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KARNAUGH MAPS FOR FAST DIGITAL DESIGN

A neat, simple method for working with logic

HOW TO GET EXTRA FUNCTIONS FOR SIMPLE HAND CALCULATORS

Add memory, constant,% at little cost

BUILD A DIRECT- READING LOGIC PROBE

Readout displays high, low. open and pulse

,'TESTI PORTS:
Heathkit "Digital" Color TV Realistic Portable Scanner
Pickering Discrete 4- Channel Cartridge
Crown Electronic Crossover Hickock Curve Tracer

Whal Does Your Stereo Receiver Dollar Buy?

Hirsch -Houck Labs compares performance and cost

MUM . , .
.. 7' \\*.
..wr.Aw.

www.americanradiohistory.com
 Pioneer's new 9191...the best
cassette deck under 45O
that money can buy.
I-ere is a magnificent cassette deck control, stackable deck to have all the
s ith specifications that are beyond what features we've mentioned.
our industry had been aware were But of all the ingredients that make
possible: specs that surpass anything that up the 9191: performance, reliability, style
a deck of this price, performance and and features, the most important of all is
q.ality has ever been able to come up to its value. We set out to build a cassette
before. Unbelievably low wow and flutter; deck that was better, but less costly, than
sDlenoid cortrols that operate at a touch Unique, effortless front -loading system. any deck built previously. We know we
with almost magical precisioi, and a have succeeded. We lrow that you'll
tcnique, truly -visible horizontal front agree when you see nd handle the
Wading system by which the cassette is Pioneer CT-F9191 your Pioneer dealer.
effortlessly set into place with two fingers,
ae only a few highlights. CT-F9191 Spec Ícations:
Pioneer s new 9191 incorporates a Frequency Re ponce: Standard, LH tape: 25-
16,000 Hz (35- 13,000 Hz ±3dB); CrOz tape:
cascade of features and innovations: 20- 17,000 Hz (30- 14,000 Hz ±3dB)
automatic Cr02 tape detector and indicator SignaltÓ -Noise Ratio: Dolby OFF: More than
light; an illuminated panel scale that lets Selectable equalization and bias switches.
52, dB; Dolby ON: More than 62 dB (Over
y3u see at a glance the amourt of tape 000 Hz, Standard and LH tapes) More than
optimized for any kind of cassettes you /66.5 dB over 5.000 Hz with CrOz tape
remaining or a cassette; and an advanced want to use. And, of course, there's built- /Harmonic Distortion: No more than 1.7% (OdB)
memory rewind circuit that pe-mits quick in Dolby B' to bring the 9191's S/N ratio
aid easy location of (and automatic re- Wow and Flutter: No more thas 0.07% (WRMS)
up to 62 dB, even with standard tapes
s-art from) any point on a cassette We've also included separate line U.S. Pioneer Electronics Corp.,
tope. It also has two independant drive mixing, and an extra pair of input and 75 Oxford Drive, Moonachie,
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that the 9191's recording capability is
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And it's the only front -loading, front-
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CIRCLE N0. 66 ON FREE INFORMATION CARO

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CIRCLE NO 46 ON FREE INFORMATION CARD

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 NEW. .. from A P Products

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CIRCLE NO. 2 ON FREE INFORMATION CARO
2 POPULAR ELECTRONICS

www.americanradiohistory.com
 SEPTEMBER 1975 VOLUME 8, NUMBER 3

Popular Electronics (

WORLDS LARGEST SELLING ELECTRONICS MAGAZINE

FEATURE ARTICLES
WHAT DOES YOUR STEREO RECEIVER DOLLAR BUY/ Julian D. Hirsch 33
Hirsch -Houck Labs compares performance and price
KARNAUGH MAPS FOR FAST DIGITAL DESIGN Art Davis 50
A neat. simple method for working with logic
ENGLISH- LANGUAGE SHORTWAVE BROADCASTS FOR SEPT. & OCT. 1975 Richard E. Wood 82

CONSTRUCTION ARTICLES
HOW TO ADD FUNCTIONS TO SIMPLE HAND CALCULATORS Donald Shapiro 38
If it contains the right IC. your calculator can be made more useful
BUILD A HIGH -PERFORMANCE CD-4 DEMODULATOR Louis Dorren 39
Low -cost demodulator for playing discrete 4- channel discs.
BUILD A DIRECT -READING LOGIC PROBE R M. Stitt 54
Seven- segment readout displays high. low, open. and pulse.
SKIN TEMPERATURE THERMOMETER C. Shakespeare 62
Consciously controlling blood flow is said to improve body functions.

COLUMNS
STEREO SCENE Ralph Hodges 22
Starting With a Lacquer Disc.
COMPUTER BITS Jerry Ogdin 57
Hobbyist Interchange Tape System.
TEST EQUIPMENT SCENE Leslie Solomon 79
Checking the Sweep Generator "Birdie.'
DX LISTENING Glenn Hauser 80
Antarctica Calling.
SOLID STATE Lou Garner 84
New IC's for Digital Watches.
HOBBY SCENE Editorial Staff 91

PRODUCT TEST REPORTS

PICKERING MODEL XUV/45000 CD -4 PHONO CARTRIDGE 68
CROWN MODEL VFX2 ELECTRONIC STEREO CROSSOVER SYSTEM 69
HEATHKIT MODEL GR-400 "DIGITAL" COLOR TV RECEIVER KIT 71
REALISTIC MODEL PRO -6 PORTABLE SCANNING RECEIVER 72
HICKOCK MODEL 440 TRANSISTOR CURVE TRACER 78

DEPARTMENTS
EDITORIAL Art Salsberg 4
About Editorial Bull Sessions.
LETTERS 6
OUT OF TUNE 6
Build a Muscle Feedback Monitor (May 1975)
NEW PRODUCTS 12
NEW LITERATURE 16
NEWS HIGHLIGHTS 26
TIPS & TECHNIQUES 90
ELECTRONICS LIBRARY 92
OPERATION ASSIST 94
COVER PHOTO Photographed at
Grand Central Radio. New York City
POPULAR ELECTRONICS. September 1975. Volume 8. Number 3 Pub- Ziff -Davis also publishes Boating. Car and Driver Cycle. Flying. Modern
lished monthly at One Park Avenue. New York. NY 10016 One year sub- Bride. Popular Photography. Skiing and Stereo Review
scription rate for U S 56 98. U.S Possessions and Canada. 57 98. all
. Editorial correspondence: POPULAR ELECTRONICS. I Park Ave.. New
other countries. 58.98 Second Class postage paid at New York. NY and at York NY 10016 Editorial contributions must be accompanied by return
additional mailing offices Authorized as second class mail by the Post postage and will be handled with reasonable care. however. publisher
Office Department. Ottawa. Canada and for payment of postage in cash. assumes no responsibility for return or safety of manuscripts. art work. or
Subscription service and Forms 3579. P O. Box 2774. Boulder. CO 80302 models
POPULAR ELECTRONICS including ELECTRONICS WORLD. Trade Forms 3579 and all subscription correspondence: POPULAR ELEC-
Mark Registered Indexed in the Reader s Guide to Periodical Literature TRONICS Circulation Dept P 0 Box 2774 Boulder. CO 80302 Please
COPYRIGHT 1975 BY ZIFF -DAVIS PUBLISHING COMPANY ALL allow at least eight weeks for change of address. Include your old address.
RIGHTS RESERVED enclosing if possible. an address label from a recent issue

SEPTEMBER 1975 3

www.americanradiohistory.com
 Popular Electronics®
EDGAR W. HOPPER
Publisher

ARTHUR P. SALSBERG
Editorial Director

LESLIE SOLOMON
Technical Editor
Editorial
JOHN R. RIGGS
Nannging Fritter

ALEXANDER W. BURAWA
A.,,ociate Editor

EDWARD I. BUXBAUM ABOUT EDITORIAL BULL SESSIONS

Art urrcctor

JOHN McVEIGH
A.,.n,rnnt Editor The editors here at POPULAR ELECTRONICS get together on a regular and
ANDRE DUZANT irregular basis to ruminate about the state of the art, where it's headed,
rechrcal Illustraler and sundry editorial problems and challenges. Here's a minuscule
sampling of what we typically discuss at these bull sessions.
HERBERT S. BRIER
LEN BUCKWALTER Why do two audio amplifiers with identical performance specifications
LOU GARNER sometimes sound different? One consideration, we concluded, may be
GLENN HAUSER
JULIAN D. HIRSCH "transient intermodulation distortion" or TIM. Essentially, this concerns
RALPH HODGES the delay that occurs between a transient input signal to an amplifier and
ART MARGOLIS
WILFRED M. SCHERER its output signal. Because of the delay, there is no feedback to modify the
Contributing Editors
momentary high input as occurs under steady -state conditions. The upshot
JOSEPH E. HALLORAN is often some degree of overload clipping, compounded by an extension of
Ad,ern,ing Uinertnr cut -off time by the feedback mechanism. Such a short burst of
JOHN J. CORTON intermodulation distortion is said to resemble momentary crossover
Ad, erl,o,,,e Sale,
distortion in solid -state amplifiers, which is revealed as a harshness
LINDA BLUM of sound.
-1d, erti.,in4 llnnager
Su r , , , ,
Unfortunately, TIM is undetectable at the output. To measure it requires
PEGI McENEANEY disconnecting the feedback loops, a job that's easier said than done.
F. rectal, .l urstnrit
Conclusive tests on this elusive distortion mechanism have not been made,
STANLEY NEUFELD to our knowledge. So you can be sure that we'll be kicking this one
,Sonnte Publisher
around again.
FURMAN H. HEBB We naturally follow electronic developments very closely, keeping each
ero,rp t r. Electronic, tr Phon,
other posted on what we learn. For instance, moderately priced erasable
ZIFF -DAVIS PUBLISHING COMPANY
Popular Electronics
PROM's for hobbyists do not appear to be too far down the road. Also of
Editorial and Executive Offices interest, fusable -link PROM's (see our July 1975 issue), which in effect
One Park Avenue New York, New York 10016
212- 725 -3500
allow you to make your own ROM's, are obviously untested by the
Hershel B Sarbm, President manufacturer in final form. As a result, some 2% are likely to be defective.
Furman Hebb, Executive Vice President
Vincent Perry. Financial Vice President and Treasurer So add an extra device or two to your order to cover this possibility.
Phillip T Heffernan, Senior Vice President, Marketing
Edward D. Muhlfeld, Senior Vice President.Sports Division
Our readers are a major subject of discussion, too. What do you want to
Philip Sine, Senior Vice President hear about: microprocessors, shortwave listening, hi -fi? Your letters help
Frank Pomerantz. Vice President. Creative Services
Arthur W Butzow. Vice President. Production us answer this question and you'll sometimes see editorial changes
Lawrence Sporn, Vice President. Circulation reflecting them. For example, it's clear that our recently introduced
George Morrissey. Vice President
Sydney H Rogers, Vice President quarterly column, "Computer Bits," will be increased in frequency due to
Sidney Holtz, Vice President its enormously favorable response and the many requests for more
Charles B Seton. Secretary
Edgar W Hopper. Vice President, Electronics Div coverage. Also, we'll be resurrecting "Operation Assist" for readers who
William Ziff. Chairman can't locate the schematics or parts for an old product. Other pleasant
W Bradford Briggs, Vice Chairman
surprises are in store for you, too.
Midwestern Office And, of course, we chat about problems with some reader mail. So there
The Paths Group, 4761 West Touhy Ave
Illinois 60644, 312 679 -1100
are a few requests we'd like to make of you. They concern letters that you
GERALD E WOLFE. THOMAS HOCKNEY hope to have answered. To help ensure a reply, please enclose a stamped,
Western Office
9025 Wilshire Boulevard. Beverly Hills, CA 90211
self- addressed envelope. Due to the tremendous volume of mail received,
213 273 -8050, BRadshaw 2 -1161 we can't respond if this is not done. Furthermore, we simply cannot modify
Western Advertising Manager, BUD DEAN
or troubleshoot circuits by mail, as much as we'd like to. To answer
Japan James Yagi
Oli Palace Aoyama. 6 -25. Minami Aoyama
complicated design questions would jeopardize our schedule, which must
6Chome, Minato -Ku. Tokyo 407- 1930/6821, be met monthly to satisfy all of our nearly 400,000 readers.
582 -2851

C 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 disclosed in this issue

4 POPULAR ELECTRONICS

www.americanradiohistory.com
 no strings
attached
NEW %Veller°coRDLEss SOLDERING IRON
GOES ANYWHERE

A professional quality tool, Weller's feather -light and

fingertip -handy WC -100 Cordless Soldering Iron allows
you to make connections anywhere...without
dependence on an AC cord and outlet.
The heart of the WC -100 is its high- energy,
long -life, nickel- cadmium battery which springs
into action at the touch of your finger, heating
the tip to over 700 °F in just 6 seconds.
And no danger of accidental discharge.
Weller's exclusive sliding safety switch
breaks the circuit when your finger is
removed, won't lock in "on" position, and
does lock in "off" position for added
safety while restoring energy with fast -
power recharger (UL listed).
Loosen two slotted set screws and
you've got instant choice of four tips...
regular, long- reach, fine -point, or miniature
...each mounted on an extra -strong
stainless tube to resist bending. Tip is
continuously illuminated by the built -in light
which focuses on the work area, a special
advantage under poor lighting conditions.
Try this for size! It's a full -scale photo of the
compact WC-100. And the real thing is waiting
for you at your dealer or distributor...right now.
Need to know more? Request literature.

