pushbutton switch 50 .29 PC board, MM5369, crystal, resistors,
switches back and forth. Beautiful. 50"
Other parts also 2091407e capacitors and trimmer. MAKE BIG MONEY in spare time selling: Tubes, Antennas,
LED readouts. Nothing like it available. Speakers, Test Epuipment, Lite Bulbs, Hi -Fi, etc. No invest-
Needs no additional parts for complete, 30 MHz Frequency Counter Kit Volt/ohm Probe ment. Free information: Allied Sales, Pimento, IN 47866.
full operation. Will measure -100° to (812) 495-6555.
Crystal time base. Covers audio, amateur Batt. oper. AC /DC to 125 V. 2 pos. volt.
+200 °F, air or liquid. Very accurate.
and CB band. 6.5" digits, prescalable with and 2 neg. volt. plus continuity. Stainless MECHANICALLY inclined individuals desiring financial in-
Complete instructions. $39.95
PC board and full instructions. $55.00 steel, pocket size. comp. assem. $34.95 dependence operating Small Electronics Manufacturing
Fully wired and tested. $75.00
Variable Power Supply Kit Business without investment. Write: Marks, 92 -K7 Brighton
0-12 VDC @1/24 7.1% line, load regulation.
Digital Thermometer $65.00 11th, Brooklyn, New York 11235.
Stopwatch Kit $26.95 General purpose or medical 32 °- 230 °F.
Remote sense capability. Constantvoltage/
Full six digit battery operated. 2 -5 volts. Disposable probe cover ±.2° accuracy. WEEKLY! IMMEDIATE, GUARANTEED income
$500.00
circuit limit can be modified for other stuffing envelopes. FREE Supplies! Interested? Send 25
3.2768 MHz crystal accuracy. Times to Completely assembled w /compact case.
V/I ranges. Complete with board and cents stamp. Profios, B725-PE7, Beten, N.M. 87002.
59 minutes, 59 seconds, 99 1/100 hrs.
transformers. $24.00 Times standard, split and Taylor. 7205
2.5 MHz Frequency Counter Kit FREE REPORT: Ehg Money In Mail! Transworld -9K, Box
chip, all comporents minus case. Full
As low as 10 Hz .6-.50" digits with PC 6226, Toledo, Ohio 43614.
1977 IC Update Master instructions. White or black plexiglass
Manual Brand new. Complete inte- case. $5.00 board and full instructions. $40.00 HOW TO BORROW $25,000 interest-free!... Indefinitely!
grated circuit data selector from all manu- Free Report: Executive -PE7, Box 368, Buford, Georgia
facturers.1234 page master ref guide to COSMAC 'ELF' Auto Clock Kit $15.95 30518.
the latest IC's including microprocessors RCA CMOS Microcomputer DC clock with 4 -.50" displays. Uses Na-
and consumer circuits. 17,000 cross CDP1802 CD S2150 Users Manual 57.50 tional MA1012 module with alarm option.
references for easier sourcing of hard to Complete kit of parts to build the "ELF" Crystal time base PC boards and full in- MAGNETS
get parts. Special pricing: $24.95, with including CDP1802 and users manual as structions. Add $3.95 for a beautiful
free update service thru 1977. Domestic listed in August '76 Pop. Elect. minus dark gray case ready to install. This is
postage all $2.00. Foreign $6.00. power supply and board. $92.00 the best value available anywhere! MAGNETS. All types. Specials -20 disc. or 10 bar, or 2 stick
or 8 assorted magnets. $1.00. Magnets, Box 192 -H Ran -
TERMS: $5.00 min. order U.S. Funds. Calif residents add 6% tax. dallstown, Maryland 21133.
FREE: Sendfor your copy of our 1977
BankAmericard and Master Charge accepted.
OUEST CATALOG. Include 130 stamp.
Shipping charges will be added.
CIRCLE NO. 40 ON FREE INFORMATION CARD
104 POPULAR ELECTRONICS
 Money
Radio Hut
back guarantee. NO COD'S. Texas
residents add 5% sales tax. Add 5% of order
Memorex computer boards
with IC's, diodes, transistor,
etc. 5 Boards containing
BRIDGE
RECTIFIERS
RESISTORS
Over 50,000,000
in stock
'330 ohm 22K ohm

for postage and handling. Orders under $15.00 100 - 200 IC's Amp
6
10 Amp
50V
50V
1.10
1.25
470 ohm
"680 ohm
27K ohm
33K ohm
add 75 cents. Foreign orders add 10% for ONLY $4.25 1K ohm 39K ohm
postage. 25 Amp 50V 1.39 1.2K ohm 43K ohm
22K ohm 47K ohm
For your convenience, call your BankAmericard 3.3K ohm 82K ohm
or Master Charge orders in on our Toll Free Watts MK 5005
Line: 1- 800 -527 -2304. Texas residents call col- UNSCRAMBLER KIT 4.7K ohm 100K ohm
4 digit counter /latch 6.8K ohm 150K ohm
lect: 1-214-271-8423.
decoder; 7 segment for all Scanners 10K ohm 220K ohm
20K ohm
master charge P. O. Box 64783P
nul output only. 24 pin Tunes easily
Dallas, Texas 75206 BANKAMERICARD
dip with specs. '1 /8W only
Full instructions included "1/2 W only
uvliv-n,v b ,. $ 8.00 EACH
All resistors are P.C. Lead but are
Easy to install
not pull of fs.
PLASMA DISPLAY KIT SPECIAL DEVICES 100 min. order for each value
31/2" x 31/2" x 11/2"
82S23 2.19
Kit Includes: 12 digit display .4" Charac- 2513 10.00 Only $19.95 NO MIX 100/.99
ter Power supply for display MK4102 -1 .99
above Complete specs for
hookup.
REGULATORS READOUTS
PROJECT CASES
Line cord Not Included. ONLY $ 3.95 Small Med. Large 7805 7818
51.50 52.00 52.75 7806 7824
7808 7905
W-03/4" W4-7/8" W-7"
H-1 -7/8" H-3-1/2" H-4" 7812 7912
All cases have a sloped front, white 7815 7915 FND70 .4 "C.C. .59
with black wrinkle finish.
Your Choice $ .95 F N D800 .8 "C.C. 1.69
VARIABLE POWER SUPPLY KIT NO. 1 TI 6 digit array C.C.
WATERGATE SPECIAL *Continously variable from 5V to 20 V 3/1.00
*Excellent regulation up to 500 mil. MAN 8 .3 "CA Yellow
Telephone Relay automatically starts and *4400 Mfd of filtering .89
stops tape recorder. No batteries required. *Drilled fiberglass PC Board LT767 .7" C.C. 4 digit
One hour assembly
Kit complete with drilled P.C. Board. stick $ 3.95
*Kit includesall components
Parts and Case ONLY $ 10.95
*Case Included Ni -Cad Batteries
ONLY $10.95
Kit includes
CLOCK KIT VARIABLE POWER SUPPLY KIT NO. 2 4 Brand New Size "AA"
- LT701 clock module
Same as above but with amp output, also with case. 1 Ni -Cads ONLY $4.50
Power Supply
Punched Case ONLY $13.95
12 or 24 hour operation BATTERY CLIPS TRANSISTORS - PC BOARDS
DIODES 4 digit PCB o,. 1
73 L/800 of 807 2.50
Complete Standard 9V battery clip with 'MJLI 103 3/I.00 6 digit PCB loi F ND800 or 807 3.50
except for line cord 4 -1/2" tinned leads. 25/$1.00 MJ3001 .3 0 1
4 digit PCB for DL707 1.50
7N22:7 6'1.0 0
LT701 E 12 hour clock N2 36'1 6.1 .00 6 digit PCB for DL707 2.00
ONLY $ 14.95 *** * ** N2905 4.1.00
.

LT701 G 24 hour clock

TTL
* '7N290/
2 N3906
1S /I .00
6/1.00
2 4

6
digit PCB for FND503 or 510
digit PCB for FN0503 or 510
2.00
3.00
HARDWARE 7400 17 74 73 21
2 N4400 6/1.00 4 digit PCB for 0L747 2.50
7401 .17 2 N4443 SCH 3/1.00 6 digit PCB for DL747 3.00
7474 .35
New, includes 2 -56, 4 -40, 6 -32 and 8 -32 7402 .17 7475 55 I N4004 1 5 .00
/1
4 digit PCB for DL727 or 728 2.00
7403 17 7476 35 I N400 / I O/1 .00
screws and nuts. A very usable selection. 74H04 N4 N9 )20/1.00 6 digit PCB for DL727 or 728 3.00
.25 7480 45 1 1 4 8 11 1 4

7404 17 3 N70 VHF Ore amp .80 4 digit PCB for FNO359 or 70 75
pound $1.50 7483 76
I
1

7406 .25 7485 89 040C1 Power Dart -8/1.00

1 pound $2.60 7408 .r7 7486 35 NOTE: All PC Boards are multiplexed
7409 .1 7 7490 71 *House numbered
7410 -17 7491 and P.C. Lead for adding additional digits.

=
71
L S CMOS SALE 7411 .25 7492 .71

74LS00
74LS02
25
25
4020 .85 4046 .90
7413
7420
7421
.45
.17
-17
7493
7494
67
.90
LINEA RS 60 Hz L()()K
CD4000 .16 CD4040 1.00 7495 71 FM 301 30
74LSO4 30
CD4001 .16 CD4041 .69
7423
7425
.35
.27
7496
74100
.85
96
LM30/ 30 Crystal Time Base Kit _ Kit
74LS08 .25 LM309K 95
CD4002 .16 CD4042 .59 7426 .25 74121 31 LM311 85 enables a MOS clock circuit to op-
74LS10 .25 7427 74123 61
CD4007 .16 CD4043 .60 7430
.1 7
44
LM377 1 85 erate from a DC power source. Ideal
74LS11 .32 .25 74125 LM38018 pinl 75
74LS20 31
CD4009 .45 CD4044 .59 7432 .30 74141 71
LM3900 30
for car, camper, van, boat, etc.
CD4010 .45 CD4047 .59 7437 .35 74145 97
74LS21 LM710 25
.33
CD4011 .16
7438 .35 74151 71 60Hz output with an accuracy of
74LS22 33 CD4049 .35 7440 .17 74153
LM711 25
CD4012 .16 CD4050 .35 7442
81
LM 723 40 .005% (typ.) Low power consump-
74LS27 .30 6D 74154 97
74LS30 CD4013 .29 CD4051 .90 7443 60 74161 91
LM741 25 tion 2.5 ma (typ.). Small size will
31 LM 748 25
74LS32 33 CD4014 .75 CD4053 .90
7444
7446
.65 74163 1.05
1.05
NE553 1.95 fit most any enclosure. Single MOS
.85 74164
74LS37 40 CD4015 .75 CD4056 1.00 7447 .81 74174 91
NE555 .40 IC oscillator /divider chip 5 -15 volts
NE556 95
74 LS38 35 CD4016 .29 CD4058 .90 7448 .81 74175 1.40
NE565 95
DC operation.
7450 .20 74180 76
74LS74 49 CD4017 .80 CD4060 1.00 7451 17 74181 2.25 NE566 95
ONLY $ 5.95
74 LS90 .85 CD4018 .80 CD4066 .69 7453 17 74191 1,20
NE567 1 10

74LS132 90 CD4019 .39 CD4069 .30 7454 .17 74192 1.20

1458
RCA3043
49
75
2 for $10.00
7470 .35 74193 95
74LS138 89 CD4021 .90 CD4071 .16 7472 .21 74195 65 75491 .30
74LS139 CD4022 75492 .30
.89 .90 CD4076 .99 RADIO HUT GUARANTEE
74LS155 90 CD4024 .70 74C04 .29
74LS157 1 .00 CD4025 .19 74C107 .29 ORDER BY PHONE. Charge your If you are not satisfied with any of
74LS162 1.39 CD4027 .39 CD4116 .39
order to BankAmeri card or our products NO MATTER WHAT
74LS163 1.39 CD4028 .75 CD4507 .40
74LS175 09 THE REASON we offer you a full
1
CD4029 .99 CD4512 .50 Master Charge
74LS193 1.09 money back guarantee if the prod-
CD4030 .16 CD4516 .85
74 L S 258 1.09
CD4034 2.30 CD4518 .85
USE OUR TOLL FRE E WATTS uct or products are returned within
74LS367 70
CD4035 .99 CD4520 .85
74LS368 70 1- 800 -527 -2 304 i 14 days after you receive them.

CIRCLE NO 41 ON FREE INFORMATION CARD

JULY 1977 105
r 1 BOOKS AND MAGAZINES

World's Lowest FREE book prophet Elijah coming before Christ. Wonderful

IC Prices
bible evidence. Megiddo Mission, Dept. 64, 481 Thurston

For Rd., Rochester, N.Y. 14619.

POPULAR ELECTRONICS INDEXES For 1976 now avail-
able. Prepared in cooperation with the Editors of "P/E,"
* SPECIAL PRICES * this index contains hundreds of references to product
MEMORIES
Rama
745200 2.95
74109
74116
74123
74141
.30
1.50
.45
.80
*
*
740174
745175
745181
740197
2.05
2.05
2.95
2.20
*
CMOS
4001
0002
4006
.16
.18
.90
faster tests, construction projects, circuit tips and theory and is
an essential companion to your magazine collection. 1976
Edition, $1.50 per copy. All editions from 1972 onward still
2102 1.50 * 74145 .75 740257 1.50 4007 .18 available at the same price. Add 5.25 per order for postage
21021 1.70
74150 .6o * 4008 .70
Prom.
82523/5123
825129
Others
1.95
3.25
*
74151
74152
74155
74157
.80
.90
.80
.80
HIGH SPEED
741100
74o01
74804
4011
4012
1013
4015
.18
.18
.30
*
*
* service and handling, $.50 per copy, foreign orders. INDEX, Box
2228, Falls Church. Va. 22042.
TECHNICAL MANUALS -
Ameco, Arrl, Cowan, Gilfer,
TMS 3409 2.00 74160 .75 74810 4016 .ss * Rider, RCA Radio Callbook, Sams, Tab, T.I. Postage 35
MM 5013 1.50
74161 .75 * 74811 4019 .70
NS 5280
NS 6619
1.50
2.00 74163 .75 * 74640 4020 .90 cents bk, ppd. Five. Madison Electronics, 1508 McKinney,
MM 002611 3.25 74165 .80 741151 4021 .95 Houston, Texas 77002.
TTL 74173 1.25 741152 4023 .16 *
* 74174 .75 74674 4025 .20 * BACK ISSUE MAGAZINES. 1890 to 1976. Free list. Send
*
USE
7400 .12 746103
7402 .14
74175 .75
746106
4027 .40 stamped envelope to Everybody's Bookshelf, Dept. PE, 317
.14 *
74177 .70 4026 00
7403
74160 .80 4030 .35 West 6th, Los Angeles, CA 90014.
7404 .16 LOW POWER
74181 1.50 4040 .95
7407 .20 SCHOTTKY
74191 .65 4042
7410 .12 * 74192 .70 * 741500 .29
4043
.60
.75
FREE! Consumer Service Division Catalog. In-
*
ZIP
7416 .25 74L502 .29
74193 .70 4044 .70
7420 .12 * 74194 .85 741$06 .29
4049 .35 * cludes a wide variety of products associated with

-
7427 .25 741510 .29
74195 .88 4050
7437 .20
74198 1.25
74LS27
.35
the special interests of readers of Ziff -Davis mag-
ll 7138 .20 * * 74LS73
4066
7440 .12 * 9602
9300
.50
.75
741575 .55
4068
4071
.35
.16 azines PSYCHOLOGY TODAY, POPULAR

CODE
7441 .65 A- 74LS151 1.10
II 9312 .70 4073 .16
7445 .60 741.$153 1.10
4075 .16
PHOTOGRAPHY, STEREO REVIEW, POPULAR
7447 .75 SCHOTTKY 7415157 1.10
ll 1518 .85
7450 .11 74501 .25 7415161 1.25 * ELECTRONICS, BOATING, FLYING,
CAR &
7451 .14 * 74502 .25 7415163 1.50
4528 .75

7473 .28 74537 .40 7415164 1.50

LINEARS
DRIVER, CYCLE, SKIING. Send for YOUR free
7474 .28 74538 .60 7415174 1.10 * 0M882W30 1.75
7475 -40 74065 2.00 7415175 1.50 NE538T 2.75 catalog today. Consumer Service Div., 595
7400 .40 * 74$113 .80 7415193 1.50 NE555V .43
* Dept. CL, N.Y., NY 10012.
on Broadway,
7483 .60 745134 1.50 74LS221 1.25 NE556A .90
7486 .28 74S139 1.50 74LS251 1.50 1458V 75
7490 .45 745140 .50 74L5253 1.50 1458V .52
7493 .50 74S151 2.00 7415257 1.50 566V 1.25
7495 .49 745153 2.50 74LS256 1.50 1.35 HYPNOTISM
74107 .29 70.$172 4.50 rv
540L 2.00

Ortler Mr,mum S10 00 Add 21 00 shipping and hand ng charge per order California residents add 6 °° sales
tax All orders shipped Fir Class wallon 24 hours
1

Order the Ismous lacis 6 volume Programmed Leaning Course --Microcomput r Design is a Snap" Ior
all SLEEP learning. Hypnotic method. 92% effective. Details
free. ASR Foundation, Box 23429EG, Fort Lauderdale,
599.50 end receive special 510.00 credit on any group of ICs.
Florida 33307.
I Satisfaction 100% guaranteed. C.O.D. Orders: Phone (day or night) 408/354-1446
mail FREE Hypnotism. Self-Hypnosis. Sleep Learning Catalog!
Drawer H400, Ruidoso, New Mexico 88345.

ELTRON SunnyvaleBCA 94087 AMAZING self- hypnosis record releases fantastic mental
LFree catalog -Just send us your name and address

CIRCLE NO. 16 ON FREE INFORMATION CARD

J power. Instant results! Free trial. Write: Forum (AA7), 333
North Michigan, Chicago 60601.

: ßuó ¿K EPROM . $24.95

2522 STATIC SHIFT REG S 1.95
2513CHARACTER GEN S 9.95 4 /2" x61/2" SINGLE SIDED EPDXY
1 .22UF 35V 51$1.00 6.8UF 35V 3/S1.00 PRV 2A 6A
2518.11E X 32 BIT SR S 3.50 BOARD 1/16" thick. unrtcherl 47UF 35V 5/51.00 22UF 35V S .40 200 75 1.25
5.60 Pa , 5/52.60 .68UF 35V 5/51.00 30UF 6V S .40 400 .95 1.50
210211 1024 BT RAM $ 1.39
,2804K DYNAMIC RAM 1UF 35V 5/51.00 33111- 35V $ 40
S 6.95 7 WATT LD -65 LASER DIODE IR $ &95 2.20UF 2055/51.00 47UF 20V S .35
600 1.20 1.75
MM5202A UV PROM $ 6.95 SANKEN AUDIO POWER AMPS
MM5203 UV PROM $ 6.95 2N 3820 P FET $ .45 3.3UF 35V 4/51.00
1702A UV PROM
5204 -4K PROM
$
$10.95
5.95 2N 5457 N FET
2N2646. .
$
$ .45
.45 4.7UF 15V 5/$1.00
M7001 ALARM CLOCK CHIP SO 7O.
Si 1010 G 10 WATTS.
Si1020G20 WATTS
S'7 95
.... S

AY.5 -1013 UA_RT ........ ..... $ 6.95 ER 900 TRIGGER DIODES 4/ $1.00 d24. EIGHT
Si1050 G 50 WATTS
CCD 110 LINEAR 256 XI BIT SELF
2N 6028 PROG. UJT NATIONAL MOS DEVICES
MINIATURE MULTI -TURN TRIM POTS
100, 500 21Ç5K,10K,25K, 50K,100K,200K
8 PIN DIP SOCKETS
14 PIN DIP SOCKETS
..... $
5.25
.24 Á1M1402 - 1.75 MM5057-- 2.25
CONDUCTOR
SPECTRA
FLAT CABLE
SCANNING CHARGED COUPLED
DEVICE $65.00
Meg. $.75 each 3/$2.00 MM1403 - 1.75 MM5058- 2.75
16 PIN DIP SOCKETS $ 28 0'/51.50
1

MM1404- 1.'5 MM5060- 2.75 CCD 201 100 x 100 CHARGE

MULTI -TURN 1 R1M POTS Similar to Bourn; 18 PINDIPSOCKETS $ .30 MM5013- MM5061- 2.50 100'/513.50 S99.00
2.5C COUPLED DEVICE
3010 style 3/16 "x5/8 "x1 .1 /4 50. 100, 24 PIN DIP SOCKETS S 40 MM5016- 2.50 MM5555- 4.75 a30 WIRE
K, 10K, 50K ohms $1.50 ea.. .3/04.00 28 PIN DIP SOCKETS .50 WRAP WIRE Send 25t for our catalog featuring
1
S MM5017- 2.70 MM5556- 4.75
LIGHT ACTIVATED SCR's 40 PIN DIP SOCKETS S .60 MM5055- 2.25 MM5210- 1.95 SINGLE Transistors and Rectifiers
TO18,200V 1A. S 1.75 VERIPAX STRAND
PC BOARD MM5056- 2.25 MM5260 1.75 too !91.40
145 Hampshire St., Cambridge, Mas
TRANSISTOR SPECIALS This board is a 1/16" s,nyle sided paper epoxy

2N3585 NPN Si T0-66 .. S .95 board, 4'. "56'." DRILLED and ETCHED TTLI SERIES 74LS 74LS LINEAR
2N3772 NPN Si 10.3 . $ 1-60 which will hold up to 21 single 14 pin ICs 7400- .14 5- .15
744C 74150- .90 SERIES SERIES CIRCUITS
2N456A PNP GE 75 or 8, 16. or LSI DIP ICs w,an busses for .14 7446-- .65 74151- .60
254908 PNP Si TO.3 S
S
1 00 power supply connector. $4.00 . . ... 7401-
7402- .14 7447- .65 74153 .60 74LS00 .23 74LS155 -
-
1.40 LM 308 - .95
286056 NPN S. TO3 7403- .14 7448- .65 74LS02 .23 74LS157 .98 LM 311 - .95

7405-
mlton 1.70 MV 5691 YELLOW-GREEN 74154 .95
D-
... ... 4/$
S
7450- .15 74LSO4 - .28 74LS160 1.50 LM 318 - .35
295086 PNP Si TO-92
..... 1.00 BIPOLAR LED S7 25 7404-
- 29
74155 .70
74LS118 .23 74LS161-145 LM319 - .95
2514898 PNP TO-66 5 .60 FP 100 PHOTO TRANS S .50 . 8
1.211088 .

.29
74157- .58 74LS10 - .23 74LS162 - 1.50 LM 324
2N404 PNP GE TO5 5/S 1.00 RED. YELLOW, GREEN or AMBER 7406- 5 74737472- 74161 .85 74LS11 - .23 74LS163 - 1.50 LM 339 - .10
2N3919 NPN Si TO-3 RF . . $ 1.50 LARGE LED's 6/51.00 7407- .25 7474- .29 74163 .80 74LS20 .23 74L5168 2.15 LM 370 - 1.15
5/PSA 13 NPN S. TO.92 3/5 1.00 1L-5 IMCT -2) $ .75 7408- .18 7475- .45 74164- .95 74LS21 -23 74LS169 - 2.15 LM 377 - 2.50
2143767 NPN 5, 10 -66 S .70 MOLEX PINS 100/51.00 7409- .17 7476- .30 74165- .95 74L522 .23 74L5173 2.45 LM 380 - .95
2N2222 NPN S, TO18 . ... 5/5 1.00
WATT ZENERS 3.9, 4.7, 5.3, 8.2,
1000/58.00 7410- .14
7483-
.35 74173- 1.20 74L527
74LS30
-
-
.27
-23
74LS174
74LS175
-

-.
1.20
1.22
LM
LM 362
381 - 1.25
- 1.25
2N3055 NPN Si TO - S -80 10 7411- .20 _62 7417417475- 95
74L5190 1.75 537 - 2.50
2N3904 NPN Si 1092 .. .. 5/5 1.00 12,15,18,22,100,150 or 200V sa. . $ .60 7412- .20 .- 87 - .
741.532
74L537
- .33
.37 74LS 191- 1.75
LM
LM 553 - 2.50
7486- .30
2N3906 PNP Si TO.92
2515296 NPN Si TO-220
2516109 PNP Si TO220
5/S
S
$
1.00
.50
.55
1 WATT ZENERS 4.7, 5.6,10, 12, 15
18or22V
MC6860 MODEM CHIP
... ......... ea. $
$9.95
.25
7413-
7414-- .63
7416- .25
.39
7489
7490- .42
1.85
74176
74177- .75
74180 .65
.75 74LS33
74LS74
-
-
-37
.49
74LS192
74LS193
- 1.75
- 1.75
74LS195 - 1.25
LM 555
LM 556 - .85
74L590 - .95
2N3638 PNP Si TO -S 5/S 1.00 7417- .25 7491- .58 74181- 1.90 74L542 -. .88 74L5196 - 1.35 560 - 2.00
2N651 7 NPN TO -92 Si .. 3/S 1.00 7420- .14 7492- .43 74190- 1.00 741573 - .43 74LS197 1.35 565 - 1.10
3A 7425- .25 7493- .45 74191- 1.00 45 74L$257 - 1.35 566 - 1.50
CIMOS (DIODE CLAMPED) 1A r 12A 50A 125A
7426- .22 7494- .70 74192- .83
74LS74
74LS76 43 74LS258 -1.38
74C10- .22 4016- .40 4029. 1.10 100 .06 .14 .30 .80 3.70
7495- .65 - .53 703 _
7427- .25 74193- .83 74LS93 .89 BO
74C193 1 -50 4017-1.05 4030 22 200 .07 .20 .35 1.15 4.25 7430- .14 7496- .65 74194- .85 74LS92 85 74LS365 - 68 709 .25
4001- .22 4018-1.00 4033 1.50 400 .09 25_ .50 1 t0 6.50 7432- .25 74107- .28 74195- .52 74LS93 .85 74LS366 .68 710 - .35
4002- .22 4019 25 4035 -1.10 600 .30 1.80 8.50 74L5109 74LS367 - .68 711 .35
.11 .70 7437- .21 74121 - .33 74257 1.25 .50
74L5368 - .68 741 C or V - -31
4006-- 1.20 4020 1.05 4042 78
800 .15 .35 .90 2.30 10.50 7438- .21 74123- .65 74279 .87 74L5112- .43
74LS390 2.20 747 .65
4007- .22 4022 95 4046 -2.25 1000 20 .4 5 1.10 2.' 5 12.50 7440- .14 74125 .40 75324 1.75 74LS113 .43 -

LN11310 - 2.50
4009- .42 4023 4049 40 74LS114- .43
-
.

22 7441- .70 74126 .40 75491 65 1456

4010- .42 4024- 75 4050 40 SILICON SOLAR CELLS 74132 .67 74LS132 1.10 LINEAR .95
7442- .40 75492 .65 74LS138 1.25 CIRCUITS 1458 -- .60
4011- .22 4025- 22 4055 1.50 CA 3046 - .75
4012- 22 4026 1.25 4066 80 /s" diameter 2 741_5139 1.30
- .95
741_5145 1-15 CA 3047
4013- .40 4027 40 4071- .27 .4V at 500 ma. $4.00 /.2V at ZOO mils $2.00 MINIATURE DIP SWITCHES LM 101 -.75 3900 - .49
CTS -2064 Four SPST swaches 74LS151 .98 LM 301/748 -.31 - 3.90
4015 95 4028 BE 4076 1.05 ULA RS in one mm.d.p package, . . 51.75 74LS153 - .93 LM 307 - .30
3038
309K S .95 340K- 5,12,15
IN 4148115514/ 15/5100 CTS -2068 Eight SPST switches in a 16
723 S .50 or 24V 51 25
340T -5, 6, 8. 12
pin DIP package- $1.95 TRIACS SCR'S
MCA 81 OPTICAL LIMIT SWITCH 51.50 LM 376 . $ .60
320K -5 or 15V $1.40 15.18 or 245/51.10 5 -8V SPST Miniature reed, relay., normally PRV lA 10A 25A 1.5A 6A 35A
LED READOUTS 320T- 5,12,15 78 MG $1.35 open, 330 091-1.1coil resntance. 5.75, 3/52.00 100 .40 .70 1.30 .40 .50 1.20
`:D 359 C.C..4" $ .55 HP 7740-.3" C.C. $1.25 or 24V .. $1.25 79 MG 51.35
200 .70 1.10 1.75 .60 .70 60
-ID 70 C.0 .4" .60 MAN-7-.3" C.A.
$ $ .95 ALCU MINIATURE TOGGLE SWITCHES -
1
l

O ND 503 C.C. .5"

RS232 DB 25P male $3.25 MTA 106 SPDT $1 20 400 1.10 1.60 - 2.6Q 1.00 1.20 2.20
05 NS 33-3 dig array
$1 $ .75
DB 255 femele
CONNECTORS 53.95 MTA 206 DPDT $1 70 600 1.70 2.30 3.60 1.50 3.00
FND 510 C .5" 01.05 DL 747 C.A..6"
. 51.95 I

Terms: FOB Cambridge, Mass. SOLID NATE SALES WE SHIP OVER 95%
OF OUR ORDERS THE
Send Check or Money Order.
Include Postage Minimum
Order $5.00, COD'S $20.00 45 P.O.
SOMERVILLEBOX ,
74A
MASS. 02143 TEL. (617) 547-4005
DAY WE RECEIVE THEM

CIRCLE NO 47 ON FREE INFORMATION CARD

106 POPULAR ELECTRONICS
 POLY PAK'S IS THE "BARREL KIT KING" OF THE WORLD!

\,'`1 SURE-
V

` \''\ '
-

JJ BARREL KITS

4 ..? FIRE
/
THE
::
, AND CHOOSE
TH
k kikbilokk 44
,
,4 '= Avg, Ship,
1ree/
1
1
WAY TO FIGHT
4 IVi Wt. 6 -ozs. \
Free.
Test 'em yourself 'n save! Includes 100% material, too! INFLATION! Each kit carries a money -back guarantee. i, No..

rL':.^K
BARREL KIT :239 BARREL KIT #230 BARREL KIT #225 PI BARREL KIT #221,, MIXED READOUTS BARREL KIT #20 BARREL KIT :203 us
\'
-

SHIELDED CABLE (/
/$
HALF INCH CALCULATOR oROD0
50-ft $1.98 READOUTS
SOUND TRIGGERS
for
IC SOCKETS
8 for 5 for
KIT JMINI BLOCK KEYBOARDS ens"
7E 3629
15 for $1.9 f
,1
3
$1.98
s'1r^1t\
a. $1.98
Barrels of untested 17 '
hobby ",
If l J
1.9$ #219 1
(CAPACITORS
S0 for $1.98
Unbelievable! Worth $50.
10 for $1.9 y 66
It's true! 20 -key, 4 tune-
For mikes, at eon; 1-cond. From factory to you. In. !land clap" eeifiiitises cry+- Mfr unloads! Friar 1 -Din, 3 ", .5 ", 7 -sage, Like FWD- High lion keyboards at ridicu

/
cal mike amplifier, triggers four precision eubmiai
Plue shield, 22 ga, vi 21 chide. Fairchild FND -600 18 -pin. Solder tail, 367, 500, 603, MAN -3'a. caps for all application
't. loos give -away. Wt. 12 O.
jacket. Wt. 1 lb, 7E3377 & 607A SCR. Cat, Ne. 7E3625 lo- profileNe, 7E582í ut a burl N. 7E 3619
// 3 ors. Cat, 7E 1528 Cat. No. 7E 3524

i!;
BARREL KIT #210 J/ BARREL KIT #201 ARREL KIT #2ÓÓ BARREL KIT #194 , ARREL KIT #191 BARREL KIT #100
O 6V INDICATORS J/.
w /leads RADOT DARTO
!rN8 P
D
15 for $1.98 MDULES
5 for
50
800for $1.98.
Test lamp manufacturer for .p.e. wink.
-green eles dumps inventory! AC. DC,
Worth $1.98with calculator Motorola dumps 1,000,000 x !'"und, a0prox- ''e. brrrermed,
Preformed,
red
dumped into
Use for nice Noes, 3550 4-9 pin, all E352 Wt. I Its. Cad Like Era26 driver 7E beneath epoxy TO-220 in ^ e. .tat values. í.7E140. 100%
a, etr.Gt. No. 7E]á50 Cat No. 7E 3527 Wt. No. 7E J328 hobby Cat. N.
No. 7E 3515 N. 7[3333 marked. GL No. 7[3445
k PNPs. Cat: Ne. Cat. Ne.
Cab 7E !401
BARREL KIT #167 BARREL KIT #105 BARREL KIT "184 BARREL KIT #102 BARREL KIT #163 BARREL KIT #161 BARREL KIT #160
AUDIO IC'S PC BOARDS %-WATT METAL FILM JUMBO RED LEDS MINI TRIM POTS POP' PLASTIC
30 for Sprague,
a. 400 parts
row so-
I I
150 for Y 15 for $1.98 30 for1.... TRANSISTORS
25 for w:$1.98 10 for
V. REGULATORS

some $1.9$obby
National 2 to 100 !ó material, user
4
377,
etc r LM -380, LM. 50 transistors, 60
2277, etc. DIPa, Darts: transformers, 200 $1.9$ ellation from
u can-
d
$1.9$ 2 N3 904 ' e t h
'''''IN
^ dumps, 3V 10For Asst, values 100 to 1 m g
mils. 2ot. of 10090 mate- Na 7E3330
some with heat sinks.
\ r.Cat. No. 7[3388
stars, diodes, etc. ]009.
I
metal film resta - 100's of projects, red lens. What buy. Single turn. rial. TO -92. Preformed.
TO-92. KC TO-3 V,R,'e bar -
atedth No. 7[3397 Lora. Long leads. 7E3413 Cat, No. 7E 3389 14 W. Wt. 0 es. 7E3345 Cat, Ne. 7E3343 1 oz, reled. Bot by the pound,
BARREL KIT #159 BARREL KIT #156 BARREL KIT #155 BARREL KIT #154,. BARREL KIT #145 BARREL KIT #136
MODULAR SWITCHES MAGNIFIED MAN-Vs KIT `144
MOLDED CAPACITORS CLOCK CHIPS MINI RCA PHONO PLUGS PANEL SWITCHES
25 for 20 for 20 for
1