Weller -Xcelite Electronics Division

COOPER The Cooper Group
INDUSTRIES
P. O. BOX 728, APEX, NORTI- CAROLINA 27502
CIRCLE NO. 61 ON FREE INFORMATION CARD
SEPTEMBER 1975 5

www.americanradiohistory.com
 CREDIT FOR CONVERTER CIRCUIT

was pleased to see a good application

Aee Nete I

for a V -to -f converter in the article "Conver-

ter Turns Counter into a Digital VOM" (May
PROBE IV 1975). However, was disappointed to see
I

that a reference was not given for the

CAT.NO. source of this circuit. developed the cir-
I

5104

Letters available. -
cuit shortly after the NE 555 timer became
H. Klement, White Plains, N.Y.

The author included the reference in his

manuscript. It was dropped in editing.
BITS ON COMPUTER BITS RED IS OK

The response to Jerry Ogdin's first Com- In the article Build a Digital Marine /Auto
puter Bits column (in the June issue) has Tachometer" (June 1975), it was stated that
CHECK FOUR FUNCTIONS
been tremendous. Here are excerpts from the use of red displays for anything other
WITH ONE INSTRUMENT ! just a few of the letters: than emergency indicators in automobiles
., Continuity Polarity is illegal.
Voltage ,, Digital Logic Thanks for your new column. am in- I We checked this out with the National
terested in being a member of a computer Highway Transportation Safety Administ-
-
LIGHTWEIGHT POCKET SIZE hobbyist group. -John F. Sprague, Allen- ration, which is responsible for Federal
PROTECTIVE. VINYL C.IRRYIN dale, N.J. ... Make it monthly instead of Standard 101 (covering the subject), and
POUCH. SEE YOUR FAVORITE quarterly as soon as possible. am a I also with the Motor Vehicles Manufactur-
ELECTRONICS DISTRIBUTOR. reasonably good programmer but need
support in electronics. -
Peter Nevius,
Niskayuna, N. Y... Because of this, have I
ers Association in Detroit, which provides
automobile industry standards. We find no
basis for the prohibition mentioned. -
just subscribed to your magazine. -Howe David K. Bradley,E. F. Johnson Co.,

6o4°1Ti
C. Fong, Los Angeles, Calif.... have years I Waseca, Minn.
of experience with hardware, but none with
Thanks for bringing us up to date. Our
software. Please continue the column. -J.
statement was based on information we
E. Kircher, Hannibal, Mo.... would like to I

received several years ago when the

see this column become regular, instead of
NHTSA was with the Department of Com-
in touch with 1975. -
a quarterly thing. Glad to see somebody's
R. M. Bash, Fair-
banks, Alaska.... We found your new col-
merce.

THE LONG CONNECTION

umn very interesting. We will be using your
In your July 1975 editorial (The ATIS
magazine as a "textbook" starting next fall.
The wide variety of articles, new compo- Connection), you said that transmission of
nents, career opportunities, basic design the identifying code would take about 1/4
projects, quizzes, printed and digital cir- to 1/5 of a second. Using the most common
The All -New, CAT. NO. implementation of the ASCII code, includ-
Quick And Easy
Way To Reproduce
J4-828
Mo . . .
-
cuit projects all fit into our introductory
electronics course. J. W. Craig, St. Louis,
welcome the appearance of
. I
ing framing bits for synchronization, a total
of ten or eleven bits is required per charac-
Printed Circuits. "Computer Bits." However, resent your I
ter. Thus a 22- character message (sug-
gested for ATIS) means the transmission of
Get Your Kit From statement that there are those who know
hardware but nothing of programming and 220 or 242 bits. At 100 bits per second, each
Your Favorite ATIS would take just under 21/2 seconds.
CALECTRO Electronics those who know software but not hard-
Even more discouraging (about ATIS) is
ware. know both very well and fully believe
Distributor Today !
I

that the suggested frequency is smack -dab

that you can't understand all implications
of either without knowing both. - in the middle of the speech band. Of

,
H. J.
Kuhman, Pittsburgh, Pa.... am guessing course, that's where you want it for use
I

GC ELECTRONICS with equipment designed for spoken

,
ak
that your "neat, inexpensive solution" to
-
DIVISION OF HYDROMETALS, INC communication, but ATIS will sound like a
ROCKFORD, ILLINOIS 61101 U.S.A. the program- sharing problem will be
achieved with cassettes. am planning to
I
canary. Bob Brown, Atlanta, Ga.
buy a microcomputer. When asked why I Identification would require 176 bits of
wanted one, came up with the following
Corning Up In The October
I

planned uses: Files Management (adapta-

tion for record -keeping in a small busi-
would require 1.76 seconds.
Goldberg, Warrington, Pa.
-
information. Transmitting this at 100 baud
Stuart

ness); Teaching Programs (programmable

How right you are! It's 22 characters
P(i!I)tllar Electronics learning via teletype or CRT display); Soft-
ware Experience; Academic and Job Aug- times 8 bits divided by 100 baud equals 1.76
mentation (doing work at home with a seconds. That's a SMOP (small matter of
THE "SENIOR SCIENTIST" CALCULATOR programming) for you.
DESIGNING SOLID -STATE OSCILLATORS
phone hook -up to a big plant); Home Re-
creation (for the sheer fun of it). Gary -
USING PHASE -LOCKED LOOPS

RHOMBIC ANTENNAS FOR TV

Walker, Gilroy, Calif.

We're still gathering computer club info

Out of Tune
and will alert respondents to them in the
WHAT'S NEW FOR HI -FI IN 1976 near future. Commencing with this issue's In "Build a Muscle Feedback Monitor"
"Computer Bits," the column will be (May 1975), the polarity of B2 in Fig. 2
bimonthly instead of quarterly. should be reversed.
6 POPULAR ELECTRONICS

www.americanradiohistory.com
 RESPONSE CURVE

30MHz

M2PRECISION MODEL 1472

VARIABLE
SWEEP TIME/GM
POWER
ILIUM 521.521
20
105 t 20
Lo
M
)2

SEC
V S LV
CH POSRNIN
INTENSITY CAe
aL Sx wAc
-TRIGGERING-
LEVEL
nNL art0

aOURCc
PIA WRExf 1

VARIABLE VARIABLE
VOLTS /CM VOLTS /CM

:KPFAECISION
Model 1472 Dual --ace
Oscillcscope: 27MHz modu-
lated carrier and original
4 audio dis3layed.. $599.00

Model 1472 Dual Trace Scope has reliable auto- obtained on waveforms with as little as 1 cm deflec-
matic sync and plenty of deflection for waveform tion. Dual trace display has algebraic addition and
analysis at frequencies far beyond its nominal subtraction and differential input capability. Mode
range. Look at its actuall, smooth roll -off curve and automatically shifts between CHOP and ALTER-
you can see how you can do an expensive scope's NATE as you change sweep time, speeding set -up.
job with our far less costly but equally reliable, Extremely flat in -band response is particularly use-
easy -to -use counterpart. Model 1472 lengthens the ful for demanding applications like adjusting color
B &K- Precision complete line of 2 to 10MHz band- video to close tolerances in TV broadcast studios.
width scopes -a line o= scopes that now outsells
Front panel X -Y operation uses matched vertical
every other 10 to 15MHz scope because our users
have discovered our reliability, performance and amplifiers, preserving full calibration accuracy for
instant delivery from our distributors. both amplitude and phase. The intensity modula-
tion input (Z axis) is available for time or frequency
Model 1472 has 19 calibrated sweeps- .5;I.SEC /cm markers. Bright blue P31 phosphor and variable
to .5SEC /cm and sweep to .11 SEC /cm with 5x and illuminated graticule make any waveform easy
to 1.5SEC /cm with uncalibrated vernier. Deflection to see.
factor is 0.01V /cm to 20V/cm 5% in 11 ranges In Stock For Free Trial
plus fine adjustment. Regulation maintains calibra- Model 1472 or any B &K- Precision oscilloscope can
tion accuracies over 105- 130VAC range. Rise time be obtained from your local distributor for a free
is 24nSEC, fast enough to check most digital logic trial. You'll find the scope you need in stock today.
circuitry, including CMOS. Automatic triggering is Write for detailed specifications.

«PRECISION
PRODUCTS OF DYNASCAN
1801 W. Belle Plaine Avenue Chicago. IL 60613
CIRCLE NO. 10 ON FREE INFORMATION CARD
SEPTEMBER 1975 7

www.americanradiohistory.com
 Whe do
the pros geit (heir
tmining?

Almost half of the successful TV servicemen have

home study training and with them, it's NRI 2 to 1.
It's a fact! Among men actually making their living repairing
TV and audio equipment, more have taken training from NRI
than any other home study school. More than twice as many!
8 POPULAR ELECTRONICS

www.americanradiohistory.com
Not only that, but a national
survey,* performed by an
independent research
organization, showed that the
pros named NRI most often as
a recommended school and as
the first choice by far among
those who had taken home
study courses from any school.
Why? Perhaps NRI's 60 -year
record with over a million
students...the solid training 25" Diagonal Color TV... Widest Choice of
and value built into every NRI
course...and the designed-for- Professional Instruments Courses and Careers.
learning equipment originated As a part of NRI's Master NRI doesn't stop with just one
by NRI provide the answer. Course in TV /Audio servicing, course in TV /Audio servicing.
But send for your free NRI you build a big-screen solid You can pick from five
catalog and decide for yourself. state color TV with every different courses (including an
modern feature for advanced color course for
great reception and practicing technicians) so you
performance. As you can fit your training to your
build it, you perform needs and your budget. Or,
stage -by -stage you can go into Computer
experiments designed Technology, learning on a real,
to give you actual digital computer you build
bench experience yourself. Communications
while demonstrating with famous Johnson
the interaction of transceiver. Aircraft or Marine
various stages of the Electronics. Mobile radio,
circuitry. And your and more.
TV comes complete
with console cabinet, Free Catalog...
an optional extra No Salesman Will Call.
with other schools.
Likewise, NRI's Send the postage -paid card
Two Famous Educators... instruments are a cut above for our free color catalog
NRI and McGraw -Hill. the average, including a 31/2 showing details on all NRI
digit precision digital electronics courses. Lesson
NRI is a part of McGraw -Hill, plans, equipment, and career
world's largest publishers of multimeter, triggered sweep 5"
oscilloscope, and integrated opportunities are fully
educational material. described. Check card for
Together, they give you the circuit TV pattern generator.
They're top professional information on G.I. benefits.
kind of training that's geared No obligation, no salesman
for success...practical know- quality, designed to give you
years of reliable service. You will call. Mail today and see
how aimed at giving you a real for yourself why the pros
shot at a better job or a can pay hundreds of dollars
more for a similar course and select NRI two to one!
business of your own. You
learn at home at your not get a nickel's worth extra
convenience, with "bite- size" in training and equipment. If card is missing, write to:
lessons that ease learning and
speed comprehension. Kits
designed to give you practical
bench experience also become
first -class professional
RI . NRI SCHOOLS
instruments you'll use in your McGraw Continuing Education Center
work. CAI* i/! 3939 -Hill
Wisconsin Avenue,
Washington, D.C. 20016
'Summary of survey results upon request.
1
SEPTEMBER 1975 11

www.americanradiohistory.com
 put in stereo mode, and an Automatic Pro- line is clamped to about 1 volt, which blows
tection Circuit for amplifiers and speakers. the line fuse normally used with the equip-
Claimed FM sensitivity is 1.8 pV (IHF), ment. The unit is housed in a waterproof
stereo separation 50 dB (a 10,000 Hz, har- enclosure with aluminum r -f shielding, and
monic distortion 0.3% (stereo), and cap- looks much like a small electrolytic
ture ratio 1.5 dB. The amplifier is rated at 12 capacitor with two flexible leads. The Vol -
W rms /ch (30 W /ch stereo), over a power tector can be used with either positive- or

New Products bandwidth of 20- 20,000 Hz with 0.5% THD negative -ground 12 -V systems. $29.50
into 8 ohms. The Model 1620 measures CIRCLE NO. 74 ON FREE INFORMATION CARD

223/4" Wx 15" D x 6" H (57.2 x 38.1 x 15.2

Additional information on new products
covered in this section is available from cm) and weighs 33 lb (15 kg). Includes
grained walnut veneer enclosure. $499.95. HELECTRONIX FUNCTION GENERATOR KIT
the manufacturers. Either circle the item's
code number on the Reader Service Card CIRCLE NO. 71 ON FREE INFORMATION CARD The Model L -10 Function Generator kit by
inside the back cover or write to the man- Helectronix has a pre -wired and pre- tested
ufacturer at the address given. INFINITY MONITOR II LOUDSPEAKER SYSTEM circuit board to facilitate assembly. Fre-
Infinity System's new Monitor Il is a floor -
standing, four -way loudspeaker system,
AP PRODUCTS BREADBOARDING STRIPS Program material ranging from 23 to 450
A new series of terminal and distribution Hz is reproduced by a patented long -throw
strips is available from AP Products. These 12 -inch (30.5 -cm) damped woofer. A
11/2-inch (3.8 -cm) enclosed midrangedriver
solderless, plug -in strips are available in
three basic configurations of terminal is active in the 450 -5000-Hz range, while a
1 -inch dome tweeter covers 5000 to 10,000
strips and two versions of distribution
Hz. A Walsh Transmission Line Tweeter,
which looks like an ice cream cone, han-
dles material in the 10,000- to 28,000-Hz
range with 360° horizontal dispersion. The
Monitor II's floor- standing, oiled walnut quency range is claimed at 1 Hz to 100 kHz
enclosure comes with two tops -one oiled with amplitude constant ±0.5 dB. Sine out-
walnut and one cloth -wrapped. The system put with variable amplitude up to 10 Vpp
is not recommended for use with amplifiers into 600 ohms is said to contain less than
rated at less than 60 W rms/channel. Nomi- 2% distortion. The generator's triangle
nal impedance is 8 ohms. The Monitor Il wave is claimed to have a typical linearity of
measures 50" H x 17" W x 16"D (127 x 43.2 0.1 %, with variable amplitude output up to
x 40.6 cm) and weighs 94 lb (42.7 kg). 12 Vp into a 600 -ohm load. The square
CIRCLE NO. 12 ON FREE INFORMATION CARD wave and pulse (variable width) output has
a fixed amplitude at TTL logic one (greater
GEMTRONICS MOBILE CB TRANSCEIVER than 3 V) levels. Rise and fall times are said
to be less than 15 ns. Duty cycle of the pulse
The newest addition to Gemtronics' line of output can be varied from 5 to 95 %. Fanout
strips. The Model L terminal strips contain CB transceivers is the Model GTX -23 is 30 gates, according to the manufacturer.
two rows of 5- tie -point terminals, are avail- mobile rig. Among its features are a fre- The L-10 weighs 2 lb (0.9 kg) and measures
able in four lengths, and are said to ac- 7" x 5" x 4.5" (17.8 x 12.7 x 11.4 cm).
commodate all components and jumpers $49.95
with leads up to 0.032" (0.8 mm) diameter. CIRCLE NO. 75 ON FREE INFORMATION CARO