$1.98
yf
$1.98 p
_ TRANSFORMER for
$1.98
' 1

40 for $1.98 30 for,1 A- '

Cenlralab r?/'r/ex. readout,

i-
with b disco n 7E331í h bb>
chi a riment
15 $1.90 = I I
1
for

í,000,60o RCA D noon plu es

for this one. You hi -A -ers Dih you hear of OAK! An
$1.98 °
w [thee. TV- makers
s. Coat o.
- magnifier.
31. Brand timeC live. 703% mate-
Asst.
Factor y distort- green, r Itnges, red, °f clock chip, alarm, ales-
blue elastic dite, beepers, who knows, stage and audio.
s, in t e - $1.98 know wutn they are . °cher eupt maker barrelled
eve. Cat. No. 7E 3150 rial. Cat. No. 7[3325 oz. cas seal leads, l lb. :tit' mixed. Cao MO,. 7[3308 +I. tVt. 2 í6s. 7[3294
1r"
10090 material. 7E 3293 all types rotaries.
.lides,fele 3288
BARREL KIT #135 BARREL KIT #12 BARREL KIT #127 BARREL KIT #126 BARREL KIT #116 BARREL KIT #117 2 BARREL KIT #115
MICRO MINI LAMPS MINI DIP ICS
AXIAL ELECTROS //
UPRIGHT ELECTROS MINI SCRS OPTICAL FI ERS osa. MOLEX -e-
20 for 400for $1.98 /7n 40 for 40 for 50 for $ 1.98 2O- L
97[329. SOCKETS í0o
good
$1.98 l p,
Large mfg. dumped 100.
into barrels. Includes
lbs
,
$1.95 $1.98 UNBELIEVABLE! TO -92 200M1L $ÿ;98 200 for c,t,pp ngiln
Imagine! Micro
-,
t+ x 741s, LM- 380 -8, 703, 567,
with .ire lends. :t In 555. 5If,
Asst
but who knows? voltigea. Cal.capacities and lmf to :100mí i mixture
Plastie SCRS barrels ..
e from factory, Includes
No. 7[3227 of voltages. 10090 marked pr voltiges up thru 200
Fiber optics factory bank_
cup icy purchase! High quai-
icy, nitoil- commonly used
$198
Calculator, :raker dump'
7[3144 I l o

5 V11C, 4n m,l.. 7E3259 W. In. 7E3249 hobby 1 n good, 7E3226 pro 7E3136 site 20-mil). CLEAR. Eut a r. h.. of 'em.
1\'e

BARREL KIT :112 BARREL KIT #109

,
BARREL KIT «100 BARREL KIT "104 BARREL KIT #101 BARREL KIT #99 BARREL KIT #93
MICRO MINI LEDS TERMINAL STRIPS TO -5 PLASTIC ¡SLIDE VOLUME RESISTOR SPECIAL PHOTO ELECTRIC HALF WATTERS
40 for
1 is

100 for $1.98 TRANSISTORS

200 for 200 for $1.98
$1.98
All the tiny Jaca,
Hobby Wide ut terminal stripp
axial. p- connectors,. from 1 contact
Cat.No. 7E 3101

right of Monsanto, Litravix, up. Strip manufacturera Includes PNP, NP V, 2N-

40 for $1.98
CONTROLS
10
$1.98
forte' ,,,j $1.98
Include.: _/ , Vs. Va.
1, 2-
CELLS
10 for $1.98
À st. GE types, CDS types,
Mixed by factory. Big job
Resistor factory' tried to
tm 1u, by mixing 100
color -coded resistors in
:
variety of colore. Yield barrel dump is your gain, .36:18, 2N3641, 2N5000 w teena, carbon. 8 oz, forus to separate. 100% barrel. But value is there,
50% or better, 7E 3139 Wt. 1 1b. COLN., 7E 3336 ,,eries, etc. Untested. Cat.No. 7E1057 1007 good. 7E3054 good. Cat.NO. 7E1032 4 oz, 7E3046 Untested

BARREL #91
SILVER
100 for $1.98
MICAS LITRONICS
READOUTS
BARREL KIT #88
100 for
LED
\
BARREL KIT #67 BARREL KIT #86
NATIONAL IC BONANZAHOBBY LEDS
40 for ',/] 15 340T$i `
M
BARREL KIT #63

M-
= ARREL KIT #8I BARREL KIT #76
SUBMINI RESISTORS I -WATT ZENERS
200 for 100 for $1.98
10 for $1.98` >_ Type,
$1.98 $1.98 Untested VOLT REG Factory rime as offer,
case,
as variety Hobby ,agio., it - ,111111, '7111!! taries 74, 32, singles,
R tri- Factory rrjeoted t e mr PC. priant type, cover end. N. -nee. to Her.
Axial, ared regl,tet,, clock proms etc.
,
I

values.
paf plc., .:t'. 1, 0. O, (tot & , HD51s, to 0.m of leeds,My roide a ' vent!. Arbt valuer. 10, 12, its.
gl under
Cat.No. 7[3016 Iii of !.a m av:l; k .Nd. chips, lionne,, rte, factory,
from ont tory. II mixed; b, w
6. t2, 15, tM. 24 volts Catie in us 7 e barrel. glass. Double plug.

I
h.,ec fr.o'No. 7[2881 Cat.No. 7[2980L'ntesteQi have font 7E 2859 Power tab Cat. 7E 2635 7[27461
Cat.No good GLNo.17[3741 Untested.
BARREL KIT «73 BARREL KIT #71 BARREL KIT tel
DiAleoIII I/''e/
BARREL KIT #06 KIT #65
TRANSISTOR CAPACITOR SPECIAL 2 WATTERS POLYSTA CAPS

f
MIXED READOUT
ELFGYROS 100 pest 100 for 10 for $1.98 ®100 for
50 for $1.98 $1.98 $1.98 100%
g od.
Factory
umbers
returns 51.98 :-Asa
MAN -4's, MAN- Finest
h

dort wish to separate micas,csm Ideda, plastics, Suppliera throw e in the 7's. MAN -3's, 11 barrels d b1e wecapa made. gam

BASIC KITS'
We
wide east voltages & values discs, etc. Nifty barrel, It's bought 10 barrel
, li'I gold mine. time to separate. Hobby from factory, mixed values
up to 300 mf. Cat. 7[2747 100%good Cat.No 7[2736 All marked, Cat.No. 7E273 ál Cat.No. 7E 2733
Uneestea, all anon. Cat.No, 7E 2729

all components except

line cord.
4 DIGIT
former, case

\
Designed for the economy-minded. Includes:&

`in \'I.I / I -r III

_
A$ A
i
BARREL KIT #56
SLIDE SWITCHES
30 for sixes,
$1.98 '100 for
aDat.ape: Q
m'OTêap:;1QSaea Teem
anus shop pakefor 100's of
BARREL KIT #56
POWERS! POAWERS!.

$1.98 eat 7E 3720

Large distributor cleaned
BARREL KIT #54
,8 DIGIT READOUTS
10 for
Bargain f a lifetime! All
got I barrel
$1.98
í4114
= BARREL KIT #40
" 20 for
PNP HIGH -POWER
TRANSISTORS

p Hobby
-the $1.9$germanium
14, .et..
BARREL KIT #39
2N3055 HOBBY
TRANSISTORS
15 for
$ 1.98
s .,

-_
-

FLOU RESCENT - ,O switching p2728í ree8 Bartol7 oaf power glotte digit" types. Multi- Popular
resistors
tors 3 to 7 watts. TO -3 Fallouts of th f- mou
7[2726100 %good
Cat.No. plotted. Cat No. 7E2722
essa 7E 2618100% good -NJ 055. 7E2617100%
$9.95 R ó
'.e8
o. BARREL KIT #37
1 AMP BULLETT"
BARREL KIT #36 BARREL KIT BARRELKIT #31 BARREL KIT "]0
«

..57" Bright Blue Digits RECTIFIERS Untested

GERMANIUM DIODES NEON LAMPS M
RESISTORS
IC -yst¡E(1+- PREFORMED
lock made! lises segment GF. tube 3O fOr RESISTORS
The brightest
readouts. Includes famous MM5336 clock chin and
7
100í0r$1.98 200 for7E2614 1n1e9ed
$1.98 $1.98 100% Baas. -100 for $1 98 200 for 1.98
components! Easy and fun to build, ramona sstyle.
Ye, .sala. H- lam.. NE -2's. All prime,
M.ae mq.uy br ctoa her`el, of :s
per[ec[mfor the ne hobbyist! 12 hour display, 624 the finest stator made, re.,g

'\
ages, silicon, axial includes Cat
I

N1o.
but factory made millions Mostly pc use' ;: t r
Options clade cl
hour cycle), AM -PM indicator. timer, f voltigea to Famou, maker. popular and harrel'ed 'em, Your t/2 watt 19t W 100 for veal tern.
dia timer, 60 minute sleep
snooze PC d all types
1KV.Cat.NO. 7E 2815 +lem. Never grows old. Cat.No 7E 2613
ya9a fol. & aewharrel of
100:
No, 7E 2608100.6 go
, t

included Easy to breadboard, wits

instruc- lues. Cet. No. 7E2609
board our 92CÚ3412.
t

Dons. Requires 12 V transformer, nee BARREL KIT #27 KIT #26'PLASTIC BARREL KIT #25 BARREL KIT #20 BARREL KIT #15'
Cat. No. 7E3791 Digit Fluorescent Basle Kit 59.95 PREFORMED DISCS METAL CAN LONG LEAD DISCS DIPPED MYLARS $'re
2.91 TRANSISTORSR5
Cat, Ne. 7E3792 Components
g as our
Same famous design
for Alarm Option
[j¡M
150 for
$1.98 s
íór
$1.98 HobE
TRANSISTORS
100 for $1.98 100 for 60 for $1.98
KRONOS BEEPIN' Hi -Fi ft's hell ventory $ Uataetéd. Includes TO-6, TO -1, TO $1.98tale'.
-auction Prime,
Finest capacitors made.
shiny finish. Imagine fact_
but he dumped 'ern bar- Type TO -92 (TO -1.8), all 18, etc., assorted 2N
-6''' `
m n um_
facturers, variety of ,mty. Long leads' v dumping 'em in barrel..
TIME MACHINES.
/
1 values for n,

. ¡f BARREL lues tool 7E 2809 2N Cat.No7E 2604 Cat.No í7E 259810090 goof
pq Mixed #':s. Cat.N. DE 2603 Untested. Cat.NoJ7E 2597 100 g. good

6 DIGIT BEEPERALARM LINEAR

NIT #17
74
BARREL KIT #13
MOSFET KIT #1
BARREL KIT #11
POWER TAB
BARREL KIT #10
ROMS- REGISTERS
PRECISION RESISTORS TRANSISTORS
° $12.95build!,35" LED RED DIGITS el
100 for TRANSISTORS 75 for
time in hours, for ap1.98 200 for 40 for $1.98
Easy and fun to n ,wait display W. IMO Hubby Untested `P3`$
notes and seconds. 12 hour format, 24 and hour cycle.
a mini-
Marked an unmarked in (All 4 leaders 70,18 case $1.98 NPN, plastic
,
70220 type.
Untested Hobby

}.
7'm pute snooze. Uses famous MM5375AB ferial numbers of raw far -' includes 11íy transistor. Marked and unmarked 1/4. 20 to 40 Din device.,
murn of components. Controls for slow and fast set, cry stork, Cat.No 7E 2431: tUO- Cat.No.7E 2429 /z.
= 2 w'atta.a 7E 74 28 Assorted 2N numbers. naked. :sternal [.
and tees t to zee Includes all necessary components Ne. ME 2423 Untested. numbers,, to Cat.No. 7E 2424
Requires 12V
cept for case line ord, PC board. PC boards BARREL KIT «a BARREL KIT #7 BARREL KIT #5 'BARREL KIT 74 BARREL KIT 7 3 r19-
Trarinformer, nee our Catalog #92CU3412. ozs. SUBMINIATURE
9 VOLUME SCRS, TRIALS, "4000" RECTIFIERS /914 ODES
vaìlable write or call for information. Wt. 8 basic
100 for
1
kit CONTROL QUADRACS
Cat Ne, 7E3793 8 Digit LED alarm clock IF TRANSFORMERS SWITCHING DIODES
COMPLETE. KIT: includes case, transformer 75 for $1.98 $1.988
fOr
Set 40 for / $1.98 Untested. 100 for $1.9ií
, 1009 $i98. '0 or'''''
°pd 1Ntnon Mar Imagine
and line cord, Cat. No. 7E3505
i -
Amarina, includes 455kes Raw factory rinds 25, s.í00, 2nÓ, at"teses
who known?
a
Cat.Nantenn422100 %(good _
Singles, duale, variety of
values, styles, big ones stock! All the 10 amp types. 400. 600. 800 and 1000
dindes
Cat.No. 7E2415 Untested.
5 tF 9
4 DIGITDIGIT $LED ,, mall ones. Cat.No.7E 2421 Cat. rio í7E 2418 Untested. vol ter9, 7[2417
Some o 6
AI.ARM CLOCK BASIC, x-
I° 4 - BARREL KIT #2
LINEAR OP AMPS,
BARREL KIT #1
SN7400 DIP IC'S.
Terms: Add pootaxe Rated' net
Phone : Wakefield, Mass. (617) 245 -3829
30 SALE I
rj---
apt with .6" digits, die 75 for El Sen for FREE
plays hours d
. tea,
Winking edmao Cotta sec-
onde. Wt. 8 ozs. Cat Ne. 7[3794
; .II
1

'J
, Dips
Um
coated $í.9s Marked 14 and/or with 16
75 for $1.98 Retail: 16-18 Del Carmine St.. Wakefield,
POLY PA K S SUMMER CATALOG
COMPLETE KIT: includes case, transformer
May include
riuden
709's, 741'x, pin dips, may i elude gates,
703'x, 560 series. 555 In- resisters. ip ñopn,
7E2416 hobby era. 7E2415 !.ratent Hobby
t f C.O.D.'B MAY
and line cord. Cat. No. 7E350'7 °,$19.95 P.O. BOX 942E LYNNFIELD5 MA. 01940
oly Paks
JULY 1977
Inc!; Wakefield, Mass., U.S.A. 1977
CIRCLE NO. 39 ON FREE INFORMATION CARD
MINIMUM ORDER - $6.00
BE PHONED

109
 IniM 7400N TTL Tiff,
S47/004 .16 S474594 .25
Tmeband
- Watches
- 6yfn/RObm
- WIRE WRAP CENTER
HOBBY -WRAP TOOL -BW -630
S474014 .16 S474604 .22 S4741544 1.00
5474024 21 S474704 .45 S4741554 .99 Men's & Ladies Battery Operated (Size C)
S474034 .16 S4.74724 39 S4741564 .99 Weighs ONLY 11 Ounces
S474044 .18 04747354 37 S4741574 .99 Solid State Wraps 30 AWG Wire onto
54740514 .24 5474744 32 5474160N 125
54740611 .20 5474751 50 5474161N 19 Displays hour, minute, 70441 White w /strap 529.95 Standard DIP Sockets (.025 inch)
S474074 .29 5474764 .32 99741634 .99
5.00 T201 81008 Bracelet 519.95 second, month & day TC440 Yellow w /strap $34.95 Complete wdh built -in bit and sleeve
94740814 54747954 54741644 1.10
.25
$34.95
-
5474094 .25 S474804 50 LED LCD
S4741654 1.10
5474104 .18 0474824 98 S4741664 1.25 Snap -out battery batteries not pc ude4
04741116 .30 S474834 .70 S4741674 550
5474124 .33 59748514 89 S4741704 2.10
replacement WIRE -WRAP KIT WK -2 -W
S474134 A5 5474864 .39 S4741724 8.96
S474144 .70 S474884 150 1.50
Free set of replacement WRAP STRIP UNWRAP
S4741734
S474164 35 S4748914 249 S4741744 1.25 batteries Tool for 30 AWG Wire
S474174 .35 S474904 .45 S4741754 .99
S474204
547421N
S474224
.21