The full -length model will hold eight 14 -pin

DIP's. The Model R terminal strips are
UHER LIGHTWEIGHT STEREO HEADPHONES
available with either one or two rows of
4- tie -point terminals and are useful in Uher of America is offering a pair of open -
breadboarding circuits using standard air headphones in three configurations.
DIP's. Distribution strips are available in The Model W674 has a two -pin plug for use
two models. The first consists of two con- with Uher open reel decks, the Model W675
tinuous bus strips (three lengths available), has a 5-pin plug for use with Uher cassette
and the second consists of two groups of decks, and the Model W676 has a phone
three-bus strips. All buses are comprised of quency synthesizer providing 23 crystal- plug termination for use with amplifiers
4- tie -point terminals. All contacts are controlled transmit and receive channels, having the standard headphone jack. The
nickle -silver copper alloy. Price varies from three -position delta tune, PA/CB opera- headphones have a frequency response of
'$2.00 to $12.50, depending on model. tion, S /r -f meter, a modulation indicator 20 to 20,000 Hz. It is said that they weigh
CIRCLE NO. 70 ON FREE INFORMATION CARD
lamp and noise limiter. only 2.2 oz (62 g), and permit you to hear
CIRCLE NO. 13 ON FREE INFORMATION CARO external sounds as well as the program
MAGNAVOX MX 4 -/2- CHANNEL material. An eight -foot (2.4-m) cord is in-
AM/FM STEREO RECEIVER OVER -VOLTAGE PROTECTION FOR MOBILE cluded. $49.95
EQUIPMENT CIRCLE NO. 76 ON FREE INFORMATION CARD
The MX Model 1620 receiver from Mag-
navox features four power amplifiers, SQ The Voltector, by D.R. Corbin Manufactur-
MAXELL RECORDING TAPES
and RM decoders, and a full complement ing Co., is a solid -state over-voltage protec-
of controls. The tuner section features the tion device for 12 -V dc mobile equipment. Maxell has introduced two new lines of re-
ASNC system (which reduces noise level A PUT is used in a voltage comparator that cording tape. A family of premium cas-
on weak stereo stations) and three dual - is said to track ±0.5 volt from 20°F to 200 °F settes will be known as the UDXL series,
gate MOSFET's in the front end. The am- ( -6.7 °C to 93.3 °C). The comparator output available in 60- and 90- minute packages.
plifier section has a direct-coupled output, feeds a high- current thyristor switch that Epitaxial blending techniques of pure and
a power boost circuit to double power out- crowbars the supply line. Voltage on the alloy ferrites provide large dynamic range,
12 POPULAR ELECTRONICS

www.americanradiohistory.com
 MITS Altair Computer Report II
MITS Announces Lower Memory Prices!
On July 1, 1975, MITS lowered the price of the Altair 1K Static The 1K Static Memory Card contains 1024 bytes of memory
Memory Card (88-1MCS). The kit price was dropped from $176 with a maximum access time of 850 nanoseconds.
to just $97 while the assembled price was dropped from $209 Now ready for production is the new Altair 2K Static Memory
to $139. Card (88 -2MCS) with 2048 bytes of memory. Like the 1K Static
This price reduction was made possible by a reduction in the Memory this new card contains memory protect features and
price of the Altair 1K 8101 memory chips. provisions for disabling the ready.
Also affected was the price of 88 -MM 256 byte (word) memory It has a maximum access time of 850 nanoseconds and is
modules. The $53 kit price was lowered to just $14 and the $61 engineered with the finest components available. It is inexpen-
assembled price to $26. sively priced at $145 kit and $195 assembled.

Altair BASIC -Not Just HARDWARE PRICES:

Altair Computer kit with complete assembly instructions
Assembled and tested Altair Computer
1,024 Byte Static Memory Card
$439
$621
$97 kit and $139 assembled

Anybody's BASIC 2,048 Byte Static Memory Card

4,096 Byte Dynamic Memory Card
Full Parallel Interface Card
$145 kit and $195 assembled
$264 kit and $338 assembled
$92 kit and $114 assembled
Serial Interface Card RS232) $119 kit and $138 assembled
Serial Interface Card (TTI. or Teletype) _$124 kit and $146 assembled
Altair BASIC is an easy -to -use programming language that can COMTER II.
.. _

$780 kit and $920 assembled

solve applications problems in business, science and education.
You will find that with only a few hours of using BASIC that
'The Comter II Computer Terminal has a full alpha -numeric keyboard and a
you can already write programs with an ease that few other com- highly readable 32- character display. It has its own internal memory of 256
puter languages can match. characters and complete cursor control. Also has its own built -in audio cassette
Altair BASIC doesn't compromise power for simplicity. While interface that allows you to connect the Comter II to any tape recorder for
both storing data from the computer and feeding it into the computer. Requires
it is one of the simplest computer languages in existence, it is an RS232 Interface Card.
also a very powerful language.
SOFTWARE PRICES:
ALTAIR BASIC comes in three versions. The first of these is a Altair 4K BASIC $350
Purchasers of an Altair 8800, 4K of Altair Memory, and Altair Serial I/O or
4K BASIC designed to run in an Altair with as little as 4,000 words ONLY $60
Audio -Cassette I/O
of memory. This powerful BASIC language has 6 functions (RND, Altair 8K BASIC $500
SQR, SIN, ABS, INT, and SGN) in addition to 15 statements (IF .. . Purchasers of an Altair 8800, 8K of Altair Memory, and Altair Serial I/O or
Audio- Cassette I/O ONLY $75
THEN, GOSUB, RETURN, FOR, NEXT, READ, INPUT, END, DATA $750
Altair EXTENDED BASIC
GOTO, LET, DIM, REM, RESTORE, PRINT, STOP) and 4 commands Purchasers of an Altair 8800, 12K of Altair Memory, and Altair Serial I/O or
Audio -Cassette I/O ONLY $150
(LIST, RUN, CLEAR, SCRATCH).
Altair PACKAGE ONE (assembler, text editor, system monitor)
The second ALTAIR BASIC option is the 8K BASIC designed Purchasers of an Altair 8800, 8K of Altair Memory, and Altair I/O ONLY $30
to run in an Altair with as little as 8,000 words of memory. This NOTE: When ordering software, specify paper tape or cassette tape.
BASIC language is the same as the 4K BASIC only with 8 addi-
tional functions (COS, LOG, EXP, TAN, ATN, INP, FRE, POS) and Warranty: 90 days on parts for kits and 90 days on parts and labor for assembled
4 additional statements (ON ...GOTO, ON ... GOSUB, OUT, units. Prices, specifications, and delivery subject to change.
DEF) and 1 additional command (CONT). This BASIC has a multi-
tude of advanced STRING functions and it can be used to control

languages.
-
low speed devices features not normally found in many BASIC MAIL THIS COUPON TODAY!
Enclosed is check for S

The third ALTAIR BASIC is the EXTENDED BASIC version or Master Charge #
BankAmericard #
designed to run on an Altair with as little as 12,000 words of
Altair 8800 Kit Assembled Options
memory. It is the same as the 8K BASIC with the addition of Include $8 for postage & handling (list on separate sheet)
PRINT USING, DISK /O, and double precision (13 digit accuracy)
I

add, substract, multiply and divide. Altair Users Group Associate Software Documentation
Please send free literature
Altair BASIC is only the beginning. MITS is currently engaged NAME
in an extensive software development program. Other software
ADDRESS
now available includes an Assembler, System Monitor, and Text
Editor. CITY STATE & ZIP

Altair software comes with complete documentation. MITS/6328 Linn N.E., Albuquerque, NM 87108 505/265 -7553 or 262 -1951

One Month Specials

The Altair Users Group is quite possibly the largest computer
hobbyist organization in the World. It is both a means of communi-
cation among Altair Users and a method of building a comprehen-
sive library of Altair programs. All Altair 8800 owners are entitled L_.
to a free, one year membership in this group.
For one month only, you can become an Associate Member for
one year at a reduced rate of $10 (regularly $30). Among other
benefits you will receive a subscription to the monthly publication,
Computer Notes, which contains complete update information on
Altair hardware and software developments, programming tips,
general computer articles and other useful information.
"Creative Electronics"
Now available is the Altair Software Documentation Book I which
contains technical data on the Altair Assembler, Text Editor, System
Monitor and BASIC language software. This documentation is free
to purchasers of Altair BASIC. For one month only, it is being
offered for only $7.50 (regularly $10). MITS/6328 Linn N.E., Albuquerque, NM 87108 505/265 -7553 or 262 1951
Offers good until September 30, 1975.
CIRCLE NO 31 ON FREE INFORMATION CARO
SEPTEMBER 1975 13

www.americanradiohistory.com
jwn-w
high sensitivity, uniform distribution and SCOTT DIGITAL FM TUNER
wide frequency response, according to The Scott T33S digital stereo FM tuner
Maxell. Other features are a redesigned uses MSI and phase -locked -loop circuitry,
package with side and tape travel indica- digital frequency readout, a MOSFET r -f
tions, a built-in 5- second cueing line, and a front end, two pre -tuned phase-linear -f i

head cleaning leader. Also being intro- filters, and a quartz crystal reference stan-

A/\/1111- 0.1 Hz. to 100 KHz.

duced is a new high -level mastering tape
known as Ultra Dynamic back -coated tape.
Maxell claims that this tape can provide a
flat response over the range of 20 to 24,000
dard. Frequency selection is accomplished
by automatic or manual scan, or by using
prepunched cards for preferred stations.
Channel spacing is set at 100 kHz, and de-
Hz when properly biased (about 115% bias emphasis is switch -selected (50 or 75
current). The conductive back coating is µsec), which allows the tuner to be used in
said to provide good capstan traction and either the U.S. or Europe. The tuner will
bleedoff of static charges. The new UD work on 120 or 240 V ac. Among other fea-
back coated tape will be marketed in 7- and tures are a front panel Tape Out jack, both
10 -inch reel formats. upscale and downscale scanning, a mute
CIRCLE NO 17 ON FREE INFORMATION CARD control, hiss filter, and gas- discharge dis-
play. Specifications include 1.8NV IHF sen-
sitivity; frequency response, 20- 15,000 Hz
SANSUI CASSETTE DECK
1 dB; tuning accuracy, 0.001 %; and an

Sansui's new Model SC363 stereo cassette image rejection of 85 dB. The tuner mea-
deck boasts a magni -crystal ferrite head, a sures 17.5" x 11.6" x 5.3" (44.5 x 29.5 x
4 -pole hysteresis synchronous drive 13.5 cm). $999.95.
motor, high- inertia flywheel, and belt- CIRCLE NO. 79 ON FREE INFORMATION CARD

HEATH PORTABLE DIGITAL MULTIMETER

For only $39.95 Heathkit's IM -2202 DMM uses a recharge-

able NiCd battery pack (included) and a
Our new FG -2 Function Generator kit built -in charging circuit for portable opera-
gives you all five of the most useful
waveforms for design and testing at one
fourth the cost of previous similar in-
struments. Thanks to improved IC's the
FG -2 now features amplitude stability
of + 1 db over any range, Sine wave
distortion of less than 1% from 20 Hz. to
20,000 Hz. and an output of 4.0 Volts
peak -to -peak with adjustable offset. The driven capstan. The transport has fail -safe
offset selector lets you put the positive devices, which according to Sansui elimi-
peak, negative peak, or the center of the nate tape jamming, stretching, and break-
waveform on DC ground. The DC coupled age. A photelectric sensor stops the tape
circuit keeps the waveforms in exactly automatically when it reaches either end. tions. Up to eight hours of continuous op-
the same position no matter what the Other features are low -noise circuitry, eration can be obtained from each charge.
level control setting. Dolby -B noise reduction, a line /mic short- Its 26 ranges include full scales of 100 mV
ing circuit to eliminate hum, provisions for to 1000Vdc, 100 mV to 750 V ac, 100pAto
Gray impact plastic case 5'
x 63/ x 2 %. a stereo headphone, and a no -click pause 1000 mA, and 100 ohms to 1000 kilohms.
115 Volts 60 cycle power supply included. button. Wow and flutter are claimed at less The meter's 100% overanging capacity op-
than 0.12% (WRMS) and tape speed accu- erates on all ranges except 1000 V dc and
FG -2 Function Generator Kit racy at 1.5 %. Winding time is less than 70 750 V ac, giving full 2 -A and 2- megohm
shipping weight 3.0 lbs $39.95 PPd seconds for a C60 cassette. Frequency re- capability. According to Heath, internal
sponse is 30 to 13,000 Hz for standard tape, standards supplied with the kit allow field
GET OUR
and 30 to 16,000 for Cr02. $279.00 calibration to 0.5% (dc) and 1% (ac). Better
NEW 1975 CIRCLE NO. 78 ON FREE INFORMATION CARD accuracy can be obtained using lab stand-
ards. The 31/2 -digit display features au-
CATALOG B &K 6 -DIGIT AUTORANGING FREQUENCY COUNTER tomatic polarity indication and decimal
point placement. $179.95.
B &K's new model 1801 is a six -digit au-
listing this and other unique kits toranging frequency counter with a CIRCLE NO. 5 ON FREE INFORMATION CARD