49
33
S474914
S474924
S474934
.75
49
49
S4741764
S4741774
S4741804
.90
.90
.99
Choose LED or LCD
styles
Roll of 50 Ft. White or Blue 30 AWG Wire
50 pos. each ", 2 ", 3" & 4" lengths
pre- stripped wire.
1 -
04742354 37 5474944 .79 54741814 2.49 1237 While w /bracelet 529.95
One year factory
$11.95
,/
5474254 29 55474954 .79 5147418214 15 T311 While wlnrap 534.95
3236 Yellow et/bracelet $34.95
S474264 29 S474964 .9 54741848 1.95 T310 Yellow w /strap $39.95
S4712754 17 04749754 4.00 547418515 2.20
LEO warranty

e
S474294 .42 547410014 1.00 5517418614 15.00
WIRE WRAP TOOL WSU -30

-
51474304 16 5517410714 .39 04741874 6.00
5474324
SN7437N
.31
.27
5447412154
S4741224
.39
.39
04741884
54741901S
3,95
1.19
CHANNEL( F Freeze Action Speed Option
Automatic time and storekeeping
WRAP STRIP UNWRAP -55.95

S474384 .27 04741234 .50 S4741914 1.25 WIRE WRAP WIRE 30 AWG
54743954 54741258 w
tj1 Battery -tree AC operation
-
25 .60 54741928
047440111 15 5547412614 .60 S4741934
.89
.9 Dual controls with 8 -way action
2511. min. $1 25 50f. $1.95 100 ft. $2.95 1000tt..$15.00
547441N
S14744214
54744311
.9
.59
75
954741324
547413681
54741414
1.09
.95
1.15
9147419451
5474195N
54741969
125

1.25
.75 $159 95 Built-in Pro Hockey and Tennis games
Easy hook -up on any B/W or Color TV
SPECIFY COLOR White - Yellow - Red - Green - Blue - Black

Plastic Push Button Switch

-
Factory warranty

-
55474444 .75 547414214 4.90 54741979 .75
5474454 .75 5117414314 4.50 54741989 1.75 18 AWG Solid Wire - 5" Long
S4744614
S474474
81
69
514741449
547414511
4.50
1,15
S4711994
5167420061
1.75
59
Channel F additional cartridges ea. $19.95 .50 (wide) X .60 (high) Ye-27 Thread
55474484 79 547414744 215 S11742794 .90
#8112 - Desert Fox /Shooting Gallery #8113 - Blackjack (1 or 2 players) 8 AMP W 14 Vo6- 1 AMP W .10 Volt
5474504 .26 54741484 200 S4742514 1.79 #8114 - Spitfire (1 or 2 players) 4,8115 - Space War 1-9 10 -Up
5474514 S4741504 1.00
.27
54741518 79
547428411 6.00 #8111 - Tic -Tac- Toe /Shooting Gallery/Doodle/Ouadra-Doodle J -188 -1 Push On -Push Off .59 .49
S474534 .27 S4742854 6.00
S474544 .20 54741539 19 sN743678 .75 J- 188 -2 Normally Open .59 .49
MANY OTHERS AVAILABLE ON REQUEST 125" a. .16S' da.
J -188 -3 Normally Closed .59 .49
X0209 Red 1010 %C111 Rea 10/51
20% Discount for 100 Combined 7400's Green 451
00209 Green 451 %0111

DISCRETE LEDS Yellow 411 DIP SWITCHES

C04o00
C0191
25
25
CMOS 740044
7401051
75
65
00 Orange 411
X0111 Orange 451
SPST Slide Action
C04002 25 004035 1 85 740204 .200' 44 .185" eia. .200' dla. .95" aia,
X022 Red 10/$1 X0526 Rea 5/51 X0556 Red 10151 MV50 Red - 551 #206 -4 18 pin dip) 4 switch und $1.75 ea.
C04006 2 -50 C04040 2.45 740304 65
004007 25 C04042 1.90 74C42N 2.15 X022 Green 4/51 X0526 Green 4/51 %0556 Green 4/51
#206 -7 (14 pin dip) 7 switch unit $1.95 M,
4/$1 INFRARED LEO

-
00409 004044 1.50 1.50 X022 Yellow 4/51 90526 Yellow 4/$1 X0556 Yellow
59 74C73N
431 4. x V. "x1 /16' - #206 -8 (16 pin dip) 8 switch and $2.25 ea.
4/91 00556 Orange

-
X0526 Orange

-
C04(110 59 004046 2.51 74074 1 15 X022 Orange 4 /$1
Flat 5/91.00
004047 SSL-25 RT 41$1 10576 Clear 4'51 X0556 Dear 711
C04011 .25 2 75 7409054 3.00
TV GAME CHIP SET $18.50
C04012
C04013
004016
25
.47
56
004049
004050
004051 2
79
79
95
74954
7401074
740151
2.00
1.25
290
SPECIAL X0556 Red 100/58.00 1000/560.00 SPECIAL
51338
Includes AY- 3- 8500 -1 chip and 2.010 mhz crystal -
52707
DISPLAY LEDS SIO if purchased separately would cost $21.90.

- -
004017 1 35 004053 2 95 740154 4.00
004019 55 004060 3 25 740157 2 15
I75 TYPE 064Á4/7Y HT
C04020 149 004066 740160 325 TYPE POLARITY H T
ZENERS DIODES RECTIFIERS
C04022 1.25 004069 45 740161 3.25 MAN i Common Anode 270 952 MAN 3540 Common Camodo'orange 300 175
TYPE VOLTS W PRICE TYPE VOLTS W PRICE
1001 Matrix 300 4 95 MAN 4710 Common Anode -Red 400 95
MAN 2
1

C04023 25 004071 45 740163 3.00 5 x 4/100

004024 50 004081 45 740164 325 MAN 3 Common Cathode 125 311.00 01701 Common Anode -red - 300 9 14746 3.3 400mm
4001
44005
44006
600 PIO AMP 1 C

99 14751A 5.1 4/1.00 800 PIV 1 MAP

MAN 4 Common Cathode 187 1 95 01704 Common Cathode 300
001025 25 004511 2.50 740173 2.60 91752 5.6 4130m 4/1.00 f44007 1000 PN AMP 1 0'.
MAN Common Anode 300 125 0E707 Common anode 300 99
C04027 69 004518 2.50 740193 275 7
14753 62 400m 4/1.00 43600 50 20011 6100
Common Arwde.gr00 300 95 MAN 4740 Common An000-Fled 400 99
004028 I.65 MC14566 3.00 740195 2-75 MAN 7G 1
154754 6.8 400m 4/1.00 44148 75 1011 15/1.00
004029 2.90 740004 39 MC4044 4,50 MON 7Y Common Anode -ye aw 300 1 95 01741 Common Anode 600 I 50
14959 12 400m 8/1.00 44154 35 10m 12'1.00
CD4030 65 74CO2N 55 MC14016 56 MAN 52 Common Anode-gren 300 .99 DL 747 Common Anode 600 2 25
189656 15 400m 4/1.00 44305 75 25m 20.100
MAN 64 Common 400de.1M 400 99 01 750 Common Cathode 500 2 49
L903MIN 190135114 1,75 1545232 5.6 50011 28 44734 5.6 ler 28
UA91N 35 LINEAR 11.414144 1.75
MAN 74
Mar,
Common
--
Catnone
.w
300
300
1.50
99
01 338
FN070
Common Cathode
Common Cathode
110
250
50
75
145234
1545235
62
18
500m
500n
28
28
44735 62
1447366.8 lw
10 28
28
LA1301C4
LM302H
35
75
78945175
1.1.5
LM1458C
5814969
.65
300 9 FN0503 Common Cathode 500 1 00
145236 7,5 50001 28 44738 8.2 lw 28
LM370N 95
500 00
300 75 F40507 Common Anode
LM304H 19 1543734 3.25 LM1556V 1.85
1 1
1N456 25 40th 6 /1.00 44742 12 1w 28

L41305H LM377N 4.00 LM2111N 1.95 1N458 150 7m 6/100 44744 15 ler 28

1.9 LM2901N 2.95

HP 5082 -73 Multi -Digit Series 144851 19 1011 6 /1.00 N1183 50 PW 35 AMP 160
1M307CN
100
35
35 1438054
FROECJI8g'$' ATARI GAME BOARDS Dip Package 144001 50 PIV AMP 12/1.00 41184 100 PIV 35 AMP 70
LM308H LM380CN 1.05 69
80ABDA -8V0"x16" /e" Ht.
1 Common Cathode 1 1

15130804 1.00 LM381N 1.79 1.M39004 .55 144002 100 Phi 1 AMP 121110 541185 150 PIS 35 AMP 1 50
Over 60 each reusable IC's $6.95 ea. 3 to 5 volts @5 mils per segment 114003 200 NJ AMP 12/1.00 81186 200 PN 35 AMP 19
LM309H 1.10 LM39N 1.79 LM3905N 60
MIsc Tramotors, Resistors, ONLY 500 EA.
1

7 segment Monolithic Red Display 4119

1M396 9 NE501K 8,00 1.153909 1.25
Diodes, Caps. Crystals, Switch, etc. AVAILABLE
144004 400 PW 1 AMP 12/1.00 400 PIS 35 AMP 3 00

LM310CN 1.15 NE510A 6,00 LM5556N 1.85 2 Digit 5 79

15431111 90 NE531H 3.00 MC55586 1.00 DELUXE BOARD B _ 111- x 1E" $9.95 ea. 3 Digit 89 SCR AND FW BRIDGE RECTIFIERS
LM31154 .90 NE536T 6.00 LM7525N 90 Seery() each reusable IC's ONLY 500 EA 99 SCR SI 95
4 Digit C360 154 @ 4000
LM318CN 1.50 515401 6.00 164753554 1.25 Moo. Tranlstors. Resistors. AVAILABLE
5 Digit 1.19 03890 35A @ 200V SCR 1.95
LM319N 1.30 14E55014 79 8039 4.95 Diodes. Caps. Crystals. Switches. LEDS. etc

- 242328 1,6A @ 2030 SCR 50

LM320K-5 1.35 NE555V 39 19075450 49
LOW PROFILE /TIN) SOCKETS MDA 99.1 12A @ 500 FW BRIDGE REG 1.95
15432051 1 35 NE560B 5.00 75451CN 39 IC SOLDERTAIL
LM320K-t2 1.35 NE561B 5.00 75452011 39 1 -24 2549 50.100 24 2149 50 -100 MON 993 12A @ 200V FW BRIDGE REG. 1 95

LM320(-15 1.35 NE5628 5.00 7545304 39 8 pin 517 16 24 pm S 38 37 36

45100
1M320T-5 1.75 NE565H 1,25 75454CN 39 14 pin 20 19 18 28 01n 45 44 43 6155 A05 TRANSISTORS 0044249
154250 ;5100
LM320T-5.2 175 NE565N 1.75 16 pin 22 21 20 RPPnnsrleA 36 pin 60 59 58 MP5 POfi 53 00 P143567 351 00 284400 51 00
LM320T-8 1.75 NE566CN 1.25 75492CN 89 18 pin 29 28 27 40 pin 63 62 61 2922190 35,U0 P83568 451 00 2144001 491 CO

1.95 7549404 .89 22 pin 37 36 35 SOLDERTAIL STANDARD )TIN) 282221 4

45100 451 00
LM320T-12 1.75 NE567H 9043569 204402
27422224
1M320T-15 1.75 NE567V 1-50 RCA LINEAR 14 pin $ 27 25 24 28 in S 9 90 81 008100 K1 1b 25444 43100
1.75 11570304 45 CA3013 2.15 283705 551 00 2044409 ',5100
155320T-18 Yr 39 1.26 15
1M320T-24 1.75 LM709H 043023 2.56
16 pin
18 pin
30
35
27
32
25
9 i 40 pm
1

59 45
1

1 30
2x2.
200414
A
203706
2113707
551
551
00
00
255066
815027
SI 00
451 00
LM323K4i 9.95 LM7094 29 CA3035 2-48 24 pin 49 45 42 2029062
203711 851 00 2145085 451 00
1.35 2N2907Á
LM324N 1.9 LM7104 79 C,AT039 203724 5. 65 II 285089 451 00
SOLDERTAIL STANDARD (GOLC)
1

CÁ1046 1.30 842925 5/5I 00

15433914 1.70 1517114 39 203725 51 00 295129
213050 551.00
0434015 1.95 15172351 55 CAí059 3.25 8 pin S 30 27 24 z4 pin 5 70 63 57 203903 551 00 285138
203055 285139 55100
LM723H CA3060 3,25 14 cm 35 32 29 28 Din t 10 00 90 263904 491 00
LM340K-6 1.95 55 1

8253055 5100
LM340K-8 1.95 LM733N 10 CA309 9 16 pn 38 35 - 36 pin I 75 1 40 1 26 18.82955 e, 25
203905
203906
451.00
431 00
205209
255951
551 00
531 00
1M340K-12 1.95 LM739N 19 CA3081 200 18 Pin 52 47 - 40 pin 1 75 1 59 1 45 203392 5ro 00
254013 351I10 069156R 251 00
CA982 200 #3 203398 53' CO
LM340K-15
LA4340K-18
LA1340K-24
1.95
1.95
195
11474108
LM741CN
19741 648
35
.35
39
CA309
CA3086
1,W
as
10
14
pin
pin
$ 45
39
41
38
WIRE WRAP SOCKETS (GOLD) LEVEL
37
37
gm 24 pin
58 mn
S1
1
05
40 1 25
95
1
85
10
204014
2014123
351
1051.00
CO 205432 52 00

1M340T-5 1.75 LM747H 79 08309 3.75 16 pin 43 42 41 36 pin 159 I 45 19 CAPACITOR SOVOLT CBLAMIC CORNER
1M340T-6 1,75 147474 79 CA991 1020 18 'Jun 75 69 1 'S 55 140
MSC CAPACITORS
LM34oT-8 1.75 LM748H 39 GA3102 2.95
1 -9 10 -49 50 -100 1.9 10-49 50-100
LM34oT-12 1.75 15174854 39 CA3123 2.15
LM310T-15
1143407-18
1.75
1.75
LM1303N
LM130411 1.19
90 CA319
0A3140
1,39
1.25
50 PCS. RESISTOR ASSORTMENTS
IC OHM
$1.25 PER ASST.
10 pl
22 pt
.05
05
.05
.54
.04
.04
.03
.03
.03 .019F
.004791
.019F
05
05
44
04
.04
.035
035
.035
LM340T-24 1.75 LM1305N 140 CAi6W 1.75
12 OHM 15 OHM 18 011M 22 ]HM 47 11 .OS

ASST. 1 5 ea. 27 OHM 33 OHM 39 OHM 47 OHM 56 341M 1/4 WATT 5% 50 PCS. 100 pl 45 104 .03 .0229F .06 .05 04
1543504 100 LM1307N 85 004194 595
220 pf 05 .04 .03 .0479F .O6 .05 44
LM3510N .65 1/Á1310N 2.95 R04195 3.25 6E OHM 52 OHM 100 OHM 120 OHM 150 OHM
470 pf 45 04 .035 .191 12 09 .075
ASST. 2 5 ea. 180 OHM 220 OHM 270 OHM 330 OHM 390 OHM 1/4 WATT 5% 50 PCS. 19 VOLT MYLAR
74502
741503 29
74LS00
741574 49
TTL;115;
7410153
3-72
1 55
1.89
JQ ASST. 3 5 ea.
47C OHM
I.2;
560 OHM
1 5K
680 OHM
1.8K
820 OHM
2 2K 2.7K
1K
1/4 WATT 5% 50 PCS.
(/3
13
00150
.0022
12
12
.10
10
47
07
FKM CAPACITORS
.022nd
0471111
13
21
17
17
.08
.13
741575 69 7415157 55 .12 10 27 23 .17
741504 35
741516 49 741,5162
1

2 25 3.3/ 39K 47K 5.6K 58K rei .004701

.0141 12 10
07
07
.1101
.22011 33 27 22
741505 35
741508 29
141083 1 15 7415163 2 25 ,ASST. 4 5 ea. S 2: 10K 125 156 8x 1/4 WAIT 5% 56 PCS +28% 016600 TANTALUMS(801.10) WALTORS
741610 9 741585 2 49 7415164 1 95 CL. 22/ 27K 33K 396 474 .1/350 28 .23 .17 1.5/350 30 .26 21