R E guaranteed measurement range of 20 Hz to

"F E" 40 MHz with a typical accuracy of 10 PPM.
E &L MICROPROCESSOR SYSTEM
by simply circling our number A front panel switch selects either a "1
SEC" preset gate interval or the "AUTO" A new Microprocessor System is being in-
on the reader service card. troduced by E &L Instruments. The basic
range. The display consists of 7- segment
solid -state numerical digits, and three system provides a CPU and interface con-
LED's for units (kHz and MHz) and over - trol built around Intel's 8080 microproces-
SOUTHWEST TECHNICAL ange indication. A 10-MHz crystal time sor chip, a memory card featuring 1K of
SiuTr! PRODUCTS CORPORATION base is incorporated, but an external time read and write memory space and a 256 x 8
base can also be used. The 1801 measures PROM, a front panel, power supply, and an
DEPT. PE
101/2" D x 8- 11/16" W x 3- 5/16" H (26.7 x interface board. The front panel controls
219 W. Rhapsody 22.1 x 8.4 cm), and weighs 4 lb (1.8 kg). have priority over software, load 16 bits of
San Antonio, Texas 78216 $230.00 address data, reset and suspend functions
CIRCLE NO. 83 ON FREE INFORMATION CARD over the system program. The system is
CIRCLE NO. 53 ON FREE INFORMATION CARD
14 POPULAR ELECTRONICS

www.americanradiohistory.com
 SBEI
scans any
station in
the nation

16,000 different, digitally -derived f-equencies

instantly at your command. Haar eiery "a.tion"
station within range, 30- 50MFz,153- 170MHz,
450- 470MHz and 490- 510MHz.
Cards easily programmed from lis- supplied.
Simple visual check of program.
Insert card in slot for instant 10 c annel
program change even while mob le. Without ecual
when traveling by car, truck, RV, boat.
Smallest size and only crystal -less scanner
with integral power supply for 12'/)C and 115VAC.
USE FOR BASE OR MOBILE.
No confusing, error -prone switches, tabs,
mechanical gadgetry. Permanent c and -nemory
eliminates need for continual re- programming.
Get the complete story on OPTISOAN -write now
for 4 -color descriptive brochure.

tazi =1
LINEAR SYSTEMS, INC.
220 Airport Blvd. Watsonville, CA 95076

IN- ERNATIONAL OFFICES.

S. GOULD MARKETING CO., LTD. LINEAR SYSTEMS, S.A.
5 Rue des Alpes, P.O. Box 1613,
Quebec, Canada H4T, 1S9 1211 Geneva 1, Switzerland

CIRCE NO 19 NN FREE INFORMATION CARO

SEPTEMBER 1975 15

www.americanradiohistory.com
Sound reasons 1 thru 5
easily expanded, with the following op-
why an SAE gives tions available: synchronous communica-
you what you pay for. tions interface; printer output; priority in-
You are an audio connoisseur. You know exactly terrupt with a real -time clock; D/A conver-
what you are looking for in audio components. ters; A/D converter with 8 channels of MPX;
The right features. The right functions. The right 4K of read -write memory (up to 64K total),
power. But you can't find one at the right price.
And you won't. What you're looking for costs 2K PROM (ultraviolet erasable) memory,
plenty to produce. Some build additional price
right into their units. We build additional unit
into our price. Here are some reasons why an SAE
gives you what you pay for.
and cassette /O. Computer interfacing,
I

hardware development and software are

taught through the "Bugbooks" III and IV
New Literature
(included).
S YEAR FREE SERVICE CONTRACT CIRCLE NO. 80 ON FREE INFORMATION CARO
SAE -first In tie industry to offer a I.i
TRANSFERABLE FULL S YEAR' FREE
SERVICE CONTRACT on parts. labor and SHAKESPEARE WHIP ANTENNA CATALOG
performance epecifiutlone. This contract DRAKE GENERAL COVERAGE RECEIVER
covers SAE'S complete line of audio
prOCYCte when relurned to the factory or
Shakespeare has released its latest catalog
an authorized service agency. ._
R.L. Drake's new Model SSR -1 is a syn-
of the Royal line of fiberglass whip anten-
thesized radio receiver capable of desk-
nas. Radiators for CB mobile, base station,
We start with a Free Five Year Transferable top or portable operation over a range of
Service Contract. It's on parts, labor and and marine operation, as well as mounting
500 kHz to 30 MHz on AM, Upper or Low-
specifications. If you're a connoisseur, hardware, co- phasing harnesses, and gut-
you'll demand it.
ter clips are described. The White Knight
base -loaded whip is representative of the
We design each product from the line, featuring a tuning -screw adjustment
strict requirements of professionals.
After a unit has passed our rigid for minimum SWR, and a helical coil in a
engineering and quality control sealed enclosure, which the company
standards, it must meet the demands claims helps keep feedpoint impedance
of professional use. Road testing. Testing that
requires extreme power handling for longer periods constant. For base operation, the
of time. Testing that requires surviving continual Greyhound, a 5/8-wave antenna, uses a
movement from place to lace. All of which simply
means that each unit will work that much better in capacitive "hat" to reduce static and radia-
your home. tion angle. All Shakespeare antennas are
The professional approach led to er Sideband (selectable), and CW. The re- rated to full legal power without burn outs.
the development of the "Steady- ceiver is supplied with a built -in speaker, Address: Shakespeare Industrial Fiber-
State" audio component. A com-
ponent that lasts longer because removable telescoping whip antenna, hol- glass Div., Jefferson Sq., P.O. Drawer 246,
it's built as an efficient package to ders for 8 D cells, and a built -in, switchable Columbia, SC 29202.
perform perfectly under highest
demand conditions. 117/234 V ac power supply. With batteries
installed, the SSR -1 will automatically CB RADIO ACCESSORIES CATALOG

switch to battery operation if ac power fails An 8 -page catalog from GC Electronics il-
or the line plug is pulled. For reduced cur- lustrates and describes its line of CB and
rent drain on battery power, the dial lamps amateur radio replacement parts and ac-
do not light up unless a red pushbutton on cessories. Items such as base and mobile
the front panel is depressed. Include microphones, SWR meters, noise filters
coarse and fine tuning controls, preselec- and suppressors, and mike and antenna
Our product, its professional appearance and its tor, clarifiers, S meter, and headphone connectors are featured. Address: GC
unique features, create their own reasons for jack. Electronics, 400 South Wyman, Rockford,
costing more. Like our Mark XXV Stereo Power
Amplifier. It features Parallel- Series -Output CIRCLE NO RI ON FREE INFORMATION CARD IL 61101,
circuitry (PSO). Forced air cooling. Triple diffused
output transistors. Dual relay protection circuits. EICO CONVERTER /CHARGER
CTS SPEAKER UNE
As if these were not enough to justify its $1250
price, the unit delivers a minimum of 300 Watts An 8 -page catalog featuring CTS of
RMS per channel into 8 Ohms, both channels
A solid -state power supply, Model 1040,
Paducah's line of high -fidelity loudspeak-
driven from 20Hz- 20kHz, ±.25dB, with no more which permits auto stereo tape players or
than 0.05% total harmonic distortion from 250mW ers. Twenty -four models are now available,
mobile CB rigs to be operated at home, has
to rated output. Yet it weighs less than 60 pounds ranging from a 13/4 -inch tweeter with a fre-
(lift others with the same specs). been introduced by Eico Electronic In-
quency response of 2000 to 20,000 Hz to a
strument. Twelve -volt dc equipment can be
12 -inch woofer with a 50 -watt power rating
operated from 120-V ac lines or can be
and a response of 20 to 2000 Hz. All CTS
checked out prior to installation in a car or
speakers are designed with an 8 -ohm nom-
boat. It can also be used as a charger for
inal impedance measured at 400 Hz. Ad-
12 -V batteries. Input: 120-V ac, 50 -60 Hz;
It all started here with our 2500 dress: CTS of Paducah, Inc., 1565 N. 8th
professional version shown with rack output: 12 -V dc at 4 A continuous. $19.95
St., Paducah, KY. 42001.
mount for professional use. (wired only).
There are many other reasons. Send us the attached
WATTS RECORD CARE BOOKLET
coupon and we'll send you an additional 25, CIRCLE NO. 82 ON FREE INFORMATION CARO

plus literature, and the location of a dealer who'll A new 27 -page booklet entitled, "Watts,
be able to supply even more. Just For The Record," is available for $1
Components for the Connoisseur RECORDING TAPE/TIME SLIDE RULE
from Elpa Marketing. The booklet discuss-
The Tape Measure&' is a double -slide es static and dust build -up on phonograph
cardboard slide rule which computes the discs and styli, and how to keep them
amount of recording or playing time left on clean. The Watts line of record care pro-
Scientific Audio Electronics, Inc. PE -9/75 a given length of tape. The slide rule can be ducts is illustrated, and explicit directions
P.O. Box 60271 Terminal Annex, used with regular 5 -, 7- and 101/2 -inch are given for their use. The booklet also
Los Angeles, California 90060 gives tips on handling records, storing and
I want more reasons, thank you.
open -reel tapes. Calibrated time scale
Name ranges from 2 minutes to 24 hours. Availa- washing them, and how to keep the stylus
Address ble for $1.84 from the Rothchild Printing in good condition. Address: Elpa Market-
City State Zip Co., 7900 Barnwell Avenue, Elmhurst, NY ing Industries, Inc., New Hyde Park, NY
11373. 11040.
CIRCLE NO 47 ON FREE INFORMATION CARD
16 POPULAR ELECTRONICS

www.americanradiohistory.com
 five new Continental Specialties Corp. offers
a total line of breadboarc tesi devices
... everything from inexpensive kits
breadboard testers to high -power professional units and

=0=
logic monitors too. Each high quality,
compact unit comes with a guarantee

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bt.t five of the "hottest" tens we make...

PROTO BOARD
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Ready -to -use. Just plug in and start Bus Strip; 2 E -way binding posts; 4 rubber feet;
building!
2 extra floating 5 -way binding
screws and easy assembly iistruetiois. 4.E0"
posts for external signals (PB -203 only). Completely
self- contained with power switch, indicator lamp and power (114.3mm) wide x 6.00" (152.4mm) long x 1 35"
fuse. 24 14 -pin DIP capacity. All metal construction ... (34 3mm) high. Order your PB -100 k't! Start building
no chipping or cracking as with plastic cases. Two -tone and testing now!
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4
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3
4
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OT-59B Bus Strips
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1 0T -47B Bus Strip 1 QT-47B Bus Strip Trace signals or troubleshoot
Fuse Power Switch Fuse Power Switch
Power -On Light Power -On Light fast. Inject signa s or wire
9.75 "L x 6.6 "W x 3.25 "H 9.75 "L x 6.6 "W x 3.25 "H unused circuits into existing
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1 5V, 1AMP regulated power construction eliminates
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- 15V, V2 AMP regulated high density pc boards.
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PC -14 14-pin Proto -Clip: $4.50 ea.

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CIRCLE NO 15 ON FREE INFORMATION CARD

SEPTEMBER 1975 17

www.americanradiohistory.com
 You can tear out
alithecards
in this magazine...
But this is the one
you should mail!
If you're thinking of investing your money
in a learn-at -home program in electronics, there are
a few things you should know first.

Selecting a home electronics program At Bell & Howell Schools, you get
isn't easy. It could be one of the most all that ...and so much more!
important decisions you'll ever make for Bell & Howell Schools has been in the
your future. So you want to decide care- home -study electronics business a long
fully and get the best education you can. time. Almost half a century. In that time,
After all, you're investing your time we have developed teaching techniques
and money, and you want a full return on that provide our students with the most
that investment. vital and comprehensive learning system
What should you look available for at -home study.
for before you select a school?
You probably want a school with a Techniques like our "step -by- step"
proven track record of quality and per - concept of learning.
formance.You want personal attention At Bell & Howell Schools, we start you
plus, the convenience of learning at home. off with the basics. Then take you step by
You want the most up-to-date technical step through the learning process. You
texts... teaching aids and learning work at a comfortable pace -not too
methods. fast... not too slow. If you already have
But most of all you want to actually some learning or experience, we'll arrange
learn what electronics is all about. Not advanced standing in the program so you
just theory, but actual hands-on experi- can skip the beginning lessons. And don't
ence with the latest and best technical worry if you don't have any electronics
equipment available today! background. 25% of our graduates never

18 POPULAR ELECTRONICS

www.americanradiohistory.com
 even had any electronics training before What better way to learn So in addition to the exclusive "Electro
enrolling with Bell & Howell Schools. electronics than to actually work Lab ®" system that you will build as part of
(Based on a recent survey of our graduates Bell & Howell's Home Entertainment Elec-
conducted by an independent research
with electronics equipment? tronics program, you'll also build a 25"
firm. Survey results available on request.) And what better way to find out how diagonal color TV with digital features.
things fit together...how they work and Sounds exciting, doesn't it? Well,
Or our system of personal contact. why they work than to actually build the digital electronics is exciting! Its growth
equipment? And we don't mean gadgets and application are giving us new and
No course is without its problems. And that will be worthless to you later.
when you get hung up on a problem, you better products and a whole new realm of
We mean equipment like the Bell & split -second accuracy that was just a
want answers and you want them fast. Howell Schools exclusive " Electro-Lab ®"
Here at Bell & Howell Schools, we corn- dream a few years ago. And this new
electronic training system including technology is being applied more and
bane the convenience and pleasure of design console, digital multimeter and
learning at home with a system of per- more to TV's, clocks, radios and other
oscilloscope, that you can use profes- home entertainment equipment.
sonal contact with faculty and other sionally after you've graduated.
students that rivals -if not beats -any By studying with Bell & Howell Schools
The design console will allow you to set -one of the first schools to introduce
other program available. up and examine circuits without having
For problems that "just can't wait" we digital electronics as part of its training
to solder them in place. program -you can actually get in on the
have a toll -free "hot- line" that you can The digital multimeter measures volt-
call and discuss your questions with an ground floor of this new technology
age, current and resistance and displays while learning all the basic electronics
experienced instructor. You get real
-
attention someone whose only job is to
see to it that your individual questions
its findings in big clear numbers for easier
reading.
principles and skills you'll need to detect
and troubleshoot problems professionally
And the solid-state "triggered sweep" on digital and other electronic equipment.
are answered. And answered quickly oscilloscope is similar in principle to the
and clearly! Make no mistake about it! As you
kind used in hospital operating rooms to build your digital color TV, you'll get a
To help you develop your thoughts monitor heartbeats. But you'll use it to
and understand electronics principles thorough grounding in electronics prin-
monitor and analyze tiny integrated ciples. You'll develop a working knowl-
more thoroughly, Bell & Howell Schools circuits. And you'll find the "triggered
has developed a unique feature that no edge of "state of the art" integrated
sweep" feature locks in signals for easier circuitry and the 100% solid-state chassis.
other learn-at -home program has -In- observation.
Person Help Sessions in 50 major cities Plus you'll actually know how to program
throughout the United States. These let That's not all you build when a special automatic channel selector to
skip over "dead" channels and how to
you get together with instructors and you choose a course from build a remarkable on-the -screen digital
other fellow students. There you can talk Bell & Howell Schools!
shop with other people who share your clock that flashes the time in hours,
To learn the most advanced electronics minutes and seconds.
irterests...explore your problems further technology, you have to work with the
.._ and get additional assistance. But most importantly, you'll have
most advanced
But that's not all that Bell & Howell the skills that could lead you to a
training tools.
Schools will do for you! In addition to
o -ir vast experience and expertise, is a
brighter future...
philosophy that the best learning comes And isn't that what education is supposed
from working with the best equipment to be all about? At Bell & Howell Schools
a'ailable. And that's exactly what our we've always thought so although no school
students do! can guarantee you a job or income oppor-
tunity. Get full details about us, our courses,
our philosophy of education by mailing the
postage-paid card today. If you take one of
our courses for vocational purposes, this
program is approved by the state approval
agency for Veterans' Benefits.
Mail card today for full details!

If card has been removed, write:

An Electronics Home Study School
DEVRY InSTITuTE OF TECHOOIDOV 763/4 R 1

ONE of THE

BELL E HOWELL SCHOOLS

4141 Belmont. Chicago. Illinois 60641
"Electra Lab*" is a registered trademark of the Bell & Howell Company.
Simulated TV test pattern.
SEPTEMBER 1975 21

www.americanradiohistory.com
 some differences in high- frequency
response can be expected as a result).
When they are, they provide an eerily
quiet background -quite obviously
the best signal -to -noise ratio, audibly

Stereo Scene and measurably, of any recording

medium in current use. Unfortunately,
their durability under any practical
playing situation is extremely poor.
By Ralph Hodges
STARTING WITH A LACQUER DISC Lacquer Noise. This outstanding
noise performance depends, of
ACCORDING to my sources, two records were cut. Today's cutting (in- course, on a good master tape (tape
United States companies, Cap- scribing) device is a precision cutting noise is usually dominant on any lac-
itol (formerly Audio Devices) and head mounted on a heavy worm - quer disc, as you soon become
Transco, are responsible for at least 90 gear- driven lathe (Fig. 1). The inscrib- aware), good electronics, and a very
per cent of the world's blank lacquer ing stylus, a tiny jewel arrowhead with consistent and well- defined inter-
discs for record cutting. Capitol has complex facets, is heated to ease its action between cutting stylus and
the larger share of the market -maybe passage through the lacquer material, lacquer material. How quiet is a lac-
55 to 60 per cent. Recently, joined
I while the coils of the cutting head, quer master that is not limited by tape
other members of the press on a trip to which must dissipate enormous noise? Well, Capitol claims to mea-
the Capitol plant in Winchester, Vir- amounts of power, are cooled, usually sure signal -to -noise ratios that are typ-
ginia, where the pictures shown here by a flow of liquid helium. ically about 65 dB with A weighting.
were taken. (I can't take credit for the The lacquer records made on this Hardly astonishing, you say, and in
photography since that belongs to a device are used to produce metal fact well within the proven capability
professional, Thomas Bancroft, who molds for vinyl disc pressing. They are of the tape medium. But the difference
was employed for the expedition). not intended to be played, although is that tape S/N is rated at a recorded
The blank lacquer disc is of course they can be with high -quality pickups level that comes rather close to the
the modern equivalent of the wax- or (keeping in mind that the stylus mass saturation point of the tape, while the
tinfoil- covered surfaces on which the and damping of pickup cartridges are lacquer S/N is referred to a recorded
first phonograph and gramophone designed for vinyl, not lacquer, and velocity of 3.54 centimeters per
second -a very moderate level in-
deed. Recorded velocities briefly ex-
ceeding 20 centimeters per second
have been found on commercial disc
records, and some of the better
playback cartridges (the consumer's
cartridge, not the recording system,
determines the upper limit for levels
on discs) are capable of around 30
centimeters per second at mid -fre-
quencies before mistracking. If the
lacquer has a 65-dB S/N at 3.54 cen-
timeters per second, the equivalent
S/N at 20 centimeters per second
would be about 80 dB. Now you begin
to understand how quiet the disc
medium can really be.
Basically, lacquer noise is low be-
cause the groove wall is smooth, with
a grain so fine that only the finest
scanning electron microscopes can
resolve it. This exquisite polish is ac-
quired through the action of the
heated cutting stylus on the lacquer
material. It is not known whether the
heat actually melts (briefly) the mate-
rial or simply softens it to facilitate a
smooth passage for the stylus, but it is
known that the right stylus tempera-
ture is critical for a quiet cut. (In fact,
temperature requirements change
from the outer grooves to the inner,
Fig. Disc -cutting lathe used for evaluation of lacquers.
1. where linear velocities are lower, so
Test cuts can be seen on the lacquer's surface. that a compromise must be made.)
22 POPULAR ELECTRONICS

www.americanradiohistory.com
 ll'nd only to the III.
The new Shure M95ED phono cartridge combines an ultra -flat 20- 20,000 Hz
frequency response and extraordinary trackability with an utterly affordable
price tag! To achieve this remarkable feat, the same hi -ti engineering team
that perfected the incomparable Shure V -15 Type Ill rartridae spent five
years developing a revolutionary all -new interior pole piece structure for
reducing magnetic losses. The trackability of the M95ED is second only to
the Shure V -15 Type Ill. In fact, it is the new "Number 2' cartridge in all
respects and surpasses much higher priced units that were considered
"state of the art" only a few years ago. Where a temporary austerity budget
is a pressing and practical consideration, the MÇ5ED can deliver more
performance per dollar than anything you've heard to data.

Shure Brothers Inc.

222 Hartrey Ave., Evanston, IL 60204
In Canada: A. C. Simmonds & Sons Limited SHIJRE
Manufacturers of high fidelity components, microphones, sound systems and related circuitry.
CIRCLE NO. 50 ON REE INFORMATION CARD
SEPTEMBER 1975 23

www.americanradiohistory.com
 disc side will accommodate. It has blanks. Reportedly he built up the
even been suggested that a non -flat coating in thin layers, letting each one
cutting surface may introduce a slight cure for a precise period of time, and
"warp wow," since the cutter head has so had to rise at all hours of the night
a certain amount of freedom to ride up to perform a fresh application. The
and down. Capitol technique (which we were not
What else? To a significant extent allowed to view) is a one -step process,
the motion of the cutting stylus is con- taking only a second or so for each
trolled by the compliance and damp- side. After each side is done there is a
ing the lacquer material presents, so trip through a curing tunnel (Fig. 3)
that linear performance of the system that is monitored constantly for tem-
requires a material that is both cor- perature and cleanliness. Then it's all
rectly constituted and homogeneous. over except for inspection, center-
The material should behave properly hole punching, and packaging, all of
under the stress of cutting, so that which involve clean -room environ-
forces "stored" during the modula- ments and elaborate handling precau-
tion of one groove do not work them- tions. During inspection, blanks for
selves through the material to an adja- the various record sizes are sorted
cent groove, causing the phenome- into both -sides -usable or one -side-
Fig. 2. After coating, steps are carried
non called "groove echo." Consistent usable categories. As might be im-
out wider clean -room conditions,
including inspection. performance of the lacquer under the
temperatures involved in cutting is
vital. Otherwise the cut will be noisy,
What Makes a Good Lacquer? A or the thin thread of material (the
blank lacquer disc is a rather impres- "swarf ") thrown up by the stylus will
sive product to behold. It is mirror - not separate cleanly from the groove.
finished (Fig. 2), solid and stiff, and Occasionally deposits of lacquer ma-
has an intriguing chemical aroma. The terial will bake right onto the stylus,
mirror qualities are not so important to scoring the groove. And, of course,
performance, although they do imply impurities or irregularities in the lac-
precision (and they give some indica- quer coating are verboten.
tion of the degree of polish the By now all these requirements are
finished groove walls will take on). The pretty much known and understood,
near -perfect flatness is. With many but now and then a bizarre problem
modern disc -cutting lathes the depth surfaces. For example, a cartridge
of the groove cut will of course vary if manufacturer recently drew my atten-
the recording surface rises and falls Fig. 4. Separating the metal master
tion to a fault in a test record's stereo from the lacquer disc.
beneath the cutting stylus. Since separation that he tentatively attrib-
deeper grooves must be spaced uted to the lacquer /cutting -stylus
further apart, it becomes difficult to agined, there is a lot of feedback from
interaction. Apparently the cutting sit-
decide on the appropriate average customers about the performance and
uation involved too much friction, consistency of the product, and this is
groove spacing, and on how many distorting the drive impulses from the
grooves (i.e., how long a program) the taken quite seriously.
cutter and altering the included angle
of the groove being cut.
The Lacquer's Fate. While we
were there, Capitol permitted us a look
How It's Done. However compli- at the Winchester pressing plant -a
cated it may be, the making of a blank real treat for me, since had never
I

lacquer disc certainly looks simple been admitted within the doors of
enough. It begins with a disc of such a facility before. Although amI

aluminum alloy, its surfaces prepared not as a rule an admirer of pressing

either by calendering or polishing, fol- plants, did manage to work up some
I

lowed by whatever cleansing and genuine sympathy for their problems,

chemical treatment the manfacturer considering that they're expected to
deems appropriate. Then comes the keep intact every nuance of a record-
lacquer, composed of a nitro- ing they won't even get a chance to
cellulose base with various (often hear until it's half way to the mass -
proprietary) additives. It is made up in production stage.
controlled batches, filtered, de- There is not enough space here for a
aerated, and then stored in special detailed description of the record -
tanks that keep its highly volatile con- making process (many of you are
tents stable until the moment of use. probably familiar with it anyway), but I

British recording pioneer Cecil can present some photographs of

Watts acquired a certain reputation sights that few in the outside world
Fig. 3. In curing tunnel, counter for eccentricity through his initial have seen first-hand. Figure 4 shows
aneasures airborne particles. scheme for coating his own recording the lacquer's fate. Here, in the
24 POPULAR ELECTRONICS

www.americanradiohistory.com
 ISOM
YOUR
0401Ce

Fig. .5. Metal mother is played and imperfections

are marked .for later removal through "nnierosargery."

operator's right hand, the lacquer is hole punched in the precise center of
being separated from a rather thick the groove spiral (Fig. 6). say "pre-
I

metal coating that has been built up cise" bemusedly, since too have had
I

on it through an electroplating proc- my share of off- center records. But

ess. The coating, called a "metal mas- from the look of this process, it
ter," is a negative of the lacquer. It will couldn't miss if performed properly.
in turn be electroplated to create a The presses that mold the vinyl rec- Mini-Scan TM
metal part that can actually be played ords are becoming automated more is the pocket
on a turntable (Fig. 5), so that flaws and more. The ones saw require little
I
scanner that
can be detected. When okay, it is itself more than an attendant to pick up the
plated, creating the die that will mold
works a week
stacks of finished discs and cart them
side one or side two of the record away. And that, after inspection (I on just 4
you'll ultimately have a chance to buy. hope) and packaging, is the last penlight cells.
Before it is mounted in the press, intended thing that happens to the
however, its edges will be trimmed offspring of the blank lacquer disc be- A breakthrough
and crimped to mold the contour of fore you have it in your own quivering
the record's edge. It will also have a
we call "mini-
and anticipatory hands.
miser circuitry"
makes it possible
... and it's
actually 21/2 to 5 times more
efficient than any other pocket
scanner we tested!* just 4 alkaline
penlight cells power it for a full
week, 8 hours a day, on a tough
50 -50 duty cycle (50% full volume,
50% squelched). And its perform-
ance is bred from our experience in
public safety two -way radio ... so it
also gives you the crispest, clearest
messages possible. Just $119.95
with built -in ferrite antenna
(batteries, crystals and optional
flexible antenna extra.)
*Test results gladly supplied
on request.