741513
741514 175
69 741586
741590 1
49
25
74L5175
7415181
1-95
3 69
r/i ASST. 5 5 ea. 567 680 32K 1006 170K 154 WATT 5% 50 PCS 1- .15/350
.22/35V
28
28
23
23
.17
17
2.2250
3.3250
.31
.31
.27
.27
22
22

741520 29 741592 1 25 7415190 295 150; 196 220K 270e 330K .33/350 28 23 .17 4.7250 .32 28 .23
741526 39 741593 125 7415191 2 85 ASST. 6 5 ea. 390/1 4706 55501 680K 620K 1/4 WATT 5% - 50 PCS. .47/350 28 23 .17 6.8250 36 .31 .25
741527 9 741.595 1
95 7415192 2 65
IM 1.2M 15M 15M 22M .9/350 .28 23 .17 10250 .40 35 29
741528 39 741596 1 89 7415193 2 85 1.0/35V .28 23 .17 15/25V 63 .50 .40
7410107 59 7415104 19 ASST. 7 5 ea. 2.790 3 3M 3 9M 4 7M 5 6M 1/4 WATT 5% 50005.
MINIATURE ALUMWUM ELECTROLYTIC CAPACITORS
741530 29
741532 39 74L019 59 7415195 19 ASST. 8R Includes Resistor Assortments 1-7 (350 PCS.) $7.49 ea. Axial Lad RAdIAI lud
741540
741551
39
29
7415112
7415132 1
59
25
7419257
7415260
1 75
55 $5.00 Minimum Order U.S.. Funde Only
-- Spec Sheets - 25c - -
Send 35c Stamp for 19774 Catalog
47/500
1.0/50
15
16
13
.14 .11
10 .47250
471506
1.0/160
IS
.16
13
14
10
II

ames
741555 29 7415136 59 7415279 79 3.3/50V .15 .13 10 15 .13 .10
California Residente Add H% Sales Tao Dealer Discount Available Request Pricing
7eI571 ao 741_5138 1 89 7415670 3 95 4.7256 .16 14 12 1 0250 .16 .14 .11
10259 .15 13 .10 1.0150V .16 .14 ,11
CLOCK CHIPS 10/500 .16 .14 12 4.77566 15 13 10
MM5309 6 Dp6,
BCD Outputs, Reset PIN. 9.95 22259 .17 15 .12 4.725V 15 .13 10
MM5311 6 Digit. 800 Outputs, 12 or 24 Hour 4.95 22/50V .21 .20 18 4.7/50V .16 1/ ,11
MM5312 4 Digit. 8C0 Outputs, I PPS Output 4.95 47/25V .19 .17 .15 10/169 .14 12 .09
MM5314 60058. 12 or 24 Hour. 50 or 6010 4 95
47/500 .25 .21 .19 1025V .15 .13 .10
MM5316 4 11408 Alarm. PPS Output
1 6 95 100/255 .24 20 .18 10/508 .16 .14 12
MM5318
07791
8400 Clock Chit. For Use With (MM5841
6 01011. Galatar, Alarm, 12 or 24 Hour

DATA HANDBOOKS
- 58 951 9 95
5.95 ELECTRONICS 19/50
220/253/
220/500
35
32
.45
.30
.28
.41
.25
.38
28 47/500
19/19
100251/
24
.19
.24
21
.15
.20
.19
.14
18

`inaa
7400 Pin.out & Description of 5400/7400 ICS 02.95
CMOS Pin-out & Description of 4000 Series ICS $2.95
6í0,0M& Functional Description
ALL THREE HANDBOOKS56.95
$2.95
1021 -A HOWARD AVE., SAN CARLOS. CA. 94070
PHONE ORDERS WELCOME (415) 592-8097
All Advertised Prices Good Thu July
- 470/25V
1000/16V
2200/16V
.33
.55
.70
29
50
.62
.27
.45
15
10/50
220/169
470259
35
.23
31
.30
-17
28
2P

110 POPULAR ELECTRONICS

 Pert"*
COlA
CY2A
.,5:'CRYSTALS THESE FREQUENCIES
Frequency
1
000 MHz
2 000 MHz
ONLY
Case /Style
HC33 U
HC33 U
1V`'- Price
55.95
$5,95
8080A CPU
8212
8214
MICROPROCESSOR COMPONENTS
8 Bit Input /Output
Priority Interrupt Control
$19.95
4.95
15.95
8228
MC6800L
MC6820L
System Controller - Bus Driver $10.95
8 Bit MPU
Periph. Interlace Adapter
35.00
15.00
0 Timeband
Digital Alarm Clocks
C030 4.000 MHz HCi O L 54 95 8216 Bi- Directional Bus Driver 6.95 MC6810AP1 128 x 8 Static RAM 6.00 24 -nour alarm
CY7A 5.000 MHz HC18 /U 54 95 8224 Clock Generator /Driver 10.95 MC6630L7 1024 x 8-Bit ROM 18.00 Ooze Button
05120 10 000 MHz HOlYU 5495 CDP1802 - with user manual 39.95 Z80 CPU 49.95 00
CY14A 14 31818 MHz HC16U 54 95
CV79A 18 000 MHz CPU -S RAM S
HC18U 54 95 I
Silo,
CY22A
CV30B
20 000 MHz
32 000 MHz
0018
HC18
U

U
54 95
54 95
BOBO
8080Á
8009
Supe: 9008
24
19 95
95
2101
2'02
256
256x4
1024
x

x
1

1
Stau;
Sta.
Sane
S
5
I

175
49
95
2.500 - Ivory Case
AM
5E2222_
F4
7
1JI11+ C 8211
2'07'S280 4096xt Dvnam,_ ct 0,27277
SR'S 4 95 0.5008 . Ebony Case Woodgraln Case
OR- 2206KB Kit 529.95 Special XR- 2206KA Kit $19.95 2504 '024 Dyr'.m¢ 5 3 95 256 x _ 578,2 6 956

WAVEFORM
2518 9cx 32 E'1 2 02 4g9 212,2 $16.95 One year fa -tory w.2..,nI $19.95
Hr
EXAR
TIMERS .,^. 51' 256 . 4 6 95
GENERATORS 1R -555CP
2 Aó 2,6x4 513, 6.95
*R 205
cut 22n6CP
$8
1
4O

is
5R -3205
R- 556CP
3 95
8599
91La2
ta.4
1024 x
Static
Stour 2 25
3 49
DIGITAL AUTO INSTRUMENT
SEVEN DIFFERENT INSTRUMENTS!
1

MISCELLANEOUS vR 295605
BIT 405 4200 256x1 Saus
2R 224005 C.3 8ts PI" 95 93421 256 Saue MEETS OR EXCEEDS ORIGINAL AUTOMOTIVE SPECS.
x 1
95
STEREO DECODERS PHASE LOCKED LOOPS 1024 Siam Special 5.95 IMM5262 2Kx1 Dynamic 2Io, i pJ0 Please spoof!), which one of the seven models you wart
SR 210 run when ordering -these do not all cane In one unit.
5 n5 PROMS
Ito 465 , 80 0R -215 6 Fri 16. 4 Rnn 9 95 992A 224B S 995 Each model must be bought separately.
4.I8WP 320 xR 14851 4 80 9e -56705 95
i
5209 2048 femos '495
2 99 +.i 2208 5 20 4R 567CT 70
82529 TACHOMETER 4 SPEEDOMETER'
SART'S 32 8 0415 C 5 OIl
0-99 MPH
30s Baue 55 95 82612 32 x 8 0.1115 5 Lw 1 0-9900 RPM
:5287 1024 Sr cc 2 95 4, 6 or 6 Oyu nders
CONNECTORS RUM'S
3601
708
258
8K
x 4 Fast
Fprom
395
2 WATER TEMP.
5 OIL PRESSURE
0.60 PSI
2513121401 Char Gen upper case 995
PRINTED CIRCUIT EDGE -CARD 2513130211 Char Gen -lower case
S
9 95
6301-1 1024 iiiState Bipolar X7.19 100-250 F
6 OIL TEMP
C230 1 256 Coen Cpneclo, Bloom 2 95

-
156 Spacing -Tin- Double Read -Out 200-350
2516 Chat Gen 10 95 F
25, T-State Bipolar 295 FUEL LEVEL
Bifurcated Contacts Fits 054 to 070 P.0 Cards 3 Percentage
Low Fuel indicator
BATTERY MONITOR
15)30 PINS (Solder Eyelet) $1.95 AY-3-850111 516 95 SPECIAL REQUESTED ITEMS B197 200 7 - Volts From 1115 SOC
1

18/36 PINS (Solder Eyelet) $2.49 MC3061P 3 50 004505 6 75 825115 25.00 3341 6.95 BRIGHT YELLOW ORANGE
MC4016P 7244767 7 50 C04515 6 50 5841 9.55 9368 3 95
22/44 1" FD DISPLAY!
50,100 1
PINS
100 Spacing) PINS
(Solder
(Solder
Eyelet)
Eyelet)
$2.95
$6.95
MC14583
MC14562
3 50

14 50
004520
MCM651
2

17.50
70 MK50240
11090
17.50
19.95
MC1408L7
L011O m111 25.00sel
9.95
Kit includes case bracket and all components
Nothing else to buy' 12 Volt NEG ORO.
1

- complete
COA059 9 95 MCM6574 17 50 050026CH 3.75 A1-5 -9100 17 50 ea
25 PIN -D SUBMINATURE 004070 95 MCM6575 17 50 TIL308 10.50 95990 13 95 DIMENSIONS db x4 a 2 KIT $49.95
D625P PLUG $3.25 ALLOW
Add $10.00 for required speed transducer ASSEMBLED: $59.95
TO 3
PARATRONICS
1

D625S SOCKET S4.95 WEEKS DELIVERY

Featured on February's Front Cover of Popular Electronics DIGITAL STOPWATCH
31/2 DIGIT DVM KIT Bright 6 Digit LEO Ds 2.707
Logic Times to olleTu5959seconds
59 noO Tune Bast
Crystal Controlled

Analyzer Kit MODEL

Three Stopwatches in One
Times single Event
Sae45 x 2.
-
Split 8 Taylor
0' (4'n ounces)
100A
$189.00 /Kit
Uses

Kit - -
Assembled
3 Penile Cells

$39.95
$49.95
'

this 0 -2 las05 per cent digital voltmeter features the Motorola 314r digit
DVM chip set II has a 4 LED display and operates Irom a single 5V
Analyzes any type of digital system
Checks data rates in excess of 8 million Troubleshooting microprocessor -
Some applications are: Heavy Duty Carry Case 55.95 L

power supply the unit is provided complete with an mlection molded black
plastic case omplele with Bezel An optional power supply is available
words per second
Trouble shoot TTL. CMOS, DTL, RTL,
address. instruction, and data flow
Examine contents of ROMS -- Stop Watch Chip Only (7205) $19.95
which tits into the same case as the 0-2V DVM allowing 117 VAC operation.

A. 0 -2V DVM with Case $49.95

Schottky and MOS families
Displays 16 logic states up to 8 digits wide
Tracing operation of control logic
Checking courier and shift - ELECTRONIC `PENDULUM' CLOCK
B. 5V Power Supply $14.95
e

.
See ones and zeros displayed on your
CRT. octal or hexadecimal format
Tests circuits under actual operating
register operation
Monitoring I/O sequences
Verifying proper system operations
-- Swing Pendulum
.7' Hours and Minutes Display
12 or 24 Hour Mode

Etching Kits
32 X A -1 P C. Etch Materials Kit $29.95 ea.
conditions
Easy to assemble - during testing
comes with step -by -step construction manual
which includes 80 pages on logic analyzer operation.
Time Set Push Buttons
e Alarm Feature
Kit -unfinished $59.95
enough f Al 5 circuit boards (case unassembled)
27 X A -1 Etched Circuit Kit S 9.95 ea. Assembled -stained $69.95
-
6

Plughoards complete 1[t only all ware, BUGBOOK ;+

(case assembled)
3662 65 X 45 X 1' 16 Epoxy glass S 6.95 ea. Continuing Education Series
P Panern-44 P C Tabs.spaced 156 QUARTZ DIGITAL AUTO CLOCK
8800V Universal Microcomputer /Processor $19.95 ea.
BUGBOOK I & II -Basic concepts of TTL Logic -over 90 OR ELAPSED TIMER!
piugboard -Epoxy Glass- complete experiments 517.00 /set
with healsink and mounting hardware
5.313 X 10 X 1/16 copper clad
BUGBOOK Ila - Introduces UART
for RTTY enthusiast
- recommended
Elapsed Timer: Hrs, Mins and Secs
12 or 24 Hr Capacity

-
55.00/book Simple Reset - Start Pushbutton
1/16 VECTOR BOARD Control

.... 0 1' Hole Soaping

Pad No L
PRanern
W 1
Price
2Up
BUGBOOK III - Explores 8080 chip introduces
Mark 80 Microcomputer 515.00 /book
Complete kit
ca and all
Includes mounting
components.
buy Features MM5314cn,p Large 4' LED's
nothing else
bracket.
to

4
50
50
50
n 50
1,
6 50
00
2
1

' 69
,2

0:
a
1
42
16
EXPERIMENTS -
555 TIMER APPLICATIONS SOURCEBOOK WITH
over 100 design techniques $6.95 /book
Accuracy Decal than _ min per m0. internal
hanery 005up 12 volt non -polar operation
Kit: $29.95
.150 x50 256 2':,t CMOS -M- DESIGNERS PRIMER AND HANDBOOK C MTV, DNS 4' x 4 a 2'.
450 Ì, DO 504 45: complete CMOS instruction manual '4 HOUR MODE Assembled: $39.95
a 56.00

lrodumory Otte, -
SPECIAL
all 6 books
- S42.95
¡worth $19 9E'
CASE ONLY (includes hardware. mounting bracket and bezel; $6.50

HEAT SINKS Tne3E 700,5 a low cost M0772121°01, Sill

205-CB s.2s
CONTINENTAL SPECIALTIES IS very bon quality unit The opt lea
a simulated walnut case with Il

291 -.36H PROTO BOARD 6 Othe, CS Proto Boards PROTO CLIPS

enslons of x Cl x II utilizes 1

$ 25 MAN72 nigh brightness real ut and inn

680. 75A 51.50 $15.95 PB100 - 4.5" x 6" $ 19.95 14 PIN 04.50 MM531.i clock Ill
HEXADECIMAL ENCODER 19 -KEY PAD
(6 long X 4 wide) PB101 - 5.8" e 4.5"
PB102 - 7" x 4.5"
29.95
39.95
16 PIN
24 PIN
4.75
8.50 115 VAC $17.95
. 1 0 PB103 - 9" x 6" 59.95
DESIGN MATES
. ABCDEF PB104 - 9.5" x 8" 79.95
DM1 - Circuit Designer

-
Return Key PB203 - 9.75 x 61/2 e 24/4 75.00
PB203A - 9.75 x 622 x 23/4 120.00 54.95
Optional Key ¡Period)
- KPy
ndudes power supply) DM2 - Function Generator
69.95
DIGITAL CLOCK KIT
4 DIGIT KIT $49.95 4
31/2 INCH
DIGIT ASSEMBLED $59.95
DIGITS
Logic Monitor $04.95 DM3 - RC Bridge
6 DIGIT KIT $69.95 6 DIGIT ASSEMBLED 579.95
$10.95 each 59.95
This clock features big 344" high digits for viewing in offices, auditoriums.
0 type ',kolas poca
etc. Each digit n formed by 31 bright 0.2" LED's. The dock operates from
OT PROTO STRIPS OT- 59S 590 12 50
63 KEY KEYBOARD O -598 bus slop 2.50
117 VAC, has either 12 or 24 hr. operation. The 6 digit version is 27" x
Esl,i 0 -47s 470 1000 31 "X11° and the 4 digit is 18"x344° x t1/2 Kits come comeletewer
.-,.; 00.595
b1 IBS o '475 bus strip 2.25 all components, case and transformer.
k6i 0 -355 350 8.50
0T 598
Specify 12 or 24 Hour When Ordering
0 758
$19.95 k15idRp.X,li1 I
'` * 4/S
111 07.123 0 .18$
bus strip
180
2.00
425
.3I1.IWMIgYKN1fhKNlep44.
;4.
0 .125 120 3.75
JE803 PROBE
Hos165 16 LINE TO FOUR BIT PARALLEL KEYBOARD ENCODER 37.95 CT 8S
0 -S5
aT-75

Experimento, 300
80
70
3.25
300

$ 9.95
The LOglc Probe's
lnoespenslble ,n
a

trouble
uml which it lu, the most pan
snow,, iodic lamines
"- J
JOYSTICK OT 75
Experimentor 600 510.90
TTL OIL. RTL- CMOS it Cenres the power u
needs 70 [Wale directly on o1 Inn Otcu't under
"wax,-

-- - -
These loysticks feature lour
test draw' g a Scam 10 mil ma. ,t es a MAN:
$5.00 Minimum Order 0.5. Funds Only Spec Sheets 25e Send 355 Stamp lot 1977A Catalog
potentiometers, that vary re- readout to indicate any or the tdiowng stales by
California Residents Add 6% Sales Tax Dealer Discount Available Request Pricing

ames
sistance proportional to the !new symbots 2691- 11Law1 [,PULSE, -P Tne

angle of the stick. Sturdy metal

prone Can defect alga.men iy pulses to 45
11 can I On used at M05 levels or circuit damage
mag
9 95 Per Kit
construction with plastics wig resuiI printed circuit board
components only at the mova-
ble joint. Perfect for electronic TeL 5V 1A Supply
ELECTRONICS

fit
games and instrumentation. This is a standard OIL power supply using the Meli known
LM309K regulator IC 10pr0vde a solid AMP of current at
*5K Pots $4.95
1

Special

*100K Pots $7.95

1021 -A HOWARD AVE., SAN CARLOS, CA. 94070
PHONE ORDERS WELCOME (415) 592 -8097
All Advertised Prices Good Thru July
- volts We try to make Wings easy for you by p1554109
everything you need in one package, ,nciud,ngtne tiaraware /
for only
$9.95 Per Kit J
CIRCLE NO 25 ON INFORMATION
JULY 1977 FREE CARD
111
 TAPE-SLIDE SYNCHRONIZER, lap -dissolve, multipro-
¡actor audiovisual plans $8.50. Free Catalog. Millers, 1896
AMAZING ELECTRONIC
REAL ESTATE

BIG...FREE...CATALOG! Over 2,500 top values coast to

Maywood, South Euclid, OH 44121.