Johnso n TM

MINI-SCAN
.. the professional pocket scanner
Fig. Locating center hole.for stamper in col ccs
6. E. F. JOHNSON CO., WASECA, MINNESOTA 56093
spinning di..sc rnttil groove pattern appears /utionary.
.s
IN CANADA: A. C. SIMMONDS & SONS, LTD.
CIRCLE NO. 33 ON FREE INFORMATION CARD

SEPTEMBER 1975 25

www.americanradiohistory.com
 HIGHLIGHTS
International Digital Data Service Production -Line CCD
Western Union International has applied to the FCC for Fairchild Camera and Instrument Corp. is now produc-
permission to start a new international data communica- ing a charge- coupled memory device on a production -
tions service (IDDS). IDDS features simultaneous digi- line basis. The high- density CCD 450, a 1- kilobyte serial
tal transmission over both satellite and submarine cable storage element, is expected to be incorporated into ter-
links for greater assurance of continuous service. minals, video displays, and electronic switching net-
Equipment will sample incoming data signals up to 6000 works for data communications. It is organized as 1024
times each minute and select the preferred path at each words by 9 bits. OEM sample pricing is $90 in quantities
instant. Transmission rates of 50 to 9600 bits/second will of 1 to 10.
be used. A real -time link between New York and Paris
using IDDS has already been demonstrated.
Artificial Sky -Wave Propagation
RCA Demonstrates AM Stereo System Scientists at the Stanford Research Institute have dem-
RCA conducted live demonstrations of a proposed AM onstrated that a temporary bubble can be produced in
stereo transmitting system at the National Association of the ionosphere which reflects radio signals back to earth.
Broadcasters convention in Las Vegas. The system is The bubble is produced by heating the atmosphere with
said to be compatible with existing monophonic receiv- radio signals from a ground -based "heating transmitter."
ers, with the capability of multiplexing two discrete left The heating is based on principles similar to those em-
and right channels. Appropriate industry standards and ployed by microwave ovens. The bubble is typically
FCC approval would be necessary before AM stereo about 100 miles in diameter and 10 miles thick directly
broadcasts could become a reality. above the transmitter, and is invisible to the naked eye.
Space- charge irregularities within the bubble act as
Talking Computers radio reflectors. When the heating transmitter is turned
An expert in human and computer- synthesized speech off, the bubble disappears without a trace. The tech-
predicts that computers will someday be talking to man nique will be most useful for reflecting vhf signals, parti-
and helping him to do certain tasks. Dr. James Flanagan cularly those from public service radios and mobile radio
of Bell Labs says that talking laboratory computers can telephones. Existing 500 -kW shortwave transmitters
already read out stored information, verify the identity of can be used for heat sources.
a caller by checking his voice, and respond to simple
spoken commands. Computers speak in their own dis-
tinctive voices and accents, Dr. Flanagan says, which GE Marketing Transient Protector
they assemble from the speech resonances and rules of Asolid -state device will be introduced by GE to protect
syntax with which they are programmed. The voices can home entertainment equipment against potentially
exchange fairly complex information with a questioner. dangerous voltage spikes on ac power lines. The GE-
The machines' capacities are still restricted to recogniz- MOV'm is a voltage -sensitive metal -oxide varistor said to
ing single words from a limited vocabulary. One system be able to respond to line transients in 50 billionths of a
handles about 200 words, and another responds to second. It absorbs them and dissipates the energy in the
spoken digits. form of heat. Voltage spikes can be caused by the starting
of pumps, oil burners, fluorescent lights, as well as
CB Mobile Use lightning- induced effects. The device will not protect
The EIA's Citizens Radio Section reports that 1 in 5 equipment against a direct lightning hit, however. Volt-
long -haul trucks is equipped with CB radios and that 1 age transients are believed to be responsible for as many
out of every 28 American families (1 of 15 farm families) as one -half the component failures in solid -state televi-
uses the Citizens Band in one way or another, with over sion receivers and other home entertainment equip-
6% million CB radios now in use. Through the use of ment.
emergency channel 9, approximately 20 million emer-
gencies are said to be reported every year.
Transmitting Technique for "Ghosts"
Self- Healing Fuse RCA Broadcast Systems has demonstrated that circular
NASA has developed a self-healing fuse, primarily for polarization of television transmission virtually elimi-
use in remote locations. It is a very fast-acting, current - nates ghosting -an effect caused by reflected signals.
limiting device that provides current overload protection RCA says that the use of matching transmitting and
for vulnerable circuit elements. It then re- establishes the receiving antennas (both circularly polarized) provides
conduction path within a few milliseconds. It also per- "polarization discrimination" rejecting a reflected
forms as a fast -acting switch to clear transient overloads. signal. An application has been made to the FCC to
The fuse has a current-time curve almost identical to permit special antennas to be used for TV broadcasting.
that of an SCR. Life tests indicate at least 500 operations If approved, the use of such antennas (and special re-
before failure with fuse ratings from 4 to 40 amperes and ceiving antennas) should provide relief to viewers whose
50 to 100 volts dc. screens are haunted by "ghosts."

26 POPULAR ELECTRONICS

www.americanradiohistory.com
The new Sansui LM
Loudspeakers
sei
Convention
on its ears.
t
At the Convention of the Audio Engineering Society
in Los Angeles last May, Sansui demonstrated a new
concept in loudspeaker design.
The reception from these experts -chief engineers
of radio and TV stations, record procucers, recording
engineers and sales executives of audio companies -was
even more sensational than we ourselves expected.
And these are the reasons:
Unlike conventional speakers, the LM design incor-
LM 330 porates a multi -radiational tweeter device. High frequencies
CUT-A -WAY
instead of being lost through encapsulation, are diverted through
three special exponential horns and recovered into sound energy that
adds a breathtaking sense of ambience, and realism. The LM speakers also display
extremely stable and well- defined stereo images. At the same
time, both the transient response and efficiency of the system are
greatly increased. An extra large woofer assembly gives exceptionally
strong bass response ordinarily available only in much larger
and more expensive speakers.
Hear any of the 3 models available
at your nearest Sansui franchised
dealer. You never heard music so LM 330

alive before.
)))))
Multi- radiational
tweeter
SANSUI ELECTRONICS CORP.
Woodside, NewYork 11377 Gardena, California 90247
Slansu,
SANSUI ELECTRIC CO., LTD., Tokyo, Japan SANSUI AUDIO EUROPE S.A.,
Antwerp, Belgium ELECTRONIC DISTRIBUTORS (Canada) Vancouver 9, B.0
CIRCLE NO. 48 ON FREE INFORMATION CARD
SEPTEMBER 1975 27
www.americanradiohistory.com
 The better the training
the better you'll IN- CIRCUIT TRANSISTOR TESTER
TROUBLESHOOTER
COMPU-TRAINER VOM

SOLID -STATE
OSCILLOSCOPE
. r..
.n.

NTS /HEATH \
GR2000
Digital
Solid -State
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meter, and more. It's the kind of better equipment receive all home -study information by mail only.
that gets you better equipped for the electronics All Kits, lessons, and experiments are described in
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and the equipment
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32 POPULAR ELECTRONICS

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 Popular Electronics
SEPTEMBER, 1975

ITH stereo receiver prices rang- receiver to have a magnetic phono

ing from less than $200 to more input. This should be supplemented
by at least one high -level (Aux) input
than $1000, choosing a model around
which to build your hi -fi system is no
easy task. The difficulty lies in the wide
variety of features, functions, and per-
formance offered by the literally hun-
hat through which the audio output from
an eight -track cartridge tape player or
a TV receiver can be played.
The basic hi -fi receiver should also
dreds of receiver models available.
Obviously, a major consideration
when you are out shopping is what
you get for your money. If you have
Does have inputs and outputs for a tape re-
corder and a tape monitor switch for
simultaneous listening to
playback from the tape deck while re-
the

settled on a $400 to $500 receiver, for cording. The latter feature is impor-
example, you'll want to know what it
will give you that you can't obtain with Your tant even if you don't plan to use a tape
player because it protects your re-
a receiver selling at a lower price and
what you'll be missing that a costlier
ceiver from obsolescence. Further-
more, a variety of accessories -
receiver offers you.
We have studied the characteristics
of stereo receivers typical of each
price category. Bar graphs provide
Stereo including noise -reduction units, ac-
tive equalizers, and quadraphonic de-
coders and adapters-can be con-
nected to a receiver via its tape
at- a- glance performance expecta-
tions versus price. Obviously, there
are many other factors to consider
-operating and control features,
Receiver monitoring jacks. The accessories
permit you to update your system.
Common to every receiver are vol-
ume and tone controls. Each receiver
cosmetic styling, warranty policies, has at least one tone control for the
etc. -and we will touch on these also
in this report.

Features. A basic hi -fi system might

Dollar bass range and another for the treble.
Some of the more expensive receivers
have tone -control circuits that are
more elaborate, permitting more flex-
ibility in tailoring the sound to the
consist of a stereo receiver, two
speaker systems, and a record turnta-
ble. Naturally, one should expect the Buy? listener's preferences.
Almost all volume -control circuits

Hirsch-Houck Labs compares performance and price.

BY JULIAN D. HIRSCH

www.americanradiohistory.com
are supplemented by loudness com- $200 should be able to drive particularly audible as long as the am-
pensation systems that boost the low acoustic -suspension speaker systems plifier is operated within its design rat-
frequencies relative to the midrange of moderately low efficiency to a more ings.
and high frequencies when the vol- than comfortable volume level in your It is not our purpose to go into detail
ume level is reduced. Unfortunately, it listening room. Bear in mind that the here on frequency response, noise
has been our experience that fully 95% human ear requires a considerable in- level, input sensitivity, and so on.
of all such systems either do not have crease in power for a modest increase Though these are important consider-
the best response characteristics or in subjective volume level. A ten -fold ations, our experience suggests that
lack the provisions for matching the power increase will roughly double just about all modern receivers are
volume -control settings to the actual the apparent loudness. Fortunately, compatible with good hi -fi standards
volume of the sound. typical home listening levels can be in these characteristics.
Almost all stereo receivers have a obtained with surprisingly little audio One amplifier characteristic that is
headphone jack on the front panel for power -on the order of one watt or often overlooked is its phono overload
private listening. The rear apron usu- less. So, if you do not know how much level: the input signal amplitude at
ally contains output connectors for at power you need, play it safe and err on which the phono preamplifier stage
least two speaker systems (one per the high side. begins to distort significantly. With
channel). The recent FTC ruling regarding ad- some combinations of heavily re-
Most receivers that sell for more vertised amplifier power rating re- corded discs and high -output car-
than $200 feature interstation noise quires manufacturers to specify dis- tridges, it is possible for the phono
muting that removes the between - tortion level at any output power bet- preamp to severely distort if it is poorly
station hiss when tuning across the ween 0.25 watt and maximum at any designed. This one minor rating ap-
FM band. Since some muting circuits frequency limits specified by the man- pears to correlate very well with the
are more effective than others, it pays ufacturer. Furthermore, all channels overall quality of the amplifier.
to perform a listening test before you must be driven into the loads specified In the FM tuner section, sensitivity is
buy. by the manufacturer (usually 8 ohms). really not a very important specifica-
The great majority of receivers have The low and high frequency limits tion, especially in view of the way it is
at least one meter to aid in tuning. In most often set for hi -fi products are 20 presently defined. However, it does
lower- priced receivers, the meter and 20,000 Hz. give a clue to the over -all caliber of the
gives a broad indication when a sta- The rated distortion is the maximum tuner's performance. Much more im-
tion is properly tuned. Better receivers figure. One can expect that, at most portant is the signal input required to
might use a zero -center meter instead, frequencies and power levels, it will be achieve a listenable signal -to -noise
while still better models are likely to much lower than the published figure. (S /N) ratio. One might assume that
have both types of meters for unam- In fact, it is often less than a tenth of higher FM sensitivity (a lower number
biguous tuning indication. the receiver's rated distortion level. In of microvolts in the specifications)
Other control features, such as any event, the distortion should not be would go hand -in -hand with higher
rumble or hiss filters, microphone in-
puts, multiple- speaker- system switch-
TABLE: TABULATION OF SURVEY DATA (AVERAGE PERFORMANCE LEVEL)
ing, and the like, may or may not be 1

important to you. On higher -priced re-

ceivers, it is not unusual to find addi- PRICE RANGE (S)
tional input facilities, for a second
Survey Parameter 200-250 251 - 300 301 -350 351 -400 401 -450 451 -500 501 -600 600+
phono cartridge, one or two more
high -level sources, and a second tape
monitoring system. The last is nice to Power (watts) 15.4 16.8 23 40 46 53 49 79
have if you plan to use a tape deck and
some other accessory that would THD (%) 1.1 0.8 0.6 0.4 0.4 0.4 0.4 0.2
normally use the receiver's tape -
monitoring facilities. Phono Overload (mV) 77 88 102 117 87 144 152 210

Electrical Performance. Perhaps FM Sensitivity (pV) 2.5 2.3 2.1 1.8 1.9 1.8 1.9 1.7
the most advertised electrical specifi-
Mono FM THD ( %) 0.63 0.39 0.42 0.34 0.36 0.29 0.24 0.18
cation, and the one most closely re-
lated to price, is the receiver's output Stereo FM THD (%) 1.0 0.58 0.73 0.64 0.60 0.53 0.42 0.30
power. The greater the output power,
the larger and more expensive the Capture Ratio (dB) 2.7 2.5 2.1 1.6 1.8 1.7 1.5 1.5
output transistors, the larger the heat
sinks, and the larger the power trans- Alternate-Channel
former and filter capacitors. All of this Selectivity (dB) 51.2 51.2 55 65 66 68 78 83
costs money and adds to the sale price
of the receiver. Determining how Image Rejection (dB) 53.4 60 65 77 70 86 88 95
much power you need depends on
Average Price* $225 $268 $334 $368 $442 $488 $564 $714
your speaker systems, the size and
acoustical properties of your listening Receivers Surveyed 26 6 19 20 8 11 8 9
room, and your musical preferences.
Any receiver that costs more than "FalI, 1974

34 POPULAR ELECTRONICS

www.americanradiohistory.com
 loo o
"quieting" sensitivity (a higher dB
number). This is not necessarily true, 90

especially when comparing tuners

with roughly the same UHF sensitivity
rating. However, only the listener with
severe weak -signal problems is likely 70 0.7

to need all the sensitivity built into any

modern receiver. j
a
60
H
An excellent indicator of the quality D
O
of an FM tuner's front -end design is its 50

image rejection. A good image rejec-

d 40
tion figure is needed to eliminate inter- w
ference on certain frequencies. If you 4
1Y 0.3
w 30
are located near a busy airport, or on a á
flight path into or out of an airport, you 20 0.2
may already be aware of the problem
of interference. The only cure is a re-
ceiver with a higher (in dB) image re-
jection characteristic.
251 -300 301-350 351 -400 401 -450 451 -503 501-061 60 -
Another source of interference is PRICE RANGE -DOLLARS
alternate -channel signals from a
strong FM carrier 400 kHz removed
from a weaker signal you are trying to 1111111' SENSITIVITY /-1E)
í,

tune. This can happen in locations

=CAPTURE RATIO
very close to a powerful FM tansmitter.
(It is unlikely to occur if you are more
than a few miles from the nearest
transmitter.) Again, the best cure is
high alternate -channel selectivity (the
higher the dB number, the better),
which is a function of the receiver's -f
i

amplifier design.
Many manufacturers emphasize the
capture ratio of their receivers. This is
an indication of how completely the
stronger of two signals on the same
frequency will take over (or capture)
and prevent the weaker from being
heard. A low number is better. Some
receivers have a capture ratio as low
as dB. This means that with a signal
1
D-250 251- 500 301 -350 351 -400 401 -450 45 -500 501 -600 601+
level difference of only dB, the

-
1 PRICE RANGE -DOLLARS

stronger will suppress the weaker by

30 dB, and if the signals are more than
1 dB apart, it is possible that the
ineNo
weaker will not be heard at all. In most
geographical areas, it is unlikely that =STER°_o

two receivable signals will occupy the °.Q'

same channel. 0.0

The greater significance of capture
ratio is in its ability- together with AM 0.7
rejection, to which it is somewhat
related -to reduce multipath distor- oo.v
z
tion. This distortion can deteriorate
the quality of stereo FM reception. It
occurs in many urban and suburban °4
locations, where signals are received
from stations via several different 0.31

paths. The direct signal arrives first,

followed by one or more delayed sig-
nals reflected from obstacles in the 0.1
surrounding terrain.The time differ-
ences between the arrivals of the -450 -500 -600 601+
00-250 25 - OC 301-35C 35 -400 401 35 501
signals cause severe cancellations PRICE RANGE-DOLLARS
and amplitude modulation of the re-
SEPTEMBER 1975 35

www.americanradiohistory.com
 ceived signal. The ultimate solution to
severe multipath distortion is a direc- TABLE 2: COMPARISON OF MEASURED RECEIVER PERFORMANCE

tional antenna, but a receiver with a

good capture ratio will tend to dis- AND NAME AND MODEL
criminate against the weaker portions
Rotel Sherwood Sylvania
of the multiple signal and reduce the
RX -402 S -7110 RS -4744
distortion.
The distortion imparted to signals
Price (S) 350 290 230 400
by the FM tuner section of the receiver
is a function of the amplitude and Power (W) 23/25/25* 16.8/25/25 15.4/17/17** 40/60/60
phase characteristics of the -f am-
i

plifier and detector. Elaborate and ex- THD ( %) 0.6/0.5/0.06 0.8/0.5/0.6 1.1/0.9/0.1** 0.4/0.25/0.13
pensive components are needed to
provide the nearly ideal characteris- Phono
tics that minimize distortion in the Overload (mV) 102/110/100 88/85/87 77/90/88 117/NA/82
finest tuner designs. In stereo, distor-
tion problems are compounded be- FM Sensi-
cause the stereo demodulator adds tivity (NV) 2.1/1.9/1.8 2.3/2.0/1.8 1.8/2.0/2.1 1.8/1.8/2.0
distortion of its own. As a result, stereo
Capture
distortion is almost always greater (by Ratio (dB) 2.1/1.0/0.7 2.5/2.0/3.3 2.7/1.5/0.7 1.6/1.5/0.7
an average of twice as much) than
mono distortion. Selectivity (dB) 55/60/63 51/70/71 51/60/61 65/55/51

Performance vs Cost Study. The Image

performance categories we analyzed Rejection (dB) 60/60/70 60/60/53 53/60/51 77/53/56
in our study were: output power per
channel into 8 -ohm loads with both Mono THD ( %) 0.42/0.20/0.12 0.39/0.20/0.65 0.63/0.44/0.22 0.34/0.40/0.27
channels driven over the audio range
Stereo THD ( %) 0.73/0.40/0.48 0.58/NA/0.45 1.0/0.6/0.28 0.64/0.40/0.63
(usually but not always 20 to 20,000
Hz); maximum THD at full power
within the frequency range; phono 'Three-figure entries in each column are interpreted, left to right, as follows: Averaged value
input overload signal level; FM sen- from Table 1 /manufacturer specification /Hirsch -Houck Labs measurement. NA means in-
sitivity (IHF usable); FM distortion in formation not available.
both mono and stereo; FM capture **Specified at 40 to 20,000 Hz. All others 20 to 20,000 Hz
ratio; FM alternate -channel selectiv-
ity; and FM image rejection. There are
many other specifications that could
have been included, but not all were
available for a sufficient number of re- spread in performance within each of with price, except for a drop in the
ceivers to provide meaningful results. the arbitrary price ranges we selected, $401 to $450 range, which may reflect
However, we consider the specifica- you can expect some overlap in per- an inadequate sample lot. Even the
tions selected to give a good picture of formance. The best receivers in one lowest -priced receivers can typically
the overall quality of a receiver's am- range may well be superior to the low- handle 80 mV (the higher the mV the
plifier and FM tuner sections. est ranks in the next higher range. better) without overloading. Only a
The performance ratings were taken The results of the study are tabu- few years ago, such a high overload
directly from the figures published by lated in Table 1 and graphically via the level was available in a very few of the
the various manufacturers. Some bar graphs. The graphs clearly illus- highest -priced receivers.
people might question this approach, trate the relationship of each perfor- FM sensitivity improves slightly with
but it has been our experience that, for mance rating to price. Starting with price. This is partially because today's
the most part, most manufacturers the lowest -priced receivers, audio receivers approach the theoretical
honestly and even conservatively rate power gradually increases with in- limit, which is variously stated to be
their receivers. A receiver's perfor- creasing price, although not signifi- between 1.5 and 1.8 LA/. Since it is rela-
mance will often surpass its published cantly until the $450 point. The most tively easy to achieve a 2.5 -L1V sensitiv-
ratings by a comfortable margin. Even notable increment comes in the most ity in a low- priced receiver, the gap
when it fails to meet a particular expensive ($600 -plus) category, between the least and most expensive
specification, the difference is rarely where the average power rating of al- models is slight. Although the quieting
serious. most 80 watts /channel is at least 50 %. sensitivity for a 50 -dB S/N ratio is more
The objective of our survey was to greater than in any of the lower- priced meaningful, this information wasn't
determine the average level of per- groups. It is striking to note the rapid available for a sufficient number of the
formance offered in each price range. drop in rated distortion with increase receivers surveyed to be included in
If you want to know which receiver is in price and the leveling -off at the $350 our calculations. Our experience with
inferior or superior to the average, you mark, above which there is no sig- actual receiver performance indicates
should examine manufacturer spec nificant reduction in distortion until that there are appreciable differences
sheets or the listings in the STEREO the $600-plus point is reached. among receivers with respect to quiet-
DIRECTORY& BUYING GUIDE. Due to the Phono overload level rises steadily ing sensitivity, especially when weak -
36 POPULAR ELECTRONICS

www.americanradiohistory.com
signal FM reception is required.
Naturally, the more expensive receiv-
ers tend to be better in quieting sen-
1001

90
_ = ALTERNATE CHANNEL SE1- ECTIVITY

=IMAGE REJECTION
sitivity. In most strong -signal areas, 80
the differences in quieting, or ultimate
S/N ration, are usually difficult to de- 70

tect without critical listening.

Capture ratio seems to follow sen- 6
.
sitivity as price goes up. But here, too,
the differences are slight. FM distor- 50
tion, like audio distortion, decreases
40
steadily with increasing price, with the
major improvements taking place be-
30
tween $200 and $300 and again above
$500. Selectivity and image rejection
20
go hand in hand, although they are

i
related to completely different parts of 101

the tuner circuitry, with little change

up to the $301 to $350 range, where a L
:00 -250 251 -300 301 -350 351 -.00 401 -450 451 -500 501 -600 601+
steady and significant improvement PRICE RANGE -DOLLARS
occurs all the way to the most expen-
sive receivers.
Receivers often surpass their pub-
24C
lished specifications in many re-
spects. To illustrate this, we have re- 22C

viewed our recent laboratory tests and

20C
have chosen representative receiver
models in each of the four lowest - 17C

priced ranges in our survey. There

16C
wasn't sufficient choice of receivers in
the high -priced range, since most 140

$500 -plus models tested in the recent 0

12C
past have been 4- channel models. As
it happens, the receivers we selected IOC

all surpassed many of their published

80
ratings and were above the average
specifications in their respective price 6C

groups.
4C

Conclusions. The most interesting 2G

result (which we weren't entirely pre-

pared for) of our survey was that the L2cn -250 251 -300 301 -350 351 -400 401 -450 451 -5C0 503 -630 501+
PRICE RANGE- DCLLARS
greatest incremental improvement for
the extra cost can be obtained by
going to the $351 to $400 range. It is in 28
AVERAGE PRICE OF EA<:H
this price range that all facets of re- 26
6225 RANGE SHOWN ABOVE BAR

ceiver performance seem to be op-

timum. Lower -priced receivers are 24

less advanced in their performance, to 22

say nothing of control feature limita- 20

§334
tions, while a worthwhile improve-
ment would probably require a jump to 17

over $500. 16

There is a danger in reading too 2 14

much into the above because of the ó
overlap between ranges and the wide w 12

variations within each range among 2 10

receivers from different manufactur- Z e a42 $s6a

ers. Of course, there is the matter of
e
rla
$267
features and control flexibility, which, 6

although they are not among the tabu- 4

lated parameters, are the major differ-

2
ences between models in adjacent
price ranges where electrical perfor- 0
20,-250 251-300 301-260 351-400 4C1- 450 411-500 -600 6171+

mance differs very little. Q PRICE RANGE- DOLLARS

SEPTEMBER 1975 37

www.americanradiohistory.com
 r1111111111111 Photo nt le'f't shows switches
HOW TO ADD POP
rruututed (III tor of rnlcrrlrttur

FUNCTIONS TO Checkout and Use. Turn on the cal-

culator and push the numeral keys at
SIMPLE HAND random to just fill the display. Allow
the display to remain undisturbed for
about 60 seconds. If the battery -saver
CALCULATORS feature is operational, the seven most
significant figures in the display will
blank out. Depress the key: the
If it contains the right IC, same random number should in-
you can turn your calculator stantly reappear in the display. You
into a more useful one can depress any of the arithmetic -
function keys to restore the display in
at little extra cost this manner. Alternatively, you can use
an externally mounted switch to re-
BY DONALD SHAPIRO
store the display: label this switch DR,
for display recall.
CALCULATOR manufacturers proach to replace the keyboard in an Depress keys C, 1, 2, and 3. The dis-
often stock just one type of IC inexpensive calculator with one that play should now have the number 123
and use it in a range of units-from a has extra keys to accommodate the showing. Now. depress %; the display
simple four- banger to one having extra functions. It would be far more should now indicate 1.23. (Any time
memory, constant, percent, and practical to mount several miniature
battery -saver functions. So it is possi- pushbutton switches on the outside of
ble that your inexpensive calculator the calculator's case for the constant,
can be modified to include the extra storage memory, and percent func-
functions. We say possible because if tions and make one minor printed cir-
the "bare- bones" MM5737 is used. cuit board change to activate the
there are no extra functions available. battery -saver feature. The photos
With an MM5738 IC, however, there show how a Novus Model 850 cal-
may be one or more extra functions culator was modified to take advan-
available. The basic arithmetic func- tage of the constant (K) and memory -
tions will be intact but the extra func- store (MS) and memory -recall (MR)
tions are inoperative. In the latter case, functions that were operational in its
the IC manufacturer usually indicates MM5738 IC.
an inoperative function by marking To perform this type of modifica-
the case near the pin with a dot. tion, the calculator case must be dis-
A simple test can be performed from assembled to allow access to the bot-
the calculator keyboard to determine tom of the printed circuit board and
if the extra functions are available. provide working room for mounting .-i rot rrryr rt'irr's it, buttery well
This test is based on the ability of the the extra -function switches on the top wr they do trot interfere.
MM5738 IC to perform repeated of the case. First, isolate pin 13 of the
squares. Press: 3, x, =, =. An answer IC from the rest of the circuit by care- the % key is operated, the calculator
of 9 indicates that no modifications fully cutting through the copper foil automatically multiplies the displayed
are possible, but if the answer is 81, near the IC pin: this will activate the number by 0.01.)
extra functions can be used. battery -saver feature. Then, carefully To check the memory function, feed
drill holes for and mount the switches. in the keystrokes in the following
Modifying the Calculator. It would Now, referring to the schematic order: C, 2, 3, = (a 6 should now be
be an unrealistically expensive ap- diagram, solder lengths of hookup displayed). MS, 3, - 5, = (15 should
,

wire to the extra -function IC pins that now be displayed), x, MR, =. The
are operational. Route the wires along answer displayed at the last = key-
the bottom of the board, and reas- stroke should be 90.
semble the case, with thew res exiting Finally, check out the constant func-
through the battery compartment tion for both the A and _ functions.
cutout. Solder the free ends of the Start by pressing C. Then turn on K
BOTTOM
18 VIEW 7
wires to the appropriate switch lugs. and press 2, 2, = K, K, K, K. The
, ,