BUILD ELECTRONICS DEVICES in your home. Get started

Experience not neces- - !LASERS
ERS
V. PRODUCTS ..4
SUPER POWERED, RIFLE, PISTOL, POCKET SEE IN DARK PYRO-

in your spare time. Big Profits CHHICAL DE- 80GONG.UNCRAMBLERS. GIANT TESLA. STUNWAND - TV
DIS RUPTER . ENERGY PRODUCING, SCIENTIFIC DETECTION, ELECTRIFYING
coast! UNITED FARM AGENCY, 612-EP, West 47th, Kansas sary. Write for free literature telling how. Electronics CH EMICAL, ULTRASONIC CB, ÆR0, AUTO ANO MECH DEVICES, HUNDREDS
City, MO 64112. Develop Lab., Dept. D, Box 1535, Pinellas Park, Fla. 33565. MO RE ALL NEW [LOS UNITO PARTS SERVICE.

INFORMATION ttaQitnitrd
CA TALOG SI Boa 626 Lord leHery P2. Amherst. N.H. 03031
RUBBER STAMPS PLANS AND KITS

RUBBER STAMPS, BUSINESS CARDS. Many new prod-

MIXERS
Plans -- Preamps -
Speakers. Top Quality Kits
Parts. Send 25 cents for catalog. Audio Design &
-
ucts. Catalog. Jackson's, Dept. K, Brownsville Rd., Mt. POCKET COLOR/BAR GENERATOR kit, 16 patterns,
Engineering Co.. P.O. Box 154, Lee, Mass. 01238. (413)
Venon, III. 62864. $49.95. Plans, $4.95. Workshop, Box 393PC, Bethpage,
243 -1333.
New York 11714.
FIVE OCTAVE Touch Sensitive Electronic PIANO Kit.
DO -IT- YOURSELF
Components $245 airmail U.S.A., Canada. Clef Products,
31 Mountfieid Road, Bramhall, Cheshire, England. TIGER SST
MODULAR TELEPHONES now available. Sets and com- CONVERTER KIT: Two meters to AM Broadcast, $8.95 ppd. SIMPLI -KIT
ponents, compatible with Western Electric concept. Cata- Send stamp for flyer. Electronics Hobbies, 3421 Hawthorne
log 50 cents. Box 1147W, San Diego, California 92112. Rd., Gainesville, FL 32601.
MODE 8 -8 channels TTL on ANY scope plus triggered FORTY CHANNEL CONVERSION Kit fits all 23 channel AM
memory logic probe. Kit $52.50; plans $5.00. BASIX, 1067 rigs. 40 Plus, 11301 Melody 308, Northglenn, Colorado
Seneca, Bethlehem, PA 18015. 80234.
FOR
THE DO- IT-YOURSELFER
NOOW!a high quality CD Electronic
AUTO BURGLAR Ignition System in kit form.
12OR24 -HOUE; OPERATION
ALARM KIT 12 VOLT AC or DC POWERED
MODEL Contains all components and solder to
build complete Solid -State Electronic
001
SIX LARGE CD Ignition System for your car. As-
KIT UALR -1 sembly requires less than 3 hours.
$9.95
ITS Increases MPG 15% Eliminates 4 of 5 tune -ups
Increases horsepower 15% Instant starting, any

S
KrPlZNnNG BRACKET Plugs and Points last weather
INCLUDED
MALR -1 WT 50,000 miler. Dual system switch
WIRED &
Y
"
7aK1'1 3 pq Fits only 12 volt neg. ground . Only $21.95 postpaid
TESTED
$19.95
ASfEMeLEO
oE
WrT7S
MONE
A P AC
two 2.7W Star Corporation
P.O. Box 1727 Grand Junction, Colorado 81501
tssw ro or"ea.v,s
"no
41391130.
V
BATME I FA.
AN EASY TO A SSE MSLE ANO EASY TO INSTALL EA MORE #137pfA
ALARM PROVIDING MANY FEATURES NOT
NORMALLY FOUND. KEYLESS ALARM MAS EA. FREE KIT Catalog contains Test and Experimen-
PROVISION FOR POE. S GROUNDING R WlrA
SWITCHES OR SENSORS. WILL PULSE HORN OP AMPS
uTY
ter's Equipment Dage Scientific Instruments,
RELAY AT 012 RATE OR DRIVE SIREN. KIT
PROVIDES PROGRAMMABLE TIME DELAYS
FOR EXIT. ENTRY ALARM PERIOD. UNIT
3/11.00
DIODES Box 1054P, Livermore, CA 94550.
MOUNTS UNDER DASH - REMOTE SWITCH 301 TO -5 IN4002 1A.100PIV 1241.00
CAN BE MOUNTED WHERE DESIRED. CMOS 709 DIP IN4006 1A,8COPIV 11/$1.00
70e TO 5

WERE! KITS
RELIABILITY RESISTS FALSE ALARMS S IN 4007 1A,1000PIV 10/41.00
PROVIDES F011 ULTRA DEPENDABLE 741 DIP RECTIFIER 2.5A,1000PIV 4/41.00
DO NOT BE FOOLED BY LOW PRICES! THIS IS A 741 M DIP
TOPOUALITY COMPLETE KIT WITH ALL PARTS PROM IN914 SIL. SIGNAL 20/41.W
741 TO -5
INCLUDING DETAILED DRAWINGS ANO IN. SIL. SIGNAL 20 /$1.00
STRUCTIONS OR AVAILABLE WIRED AND 1702 E Prom 15.95 747 TO5
IN 4148
DVAC 28V. 4/51.00 INOrgans, Pianos
Strings
TESTED. 5203 E Prom $8.96 Rhythms, PA Systems
DISCRETE PC TRIM
JUMBO DIGIT CLOCK KIT
A complete Kit (less Cabinet)
JUMBO DIGIT
CONVERSION KIT
$ 9.95ea.
LED's
DIGITAL
CLOCK IC's POTS
104 -page catalog $2
featuring: six .5" digits, MM5314 IC Convert small digit LED clock to JUMBO RED MM5312 8 495 25K 6151.00 WERSI electronics, Inc.
12/24 Hr. time, 50/60 HZ., Plug large .5" displays. Kit includes 6 - .5" MM5314 395 4 7K 6/51.00
Dept.A2, Box 5318,
i
-

Transformer, Line Cord, Switches LED's, Multiplex PC Board & easy MM5375AB 3.95 SPECTNOI,
Lancaster, PA 17601
and all Parts. (Ideal Fit in Cabinet Ili hook -up info. CT 7001 795 10E 10 TURN

Kit #5314 -5.... $1995 9w3ß Kit # JD -1CC For common Cathoce 10$1 CO CT7002 13.95 95c
WITH PCB rder
. ea Kit # JP -1CA for common Anoc 100 FOR $9 50 MM5369 2.50 4153.00

PLEXIGLAS HL VARIABLE REGULATED

00 ea. CABINETS
60
XTAL TIME BASE
Will enatrce
1 AMP

POWER SUPPLY KIT

EMPLOYMENT OPPORTUNITIES

Great for Clocks

Digital Clock Kits VARIABLE FROM 4 to 14V ELECTRONICS/AVIONICS EMPLOYMENT OPPORTUN-
or any LED Digital SHORT CIRCUIT PROOF ITIES. Report on jobs now open. Details FREE. Aviation
project. Clear-Red or Clock -Calendar
723 IC REGULATOR Employment Information Service, Box 240E, Northport,
Kits to operate 2N3055 PASS TRANSISTOR
CABINET Chassis serves as
I from 12V DC. New York 1176E.
3 "H,6%1N,534" D
Bezel to increase
contrast of digital
1 "x2"PCBoad

PowerReq:
SV
CURRENT LIMITING AT 1 Amp
KIT IS COMPLETE INCLUDING
DRILLED a SOLDER PLATED
OVERSEAS JOBS
Computerized Reports
--
FANTASTIC PAY! All Occupations.
$2.00. TRANSWORLD, Interna-
displays.
CABINET II (2.5MA TYP.) FIBERGLASS PC BOARD AND
tional Airport, Box 90802 -N, Los Angeles, Calif. 90009.
234 "H,5"W,4 "D
Black, White or
Clear Cover
Easy 3 wire hookup
Accuracy:
± 2PPM
ALL PARTS (Less TRANS-
FORMER) KITSPS -01 $5.95
TRANSFORMER 24V CT Will -
ROCKY MOUNTAIN JOBS!! Colorado Idaho -
Montana
Wyoming!! Free details. Intermountain -S7, 300 Dundee,
-
TB -1 (Adjustable) provide 300MA at 12V and Boise, Idaho 83706.
NEW LSI TECHNOLOGY omplete Kit
$4115 1 Ampat5V with IPS- 01.83.50

FREQUENCY COUNTER it & Cal 59.95 RED OR GREY PLEXIGLAS MISCELLANEOUS

KI 3 "x6 "x1/8"
8 LARGE .4" RED SET CF 6 FND -359 FOR DIGITAL BEZELS
BOAR95
LED DIGITS WITH MULTIPLEX PC WINEMAKERS. Free illustrated catalog yeasts, equipment.
ONLY 8 IC's! XTAL TIME
955 ea. 4/$3 Semplex, Box 12276P, Minneapolis, Minn. 55412.
A crut Y "Slate
of the Art" counter BASE Fairchild Super Digit
components throughout. using quality 25 AMP BRIDGE
KIT INCLUDES:
DETAILED INSTRUCTIONS, RID-359 $1.95 ea.
TOP QUALITY 4" Char. Ht.
FIBERGLASS DOUBLE XTAL, 7 segment LED 3/$5.00
BOARD, IC'S WITH SIDED PC RED
POWER SUPPLY SOCKETS AND ALL Direct Pin
AND CABINET. PARTS LESS Pie 100 PIV
"Placement fer
50 MHZCOUNTER popular FND70. Everything you want to know-need
KIT #FC
5 VOLT REGULATED
/ AMP 589.95 NYLON WIRE TIES know-about CB, Ham Radio,
to
POWER SUPPLY 95¢ ea, 1059.50 8" TIE-WRAP 100/81.95 Listening, Police -Fire Monitoring,
SW
KIT 100/81.75
350MHZPRESCALERKIT MPS-02 23.95 1001579,00 4" TIE -WRAP Marine Radio. Features, specifica-
850 MHZ PRESCALER PS-350
L-3 23.95 tions, latest prices and photographs
KIT MOLIEX IC SOCKETS of equipment on the market are at
CABINET [A MFG HARDWARE SCAB $29.95
[CABINET WILL HOUSE MPS-02 PINS 1441,1 PINS 14 25 100 your fingertips. Order your copy from
#FC -SD, $19.95 Form Inexpensive 8 5 25 522 S 20 Communications Handbook, Consu-
PRESCALER] 02, AND A Soeïeta 14 .25 .22 20
16 28 25 23 mer Service Division, 595 Broadway,
DELIVERIES TO START 100for$1.25 18 .31 .28 .26 New York, N.Y. 10012. Enclose
IN MAY, 1977 .45 $2.50 ($1.95 plus 55c for postage
Reel of1000 -$8 24 50 .40
28 60 55 50 and handling). Outside U.S.A.
40 75
ORDER BY PHONE OR MAIL Orders Under $15 Add $1.00 Handling
70 65
$3.00, postpaid. Residents of CA, CO, FL, IL, MI, MO,
COD O'DERS WELCOME FI. PI-.. Sales Tax.
-
NY STATE, DC and TX add applicable sales tax. Postage
and handling clarges non -taxable.

BANMAMERICARD
BOX 219 HOLLYWOOD, FLA. 32022 (305) 921 -2056

WE PAY ALL SHIPPING IN CONTINENTAL USA - OTHERS ADD 5% [10% FOR AIRMAIL]
POPULAR ELECTRONICS
CIRCLE NO 35 ON WEE INFORMATION CARD
 SOLVE YOUR TEST CONNECTION PROBLEMS WITH EZ-HOOI(
E -Z Hookshave been designed and field tested throughout the industry to save time and money in commercial electronic production and servicing. The
spring -loaded hook attaches firmly, yet so gently it will not damage component - frees hands while testing. Durably constructed and fully insulated to a
single contact point assuring true readings. Meets exacting laboratory and space age computer technology requirements. AVAILABLE IN 10 RETMA
COLORS: Red, black, blue, green, orange, yellow, white, violet, brown or gray.
Jumper with X -100W Mini Hooks EXTRA LONG MINI HOOK
Order No. Length Price JemPer ,vilh %M Mero )oaks XL -1 Mini Hook 15.0" long) combines all the proven features of the X100W
204 -12W 12" 51.60 0.4e. No. Lene& Pike with an extra long body. It will mate sate. Nat -free not con actions in ORDER Pin %L1
204 -24W 24" 1.60 20.7CM.12 to 51.70 Card racks end through deep wiring nest up to 4". 31.25 ea
2040M.24 24" 110

1100
Specify color To111111 Swift, cow. ea-
JUMPER WITH
XL -1 MINI HOOKS Order No. Length Price
MICRO
204X11 -12 12' 52.80
204X11 -24 24" 2.80

Y
OM Micro soak It 75" lone, < Own) t
Iw alleull IC Tenons amain nooxver JUMPER, XL -1 MINI HOOK TO STACKING
to Wow wow wan wwpit and lever
BANANA PLUG
Jumper with X -100W Mini Hook
Order No.
201XM
Length
32"
Price
S1 40
yesmw dslnap COMM.,
Scarify calm.
MINI HOOK
4.110 w.

ORDER PIN 0M Specify color

Order No.
201X1-t'
Length
32"
Price
51.95 I i

'Specify color 'Sowre hole tip for hoo ing laterally to leads or vertically Over Vitale wire -wrap pins.
9f ß^--11
Jumper X -1013W Mini Hook' ORDER YOUR XM -S MICRO HOOK SET
to Stacking Banana Plug X10011/
reaped
M,n, soak 1225 "" ione) rune TODAY! (Includes 1 ea. red, blk, blue, green,
Hp
E-Z-
= =
Order No. Length Price onnIO011 oh; Korange, yellow, white, brown, violet and gray
201w 32" Si 35 test Nook n Lariano, Micro Hook). At this low price you can afford
for component was of 4
g,
to art into tight piste 5.75 w. more than one set.
SPec.h co., ORDER P/N 0100W COMPLETE SET 110) MICRO HOOKS - $7.95
CONTINENTAL SPECIALTIES CORP.
PROTO -BOARD UNITS The Solderless Breadboarding System
SOCKETS & BUS STRIPS That Saves You Hours On Every Project LOGIC MONITOR 1
Plug -in wire. test, modify or expand without patch cords or Like our OT system, Proto -Board units let you assemble, test and modify
solder. Snap together to form breadboard needed. circuits literally as NM es you can think. Rugged, heavy duty construction Simultaneously displays
PN /Description Terminals Price for use in engineering laboratories, in educational institutions, on production static dynamic logic Stites
lines, etc. of DTL, TTL, HTL or
01595 Socket 118 512.50
0T598 Bus 20 2.50 PROTO -BOARD 6 KIT- Complese, List P $ 1 5 . 96 CMOS DIP ICs. Pocket
One preauembled OT -47S socket. two preassembled OT -478 bus strips. four size $74.95
0T47S Socket 94 10.00 four 5 -way binding posts end all hardware.
0T478 Sts 16 2.25
0T355 Socket 70 8.50 $19.96
To
w preessembd le -35S sockets , one l pressMmbi d OT -36B bus stript
07358 Bus 12 2.00 5 -way binding posts and all hardware.
0T18S Socket 36 4.75 LOGIC MONITOR 2
OT12S Socket PROTO -BOARD 101- Complete. List Price $29.96
24 3.75 Fully assembled breadboard contains two 07 -35S sockets and four 07-358
OT85 Socket 16 3.25 bus .rips mounted on metal ground /base pieta with non -marring feet. Displays static and dynamic
OT7S Socket 14 3.00 Excellent for audio and small digital protests. states of digital ICs such a
CMOS, HTL, TTL, OTL d
PROTO-BOARD 102 -Complete. List Price $39.96 RTL. Selectable threshold
Fully assembled breadboard contains two OT -47S sockets, three OT -470 bus
strips and one OT -358 bus strip. Excellent for intermediate digital needs. Control $124.95
PROTO -BOARD 103 -Complete. List Price $59.95
Fully assembled breadboard contains three 07 -595 sockets. four OT-5958995
One 01-47B bus strips. plus four 6 -way binding posts. Build caleuietors
interfaces. networks, etc.
PROTO -BOARD 104 -Complete. List Price $79.95 LOGIC PROBE LP -1
Fully assembled breadboard Contains four 07-69S sockets. seven OT -598 bus
PROTO -CLIP strips end four 5 -way binding posts. Build CP U. encoder. complex display, arc
For power- on/handt off signal tracing. Bring IC leads up from PROTO-BOARD 203 -Complete. Litt Price $75.00
Proto -Board flexibility Plus built -in 1% regulated 6 VDC, 1A supply, 2250
PC board surface for fast troubleshooting.
All the features of the PB -203 Plut traditions! power supply flexibility: oro
PC14 14-pin S 4.50 oldes 1 %- raguiaisd 5 VDC suppiv: regulated separate .15 VDC and -15 VOC
PC16 16-pin 4.75 0.5A supplies. each with internally and independently adjustable Output
8.50 voltage', ripple and noise of o and -15v suooim, 10 mV at 0.25A.
PC24 24-pin
PC40 40-pin 13.75 bided..t ti-
points, twenty -four 14 -pin dip sagacity. Compact, circuit-powerad multifunction logic probe. Muir,
Family competability, DTL/TTL /HTL /CMOS. Traces logic levees
PROTO -BOARD 203A- Compute. List Price $120.00 grad
pulses through digital circuitry $44.95
CARBON FILM RESISTORS 15 %1
Only in Multiples of
RESISTOR KITS
100 pcs per value (ohms) 5%CARBON FILM MATSUO HYBRID
14W... 51.59 per 100 RESISTORS DIPPED
%W.. -$1.79 per 100 AUDIO
10 100 1.0K 10K 100K 1,0M
TANTALUM POWER
11 110 1.1K 11K 110K 1 1M CAPACITORS AMPLIFIERS
12 120 1.2K 12K 120K 1.2M MF V MF V
S
13 130 I.3K 13K 130K 1.3M 35 33 6.8 16 .40
15 150 11K 15K 150K 1.5M
1
Multi- purpose linear amplifiers for comercial end indus'
15 35 .33 6.8 35 .45 'rate) app!icautions.
16 160 1.6K 16K 160K 1.6M 22 35 33 10.0 16 .42
18 180 10K 18K 180K 18M .33 35 33 100 25 45 Less than 0.5% harmonic distortion at full power level.
20
22
200
220
2.0K
2.2K
20K
22K
200K
220K
2.0M
2.2M COMPLETE WITH .7 35 33 10.0 35 .90 1/2 dB response from 20 to 100.000 Hz.
24 240 2.4K 24K 240K 24M STORAGE BIN
68 35 33 150 20 45
1.0 35 33 15.0 35 1.32 Smgle or split (dual) power supply.
27 270 2.7K 27K 270K 2 7M
30 300 10K 30K 300K 3.0M 1/4 WATT KIT 1.5 35 40 22.0 16 .45 Rugged, compact and lightweight packages.
2.2 20 33 33.0 20 1.32
33
36
330
360
3.3K
3.6K
33K
36K
330K
360K
3.3M
3.6M
42 Different Velues
(6852 to 4.7 M2)
2.2
3.3
35
35
.40 70
.42 68.0
20 1.53
Built -in current limning for SI -1050G and efficient heat
radiating construction.
16 1,62
39
43
390
430
3.9K
4.3K
39K
43K
390K
430K
3.9M
4.3M
20 Each Value .7 35 45
TYPICAL CONNECTIONS
7 470 4.7K 47K 470K 4.7M 1/2 WATT KIT
PLESSEY SI. 1050G WITH SPLIT SUPPI Y
51 510 5.110 51K 510K 5.1M 42 Different Values
56 560 5.6K 66K 560K 5.6M POLYESTER SAN KEN Series SI -1000G amplifiers LEFT
620 6.2K 62K 16812 to 4.7 MS21 ere self- contained power hybrid am-
62 620K 6 2M (CAPACITOR)
68 680 6.8K 68K 680K 6.8M 20 Each Value MINI BOX plifiers designed for Hi -Fi. stereo,
75 750 1.5K 75K 750K 7.5M MF V 5 MF V S musical instruments, pudic address
1/4W - $24.90 PER KIT 001 1000 .14 .039 250 .15
82 820 112K 82K 820K 8.2M systems and other audio applications. o
91 910 9.1K 91K 910K 9.1M 1/2W -- $25.90 PER KIT 0012 1000 14 047 250 .15
.0015 1000 .14 .056 250 .15 The amplifiers have
RESISTOR ASSORTMENTS .0018 1000 14 .068 250 .15 mentary class B output. The circuit
Each assortment cOntain, 5 pc each of 10 el...rent values. .0022 1000 14 .082 250 .17 employs flip-chip transistors with RIGHT
Values included are Mown In (Ohms/ .0027 1000 14 1 100 17 high reliability and passivated chip ,xm
XW.5% 050 pegs total). ..51.75 / XWS% (50 pa totall...51.85 0033 1000 .14 12 100 .18 Power transistors with excellent sec- lee
Aast.1 i 10, 12, 15, 18. 22, 27, 33, 39. 47. 56 ohm 0039 630 .14 .15 100 .20 ondary breakdown strength. Built -in IV
Asst.2: 68, 82. 100, 120, 150, 180. 220. 270. 330, 390 ohm 0047 630 .14 .18 100 .21
470. 560. 680.820 ohm, 1K, 1.2K. 1.5K, 1 8K, 2.2K.2.7K .0056 630 .14 22 100 .23 current limiting is provided for SI-
Asst.3: 1050G and all devices can be super
Aast.4: 3.3K, 3.9K. .7K. 5.6K, 6.8K, 8.2K. 10K. 12K, 15K, 18K .0068 630 14 27 100 .26
.0082 630 .14 .33 100 .30 aced from a single or split power
Asst.5: 22K, 27K, 33K, 39K, 7K. 561C. 68K. 82K, 100K, 120K 01 630 .14 39 100 supply.
I lea 1410111
.33
Aast.6: 150K, 180K, 220K, 270K. 330K, 390K,470K.560K,680K, .012 630 .14 .7 100 .36
820K .015 400 .15 .56 100 .44 SI -1010G 110W output) ...5 6.90
Asst.7i /M,1.2M.1.5M,1.13M,2.2M,2. 7M,3.3M,3. 9M.4 7M 5.6M. 018 400 .15 .68 100 .47 SI -1020G 120W output) ... $13.95. o
l'%W Assortment No.7 doesn't include 5.6M) .022 400 .15 82 100 .54 SI -1050G 150W output/ .. $26.80
,

416t.BR:innn sewn assortments woo. .027 400 .15 1.0 100 .60
14W 5', 350 cars lotI 510.95 '.W.5%.350 ocs total $11.55 033 250 15 Data Sheet with Application Notes - $0.50
MAIL ORDER ADDRESS -
P.O. Box 2208P, Culver City, CA 90230. Send check or

ANCRONA money order, COD, Master Charge and BankAmericard welcomed. Minimum Order:
610.00. Add $1.00 to cover postage and handling. California residents add 6% sales tax.
TELEPHONE ORDERS: Call (213) 641 -4064.
ANCRONA STORES DO NOT ACCEPT MAIL OR TELEPHONE ORDERS
CALIFORNIA CALIFORNIA ARIZONA OREGON GEORGIA TEXAS CANADA, B.C.
No. 101ANCRONA ANCRONA ANCRONA ANCRONA ANCRONA ANCRONA ANCRONA
260 pogo 11080 Jefferson Blvd. 1300 E. Edinger Ave. 4518 E. Broadway 1125 N.E. 82nd Ave. 3330 Piedmont Rd., NE 2649 Richmond Vancosvo'
INFORMATION Culver City, CA 90230 Santa Ana, CA 92705 Tucson, AZ 85711 Portland, OR 97220 Atlanta, GA 30305 Houston, TX 77098
BOOKLET (213) 390-3595 (714) 547 -8424
Only 5495 (602)881 -2348 1503) 254 -5541 (404) 261-7100 1713) 529 -3489

CIRCLE NO 4 ON FREE INFORMATION CARD

JULY 1977 113
 S. D. SALES CO. DALOAS TEXAS 705228
JUMBO LED CAR CLOCK %hie ,ffottedt SPA/ Xit
$16.95 KIT we ße2 744 '
Cloak
5ie $e YO ' You requested it! Our first D.C. operatec clock kit. Professionally
engineered from scratch. Not a makeshift kluge as sold by others.

tL
100 Say'
1

Cja
rl i
Features:
A. Bowmar Jumbo .5 inch LED array.
B. MOSTEK - -
50250 Super Clock Chip
ßj0 er5 - C. On board precision crystal time base.

/`} CAS
ALARM OPTION $1.50 D. 12 or 24 hour Real Time Format.
AC XFMR S1.50 - E. Perfect for cars, boats, vans, etc.
F. P.C. Board and all parts (less case) included.

f
1702A 2K EPROM UP YOUR COMPUTER!
28 PIN IC
Sockets
4 3/$1.00
11,000 MFD L02 -1K LOW POWER 500 NS STATIC RAM
We tell it like it is! We could have said these were 21 1
39 MFD
16V Mallory
Coniade factory new, but here is the straight scoop. We Time is of the essence!
Grade
3- $79545 Electrolytic cap -$3. bought a load of new computer gear that contained And so is power. Not only are our RAM's faster
MHZ Time 15 for $1.
Crystal a quantity of 1701 A's in sockets. We carefully than a speeding
p ding bullet but they are now very low
$1.25 removed the parts, verified their quality, and are power. We are pleased to offer prime new 21 L02
offering them on one heck of a deal. First come, -1 low power and super fast RAM's. Allows you to

60HZ Crystal first served. Satisfaction Guaranteed! U. V. Erasea-

ble. (2.3 US access time.) NEW PRICE!
STRETCH your power supply farther and at the
same time keep the wait ght off!
I

Time Base $2.95 each 8 for $12.95

$ 5.9 5 2/$10. $12.95 S. Z. Sale egdzu¿oe/ $12.95
MOS DIGIT UP -DOWN COUNTER 6
FEATURES: 40 PIN DIP. Everything you ever wanted in a counter chip. Features: Direct
TUR output
P with accuracyY comparable
P to a digital
9 LED segment drive, single power supply (12 VDC TYDE), six decades up/down,
watch. pre -loadable counter, separate pre-loadable compare register with compare out-
B. Directly interfaces with all MOS clock chips. put, BCD and seven segment outputs, internal scan oscillator, CMOS compatible,
C. Super low power consumption (1.5MA typ.) leading zero blanking, MHZ. count input frequency. Very limited quantity!
1
D. Uses latest MOS 17 stage divider IC.
E. Elimiates forever the problem of AC line glitches.
F. Perfect for cars, boats, campers, or even for portable
clocks at ham field days.
IC's from XEROX
7400 -- '1c 7430 -- 9c9c 7493 --26c 1402A -Shift Reeggulator -50c
G. Small size; can be used in existing enclosures. 7402 ',c 7440 74121 - 55o
Kit includes Crystal, Driver IC, PC board, plus all necessary 7404-
- 11c 9c 7437 - 10c 74123 -- 22c
32c
MH0025CN

parts and specs. At last count over 20,000 SOIL! - 7406

7407 - 11c
7410 - 9c
7438 - 10c
7451 - 9c
7474 - 16e
74151 22e
74155 - 22c
74193 - 35c
IC'S REMOVED FROM
PC BOARDS
ALL TESTED:
7475 - 24c
S.D. Sales Exclusive! 7420 -19c 7486 - 16c 8nte3- 1302 -45c
FULL SPEC.

p
o
Ir
Rated
1000 MFD
Filter Caps
35 WVDC up-
SLIDE SWITCH
Assortment
Our best seller. Includes
POWER
RESISTOR
RESISTOR
ASSORTMENT P.C.LEAD
DIODES
Transistor Grab
gag no 1
DISC CAP
ASSORTMENT
.lust received a good, PC leads. At least
right style with PC miniature and standard 15 OHM %W 5% & 10%. PC
1N4148/1N914 different

.
9
leads. A good mix of mixed lot of National 10 val-
leads. Most popular val- sizes; single and multi- 25W 100/$2.00 To92 plastic transis- ues. Includes:
ue for hobbyists. Corn- position units. All new, values.
íN 4002 1 A al
fa1
BY tors. PNP & NPN, even .001, .01, cc
pare at to Si ee- narne brand. Try 100 PIV other star-
a few FET's. 40 to 50% plus
from franchise type e- pre package and you'll
one CLAROSTAT Yield. Untested. Asst. dard values.
lectronic parts stores. reorder more! Special!

4/$1.00 12/$1.00 750:P ea. 200/$2. 40/$1. 500/$3. 60/$1.00

DIGIT ALARM CLOCK KIT
$9.9 5 KIT
P.C. Board -$3.00
TASTIC KIT EVEN BETTER. REDESIGNED TO TAKE ADVANTAGE OF THE
WE MADE A FANTASTIC
LATEST ADVANCES IN I.C. CLOCK TECHNOLOGY. FEATURES: LITRONIX DUAL %z" DIS
AC XFMR -$1.50 PLAYS, MOSTEK 50250 SUPER CLOCK CHIP, SINGLE I.C. SEGMENT DRIVER, SCR DIGIT
Do not confuse with Non -Alarm DRIVERS. GREATLY SIMPLIFIED CONSTRUCTION. MORE RELIABLE AND EASIER TO
kits sold by our competition! BUILD. KIT INCLUDES ALL NECESSARY PARTS (except case). P.C.B. OR XFMR OPTIONAL.
Eliminate the hassle - NEW! WITH JUMBO LED READOUTS!
avoid the 5314!
MOTOROLA SCR
/ COMPUTER POWER SUPPLY
P.C. Leads.
2N4443. 8 AMP 400 PI V.
$31$1.00 64I A tortunate
very of industrial quality
purchase. One the best REG-
FAIRCHILD - TBA 641
4W. Audio power
P Amp.p. Just
out! In special heat sink DIP.
N
vv
\
tU/L/
1 2
ULATED
Input
-SVDC
is
@SOOMA;
supplieswe
120VAC
have
60HZ.
seen.
Has
-15VDC @1.25AMP;
the
Hig, performance, small size.
following regulated
-25VDC @180MÁ.
a fraction of original cost. Do yourself a favor and order NOW.
outputs:
Sold at

One super audio IC.

$1.50 with data ' AMD - 1702Á
AC LINE FILTER
Rated 3 AMPS - 115/230V N.-4, e1í Factory Prime Units - Brand New - 1.5 Micro-seconds Access Time. $4.95 each -
10 FOR $40. HUGE FACTORY DIRECT PURCHASE!
50 to 400 HZ.
Noise Proof Your Computer your Bankamericard or CHEAP DC SUPPLY
$3.00 each TERMS: Master Charge order in on our
continental United States toll
Actually an Ac dapter for alculators.
9V DC -no load. 6VDC @200MÁ.
GRAB BAG NUMBER 2 MONEY BACK GUARANTEE. ' 4VDC @375MA
Mixed Motorola TO -18 case met- free Watts:
NO COD's. TEXAS RESIDENTS
$2. ea.
1- 800 -527 -3460
al transistors. About 60% yield. ADD 5% SALES TAX. ADD
PNP & NPN. Untested. A good 5% OF ORDER FOR POSTAGE
assortment! 100 for $3.00 HANDLING. ORDERS S.D. SALES CO.
& Texas Residents Call Collect:
PRICES SHOWN SUBJECT UNDER $10.00 ADD 75c. P.O. BOX 28810 -D
TO CHANGE WITHOUT
NOTICE. 214/271-0022 FOREIGN ORDERS: U. S.
FUNDS ONLY!
DALLAS, TEXAS 75228

Orders over $15. - Choose $1. FREE MERCHANDISE! CIRCLE NO. 44 ON FREE INFORMATION CARO
114 POPULAR ELECTRONICS
 Popular Electronics T(MPUTER
JULY 1977
PRu
EVK Y9
ADVERTISERS INDEX
$133.00
READER
SERVICE NO. ADVERTISER PAGE NO.
* SPECIALITY CHIPS *
121

7500
15 (10

1 A P Products, Inc 7
2 Active Electronic Sales Corp 99 * CRYSTALS A,
3 Advanced Microcomputer Products 115 Fr

*
* NEW CTS DIPSWITCHES *
4
6
Ancrona Corp
Avanti Research & Development, Inc
113
0971
6800 96460

1100 90800
MICROPROCESSOR PRODUCTS
* DIVIDERS *
1

15041

7 B &K Precision, Dynascan Corp 61

15
6.1
8 Bullet Electronics 100 11 4. 10.0

o 444.44, 2.0 6305

224 79.
2906
CREI Capitol Radio Engineering '9 C4.3
43.1.1,
90140 004 8224
8008 $224
4
1495
:
Institute
BOBO 170751
28, 29, 30, 31 Mil., 1
73141 170. ir

Cleveland Institute of
Electronics Inc 18, 19, 20, 21
l6 90.19
* SPECIALS *
9 Cobra, Product of
Dynascan SECOND COVER
* SPECIAL * * S100 COMPATIBLE PRODUCTS * * CHAR GEN /ENCODERS * * CONNECTORS *
10 Continental Specialties Corp 39
LPRIIIN

11 Digi -Key Corporation 101 It V1

12 Digital Group, The 13 -. MOTOROLA * * LOGOS 4. AS MISCELLANEOUS * * DATA BOOKS *
13 EICO 96
14 Edlie Electronics 102 9602 16 Vol C.N. 7700
2610
15 Edmund Scientific Co 116
1/500 *SHIFT REGISTERS
16 Eltron 106 275011
17 Empire Scientific Corp 57 5.
FUNCTION GEN KIT
Extron LIFESCREEN Projection 019$1.1090. 99
18
System 83 *=,., 19 MONI7ORS
: n'":"
PRItuf

* 540

19 Godbout Electronics, Bill 100 I C MARKET PLACE

20 Grantham College of Engineering 96 LINEAR LINEAR * * 741500 TTL
UARTS
21 Greenlee Tool Co 81
* DISPLAYS/LEDS

22 Handic U.S.A. Inc 37 05 1,3408 15 , Lk4,46N 19

5 Heath Company , ... ......62, 63, 64, 65 0420,1. 45 .111/09 ii81406H 95 RC11951. 695
10p 1.5107. 1.4821t.
*
L5420031 95 FIC1458C44 89

*
1

15147 n

23 Illinois Audio 75 'LZI1F.1 I ri

CONTINENTAL SPECIALTIES TRANSISTORS

24 International Electronics Unlimited 98 L5153

11°1

t:1 1,1566[19 1,

* *
2

74LSDSTTL
JBL 5 L.4
0.43.19.4
195
195
1,658
Lmro
115

25 James Electronics 110, 111 L43209 5

0.4.1204, PI
1

195
Y.

28 Midland International 2
L 71

32 MITS 27
29 Motorola 71
Motorola Semiconductor Products Inc 91
26 McIntosh Laboratory Inc 83 P. O. BOX 17329
27 McKay Dymek Co 16 Irvine, California 92713
New Phone (714) 558-8813
NRI Schools 8, 9, 10, 11
30 National Camera 75
31 New -Tone Electronics 103 CIRCLE NO. 3 ON FREE INFORMATION CARD

33 OK Machine & Tool Corporation 35

34 Olson Electronics 102
35 Optoelectronics 112

36 PAIA Electronics 94
37
38
Pace CB
Pickering & Company
FOURTH COVER
THIRD COVER
ABOUT YOUR SUBSCRIPTION
39 Poly Paks 109
Your subscription to POPULAR ELECTRONICS is maintained on one of the world's most modern, effi-
40 Quest Electronics 104 cient computer systems, and it you're like 995' of our subscribers, you'll never have any reason to
complain about your subscription service.
41 Radio Hut 105
We have found that when complaints do arise, the majority of them occur because people have writ-
Radio Shack 23
ten their names or addresses differently at different times. For example, if your subscription were listed
42 Ramsey Electronics 97 under "William Jones, Cedar Lane, Middletown, Arizona," and you were to renew it as "Bill Jones, Ce-
43
dar Lane, Middletown, Arizona," our computer would think that two separate subscriptions were in-
S.A.E. 95
volved, and it would start sending you two copies of POPULAR ELECTRONICS each month. Other exam-
44 S. D. Sales Co 114
ples of combinations of names that would confuse the computer would include: John Henry Smith and
45 Sabtronics International Inc 17
46 Henry Smith; and Mrs. Joseph Jones and Mary Jones. Minor differences in addresses can also lead to
Sencore 25
difficulties. For example, to the computer, 100 Second St. is not the same as 100 2nd St.
47 Solid State Sales 106
So, please, when you write us about your subscription, be sure to enclose the mailing label from the
48 Southwest Technical Products Corp 40 cover of the magazine-or else copy your name and address exactly as they appear on the mailing
Speakerlab, Inc 90 label. This will greatly reduce any chance of error, and we will be able to service your request much
Superscope, Inc 14, 15 more quickly.
CLASSIFIED ADVERTISING
97, 98, 100, 102, 106, 112
JULY 1977 115
 THERE IS NO OTHER TELESCOPE LIKE IT!
MAZING HARD -TO -FIND
SCIE CE BUYS! THE NEW EDMUND 41/4; f/4
ALTER ATE ENERGY NEWTONIAN WIDE FIELD
SPACE A GE HOBBIES REFLECTOR TELESCOPE
Clear, bright, spectacular wide angle views of
SUPER POWER FOR ANY AM RADIO
Antenna assist has pulled in stars, moon, comets ... easy to use ... portable!
stations up to 1000 miles' off!
No wires, clips, grounding. Solid IN SECONDS.YOU'RE SCANNII4G THE ASTOUNDING UNIVERSE, able to
see and study the breath-taking cosmos as perhaps you never have before
state - no elec.. batts., tubes. .. awesome vastness. unbelievable orderliness. stark silent beauty All the
No. 72,095AV $19.95 Ppd. fascinating heavenly mysteries are yours to enter and explore. This new
ULTRA SELECT -A-TENNA reflector telescope makes it easy for everyone to span a thousand fight -years to
(OVER 1000* MILES) space -age enjoyment of the heaver sand outdoors. No complicated set up, Just
$24.95 insert the eyepiece. focus. and its big 31/2' field of view gives you more stars in a
No. 72,147AV single view than any other type of telescope. Bright. crisp finely resolved images
SUBJ. TO LOCAL COND. to capture your interest and imagination its probably the easiest to use telescope
ever over your shoulder. in your lap on a tripod. Or just otate the spherical base
SAVE 50%1 8 x 20 MONOCULAR on its own mount for use on a table. car hood Take it anywhere (only 17. 101b I
Top quality Optical system. 41/4-. f/4 parabolic primary mirror (Y wave. 17' F L.1
Top quality Spy Scope, a S30 prealigned Vs wave diagonal on a coaled optical window seals optics from moisture
value, now $14.95! Special pur- and dust; 28mm Kellner eyepiece (gives 150, higher without other eyepiece or
Barlow). Fast focusing (25' to infinity). Bright Scharfanian red (doesn t impair night
chase saves you 50% 100% vision): adi carrying strap A 'first scope must
coated optics; 393 ft. field of Patent
view. Only 2 oz.-
stores in Pending an ideal second scope'
There Is no other telescope like N. NO. 2001 A V
$149 pp d. 95
pocket, purse, glove box.
No.1568 AV .. $14.95 Ppd.
GIANT MAGNET, LITTLE PRICE!
Tie a line to our over-150 lb. -lift The Edmund BIOSONE II
ceramic magnet and haul up turns brainwaves into an audible or visual signal. $149.95
treasure from the sea. 4 ceramic
magnets, in series, between
steel plates. A 1 -lb. "giant "! KNOW YOUR ALPHA FROM YOUR THETA!
For greater relaxation, concentration ...
No. 42.318AV (1 x 11/4 x 434) $11.95 Ppd.
monitor your alpha /theta brainwaves.
NASA -CHOSEN FOR APOLLO /SOYUZ Features Normally Found Only In Units Selling For
this super
The Astronauts used
20X60 binocular (modified) to
More Than $200.00-And 3 Feedback Modes.
view Earth! Big 60 mm objective The portable, professional qualit" Edmund Biosone Il boasts 3 feedback
lenses; 173 -ft. field of view at modes -LED FM tone, threshold tone; a test mode to check overall
1000 yds. Relative brightness, system of operation. Easy to tse. this beautiful 4- pound, simulated
9.0. Fully coated optics, more! walnut unit (91/2 x 5% x 4% ") can be operated at home, in office or clinic. It
gives you outputs to allow further monitoring of logic signal, raw EEG,
No. 1556AV (9V4x81/ "; 47.5 or) $99.95 Ppd. fitter output, meter, and FM. Total brainwave monitoring capability, incl.
filter select feedback, with wide range calibration sensitivity control
(5-100 microvolts). Completely safe. the Edmund Biosone Il is similar to
MEASURE WIND SPEED ANYWHERE an electroencephalograph (EEC*. enabling you to identity the electro-
Hold handy (16 oz. 1 low cost chemical activity that exists at all times in the human brain. In addition to
Anemometer into the wind, letting you know when you're most relaxed, Biosone Il is a great
quickly read wind speed on its conversation piece. Included at its low price are a set of electrodes. an
big dial-from 5 to 70mph. Acc. earphone jack for private use. Uses latest advances in linear circuitry,
to -_3 % of full scale (2.1 mph); runs on two 9v transistor batterias (not included).
no batts., adjustments, recali-
bration req.! (7y" HIGH) STOCK NO. 1668AV Just 5149.95 ppd.
No. 42,426AV $19.95 Ppd. LOW COST STARTERS' UNIT, No. 71,809AV $59.95 ppd.
WORLD'S LARGEST SOLAR CELL...

if 2 the most powerful silicon,

cheapest dollar per watt! 4" ilia.
giant can put out 1 full watt,
"SEE" MUSIC IN PULSATING COLOR
I
No. 42,314AV..(TAB LEADS):
over 2 amps of current at .45v.
Rated 100mW/Gina light intense.
at.45v.
$29.95 Ppd.
4% \l,))ix))4 /r The Edmund
3- Channel Color Organ
á 1
50

No. 42,270AV...(1 AMP V W 3" DIA.) $17.95 Ppd. COMPLETELY ASSEMBLED! LESS THAN
DELUX HI -TEMP HALF THE PRICE OF OTHER MODELS!
SOLAR FURNACE
Oversized Fresnel lens enables Create your owl audio "light show ", add a new
unit you screw together to attain
temperatures over 2000F at dimension to your music listening pleasure with
prime focus! Use to temper small the bargain -priced Edmund 3- Channel Sound To
parts; fire enamel on jewelry, Light Control. Lets you modulate 3 independent strings of
more! 6 parts easily assembled
w /instrs.
colored lamps with the intensity of your music. They flash and
ASSEMBLED
vary in brightness related to the music's rhythm, pitch and
No. 80257AV(81/2 lb. 34" hl)
ELECTRONIC COUNT-DOWN
$59.95 Ppd
NO. 42,309AV $18" Ppd. volume -a
pulsating light performance to music! You get
STOPWATCH volume and frequency sensitivity to a peak rating of 300 watts
FORM
Hand -held 5 -oz digital stop-
UNASSEMBLED, IN KIT per channel. Just plug in yoJr favorite colored flood or spot-
watch counts up, down, sounds s1595 light. and turn on! Great price, too. This high quality, fully
alarm -w
/full range LED display
No.42,336AV ONLY Ppd. assembled unit in metal housing, with 3 individually controlled
(9 hrs., 59 mins., 59 secs.) Has
start/stop (time -out) /reset but- circuits, is priced at less than half that of others. Complete
tons. Accurate alarm clock! 3 AA instructions are included with this terrific value.
No. 1692AV (2.8 x 4.3 xb1 15j $49.95 Ppd.
ELECTRONIC SOUND COLLECTOR COMPLETE AND MAIL COUPON NOW
Tune in whisper at 20 ft., nor-
EDMUND SCIENTIFIC CO. 300 Edscorp Bldg., Barrington, N. 1. 06007
a
mal conversations up to 100 ft..
birdcalls & high freq. sounds a- emSend me the fo low: I
almost 200 ft. Nearly twice as u. r Stock No. Quantity Price Ea.
far over water! Check on baby I
birds! 18" refl. disc. mike, etc.
-SEND FREE I
No. 80,176AV $32.25 Ppd.
t64 PG. CATALOG "AV"
QUALITY DETECTOR UNDER $40 Charge my = American Exp I
Ourfully transistorized BFO unit BankAmericard 11 Master Chg. I
can locate a quarter at 18". Add handling charge $ 1.00
Powerful trans.- oscillator- 40J0 UNL.SUAL BARGAINS Interbank No.
6
Enclosed is _check,
amplifier circuit. Comp. to FOR HOBBYISTS I Card No _M.O. in amount of $
others priced 50% more! Alumi-
num, just 2 lb. SCHOOLS. INDUSTRY I
No.130,222AV $39.95 Ppd. Expiration Date Signature
1 30 -DAY MONEY -BACK SUAK-

- --s- J
Address
EDMUND SCIENTIFIC CO.
- -
IANTEE. You must be satis-

-s -
I
fied or return any purchase
300 Edscorp Bldg.. Barrington, N.J 08007 (609) 547 -3488 30 days for full refund. City, State, Zip
America's Greatest Science Optics Hobby Center In eel MID M
CIRCLE NO. 15 ON FREE INFORMATION CARD
116 POPULAR ELECTRONICS
 The source
of perfection in
stereo sound...
Pickering's new
XS../ 000

The reviewers applaud as never before!

" .. we don't see how you can do better at any price." permits extremely low mass, and also offers high output.
Hirsch -Houck Laboratories. Stereo Review. February 1977 Second, this cartridge features the new Stereohedronh"
"The new unit offers the stereo performance of the XUV/ stylus tip, a Pickering first! This extraordinary shape has a
45000 (or perhaps a little better than that) at a lower far larger bearing radius, which provides increased con-
price. It seems hard to go wrong with such a combina- tact area in the record groove. This assures gentler treat-
tion." ment of the record groove, longer record life, and also,
CBS Technology Center. High Fidelity. February 1977 far longer stylus life.
This cartridge provides remarkably smooth and flat fre-
"Congratulations to all concerned on a fine contender quency response; its channel separation is exceptional,
amongst the world's best stereo pick- ups." its transient response possesses superb definition.
John Borwick. Gramophone. United Kingdom 1977
Truly, Pickering's XSV /3000 represents a whole new
Pickering's new XSV/3000 is a remarkable develop- concept of excellence in stereo cartridges ... the true
ment. It possesses a totally new and different design that Source of perfection in stereo sound.
makes it the precursor of a whole new generation of so- For further information write to
phisticated, advanced stereo cartridges. Pickering & Co., Inc. Dept. PE,
This has been made possible by technological advances 101 Sunnyside Blvd., Plainview, PICKERING
in two areas. First, it has an unusually tiny, samarium New York 11803
'for those who can Car the difference'
cobalt (rare earth) magnet of remarkably high power that PICKERING & CO., INC., COPYRIGHT 1977
CIRCLE NO. 38 ON FREE INFORMATION CARD
 ` 3

hen you've got a Pace [B radio,

There are millions out there with their ears on there clearer and with less distortion, and the
waiting to talk to you Pace to Pace. other guy's voice coming back just as clear.
And with a Pace CB two -way radio you've got To learn more, drop into a Pace place near you.
every bit of power the law allows. And features The dealer will tell you just how economical
to cut through interference and "bleeders and easy -to- install a Pace is. He'll help you
from other channels. choose the one that's just right for you, too.
What's more it's assembled Ask him for the world by the ears. He'll know
with computerized circuitry which CB you're talking about.
PACE CB 8015
and it's 100° solid state,
so it's as trouble -free as
a CB can be.
It all adds up to your 11
BY
ace
PACE CB/ PACE TWO -WAY RADIO PRODUCTS

PATHCOM INC., HARBOR CITY CA 90710

voice getting out 1*144
CIRCLE NO. 37 ON FREE INFORMATION CARE