*NORMALLY -OPEN MINI 17

MM5738 Cut a shallow groove in the case, answer displayed, if the constant func-
PUSHBUTTON TYPES 16 9 making it just deep enough to ac- tion is working properly, should be 64.
15 10
commodate the wires when the Hit C, 8, 8, 8, 2, =, K, K; the display
battery- compartment cover is in should now read 111. The constant
place. Then neatly arrange the wires in function works on only the x and
the battery well so that they will not be functions. The number used as the
in the way of the battery. Plug the bat- constant in either case is the one fed
tery into its connector, set it into the into the calculator after the arithmetic
Where to acld switches to IC. well, and replace the well cover. command is entered.
38 POPULAR ELECTRONICS

www.americanradiohistory.com
 BUILD A

I ¡ICI I-PERFOR
CD -4 DEMODULATOR
Low -cost add-on unit for playing discrete 4-channel discs.
BY LOUIS DORREN

THE Compatible Discrete 4 -chan- low -cost demodulator described here. from the combined night and left sig-
nel sound system, called CD -4, With the demodulator plugged into nals, separate 30-kHz subcarriers are
permits four fully separate channels of your receiver and a CD -4 cartridge on used. One carrier contains the differ-
sound to be reproduced, starting with your record player, you will be able to ence of left -front and left -back signals
discrete channel information incorpo- play all types of 4- channel discs in- and the other contains the difference
rated right into the record groove. This cluding discrete. of the right -front and right -back sig-
contrasts with SQ" or QS matrix nals. By mixing the signals in an ap-
4- channel sound, where channel in- CD-4 Operation. The CD -4 system propriate resistive network, each of
formation is encoded. was designed to utilize the standard the originally recorded channels can
Some four-channel receivers today V- shaped record groove to assure be extracted, resulting in the four dis-
are akin to multiple -speed record compatibility of quadraphonic disc cretely different channels originally
players that play 33 -1/3 or 45 rpm recordings with conventional stereo recorded.
discs. The receivers can quite often and mono playing equipment. So, all While the CD -4 system is basically
handle information from either dis- of the information contained in the very simple, special techniques de-
crete or matrix discs. There are many four signal channels had to be com- veloped to minimize signal degrada-
4- channel receivers, however, that bined to physically fit on the two walls tion require a complex demodulator
only have a CD -4 input jack for adding of the record groove. In the process, circuit design. Pre -emphasizing the
a demodulator that's needed to play the left -front and left -back signals are carrier is one such technique. Unlike
CD -4 discs (which includes RCA's combined and impressed on one wall, the case in standard FM broadcasting,
"Quadradiscs," among other labels), while the right -front and right -back the pre- emphasized signal is fre-
while incorporating decoding circuits signals are combined and impressed quency modulated from 0 to 630 Hz
for SQ and /or QS matrix discs. If this is on the other wall of the record groove. and from 6000 to 15,000 Hz, and audio
the case with your receiver, you will To facilitate separation (demodula- information between these two ranges
want to build the high -performance, tion) of the front and back channels is phase modulated (PM) to provide a
SEPTEMBER 1975 39

www.americanradiohistory.com
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40 POPULAR ELECTRONICS

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 better signal -to -noise (S /N) ratio as output relies on precise tracking of the
DEMODULATOR PARTS LIST well as other advantages from the 30 -kHz carrier that is present -along
standpoint of higher level- capacity to with the standard stereo infor-
BPFI,BPF2 -30 -kHz bandpass filter the overall system. mation -even the smallest variation in
(EUL- BPF006)
C I,C8,C 13,C 16,C 19,C22,C25,C28,C39, Audio level compression is also ap- turntable speed can significantly de-
C40, C43, C44, C45, C57, C61- 3,3 -pF, plied in the modulation technique. It grade the overall signal. Hence the
25 -volt electrolytic capacitor reduces the harmonic distortion of need for the PLL. The other reason
C2, C46- 220 -pF, 25-volt electrolytic ca-
pacitor second -, third -, and fourth -order why the PLL is needed is the very wide
C3, C47- 0.0047 -NF capacitor components. In some cases, it even deviation of the 30-kHz subcarriers,
C4, C48- 0.002 -NF capacitor reduces noise. which presents extreme difficulties for
C5, C49, C64, C76- 0,47 -NF capacitor
C6, C50-0.033 -µF capacitor low- distortion demodulation to other
C7, C51, C59, C73, C74, C75-0,01 -µF How It Works. Each specialized IC types of FM detectors.
capacitor Whenever an input signal differing
C9, C52-0.0027 -µF capacitor used in this project contains all of the
CIO, C36, C53, C70- 0.0031 -pF capacitor subsystems required for demodulat- from the 30-kHz free -running loop fre-
C 11, C14. C17, C20-0.0062 -NF capacitor ing one pair of channels. These in- quency is applied to the phase detec-
C12, C15, C18, C21- 820 -pF capacitor
C23, C38, C55, C68- 960 -pF capacitor clude a phono preamplifier to in- tor, a corresponding error voltage is
C24, C37, C56, C69- 0.0039 -µF capacitor crease signal levels from the phono produced in the loop filter (RC net-
C26. C35, C58. C71- 0.0068 -µF capacitor cartridge; a high -gain limiter FM de- works R12 /C6 and R69/C50) that is set
C27, C60- 0.0072-µF capacitor
C29, C30, C41, C42, C54, C62. C63 tector; a phase -locked -loop (PLL) FM to the bandwidths of the PLL's. This
-100 -pF capacitor detector; and a high -speed carrier output information causes the vco to
C31, C65- 0.0022-µF capacitor
C32, C66-0,68 -pF capacitor dropout cancellation circuit. Also pre- swing toward the input frequency, re-
C33, C67- 4,7 -pF, 25-volt electrolytic ca- sent on -chip are an FM /PM /FM am- ducing the error voltage until the vco
pacitor plifier, mid- and high -band audio ex- and input signal frequencies are
C34, C72-33 -pF capacitor
CRI to CR4 -Diode (IN914 or similar) panders, resistive combining output equal. At this point, the PLL is
DSI- Low- current red LED (20 -mA networks (true matrix), output buffer "locked" and remains so in spite of
max.) minor input variations. Pins 17 of IC1
ICI, IC2- Demodulator (QSI -5022) amplifiers, a drive circuit for a quad-
LI. L2- 100 -mH inductor raphonic indicator LED, a complete and IC2 connect to timing capacitors
QI to Q8- Transistor (2N5210 or similar) power -supply regulator, and automat- C9 and C52 of the vco's while pins 16
The following resistors are 1/2 watt, 10%
tolerance: ic changer transient muting circuits. connect to potentiometers R16 and
RI, R24. R28, R32, R36, R58, R97, By combining two IC's, with appro- R72 that are used to set the center
R98-47,000 ohms priate filters and other related compo- frequency of the vco's.
R2. R18, R59- 100.000 ohms
R3, R46, R60, R90- 10,000 ohms nents, in a single system (see Fig. 1),
R4. R14. R61- 150,000 ohms we can obtain a CD -4 demodulator of
R5, R6, R7, R20. R45, R62, R63. R64, advanced design.
R75. R88. R101. RI02- 15,000 ohms
R8, RI I, R13, R65, R68, R70 -2200 ohms The input signal from a magnetic
RIO, R67, R99, R100-20 ohms phono cartridge is applied to pins 26
R12, R69, R77, R78-330 ohms
R15, R71 -6800 ohms of IC1 and IC2. Equalization networks YND
Ds
R17, R40, R73, R83 -8200 ohms between pins 24 and 25 of each inte-
R I9, R74 -7500 ohms grated circuit shape the frequency re- POWER SUPPLY PARTS LIST
R21, R22, R23. R25, R26, R29, R30, R3I,
R33, R34, R35, R37, R38. R39, R41, sponses of the amplifiers to produce
C I- 2000 -pF,25 -volt electrolytic capac-
itor
R43, R47, R50, R51. R52, R53, R80, the RIAA curve characteristic. In the C2, C3- 50 -pF, 25-volt electrolytic capac-
R81, R82, R84, R86, R89, R93, R94, case of a semiconductor phono car- itor
R95. R96 -4700 ohms D1 to D4 -Diode (IN4001 or similar)
R27 -Not used tridge input, the equalization is flat for FI -1/2- ampere fuse
R42, R85- 27,000 ohms the preamplifier. The preamplifier has QI -40406 (RCA) or similar transistor
R44, R48, R87, R91-220,000 ohms RI-330-ohm. 'h -watt resistor
R49, R92-3300 ohms both inverting and non -inverting out- S1 -Spst switch
R54. R57-470,000 ohms puts. The inverting network is used in TI -15 -volt, 300-mA transformer
R55, R56-1800 ohms one IC and the noninverting network is Z1 -15 -volt, 500 -mW zener diode (HEP
R76. R79-1000 ohms Z0225 or similar)
R9. R66-500 -ohm trimmer potentiometer used in the other IC because the Misc. -Printed circuit board; spacers; fuse
R16, R72 -5000 -ohm trimmer potentiom- semiconductor outputs are out -of- holder; line cord; rubber grommets;
eter phase with each other and only one grounding lug; hookup wire; machine
S1-5-pole. double -throw switch hardware: solder; etc.
S2 -Spdt switch must be inverted before the signal is
Misc.- Printed circuit board; suitable passed to the rest of the demodulating Fig. 2. Conventional power
chassis (see text); phono jacks for inputs supply uses zener regulation.
and outputs (6); spacers or plastic stand- system.
offs: 28 -pin IC socket or Molex Solder - The outputs of the preamps (pins
cons (optional); hookup wire; machine 23) go through 30 -kHz bandpass fil-
hardware; solder; etc. The audio output signals from the
Note-The following are available from ters that isolate the subcarriers and
Southwest Technical Products Corp. eliminate unwanted signals from the IC's, at pins 15, are coupled to 15 -kHz
219 West Rhapsody. San Antonio, low -pass emitter -follower filters and
78216: BPFI, BPF2, ICI. 1C2, L1, and main, or audio, channels. The filter
L2 for $24.50; etched and drilled power outputs go to the circuit limiters (pins the networks required in the sub -
supply and demodulator printed circuit 22). Then, pins 21 serve as the bypas- channel systems for delay equaliza-
boards for $13.00: complete kit of parts, tion (see small dashed boxes to the
including chassis and power supply, for ses for the limiter stages.
$50.00. The outputs from the limiters (inside right of the IC's). The vco's also feed
Fig.1. Schematic, left, shows the IC's) feed the phase detectors of back to the phase detectors to yield a
how two IC's, with added the PLL's. locked condition when the carrier is
components make up circuit. Because the fidelity of the 4- channel present. The outputs of the limiters are

SEPTEMBER 1975 41

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11-S1C 1. S-S1D->'l-1> ['DC, C-LF OUT, H-S1.4-1, N-S1C-2, D-RF OUT, J-Sl.a _'. P-S/C-1,
E-LB OCT, li-SIB-1, Q-S1D-1, L"-51E-S. .Iltnrpers frolli i to I, d to ?, ; tu .;, ulul i to ,'.
42 POPULAR ELECTRONICS

www.americanradiohistory.com
also passed to the carrier -level (C.L.)
detectors, which consist of quadra-
ture phase detectors. These are fed
from the limiters, vco's, and carrier
dropout cancellation circuits. When C -#- -DFQ

-
fND'il-
the signal is locked, the quadrature
detectors sense the 900 quadrature
+ISV
differences between the vco and input Fig... Etching and +-1 RI
signals, turning on 4- channel LED F- --01-63
drilling guide (above) ca AC
DS1 and allowing the audio from the and component layout oI
subchannel detectors to pass to the for power supply (right)
expanders.
Pins 14 of each IC can be used to
select between 4- channel and positive -voltage inputs for the IC's, LED indicator DS1 mount on the front
4- channel /auto operation as they are while pins 6 and 7 are the audio out- panel. Use a small rubber grommet in
grounded or left floating, respectively, puts. These outputs are fed to the final the hole for the LED. Mount the power
via S2. The output circuits that drive 15 -kHz emitter -follower low -pass fil- transformer and fuse holder, side by
DS1, accessed through pins 13 on the ters. side, to the floor of the chassis, locat-
IC's, provide a current sink of no more The power supply for the demod- ing them to one side and near the rear
than 20 mA. So, it is important that you ulator is shown schematically in Fig. 2. panel.
use a low- current LED for DS1. It is quite conventional in design, em- Solder lengths of hookup wire to
Pins 12 are the signal inputs to the ploying bridge (D1 through D4) recti- both boards to facilitate interconnec-
audio shaping networks in the subcar- fication, zener -diode (Z1) regulation, tions. Keep tabs on where the free
rier system. They are fed from the and a series -pass transistor (Q1). end of each wire is to terminate. Im-
15 -kHz low -pass filter and delay net- mediately interconnect the two circuit
works. Audio- frequency shaping net- Construction. Owing to the com- board assemblies and the power
works for FM /PM /FM equalization are plexity of the circuit that makes up the transformer with the power supply
connected to the IC's via pins 11 and demodulator, printed circuit board board. Mount the boards on the floor
12. Pins 11 also drive the expander assembly is highly recommended. An of the chassis with machine hardware
controls and audio inputs. Pins 2 and actual -size etching and drilling guide and spacers or plastic standoffs.
5 are used for the expander time - for the pc board is shown in Fig. 3, Then, referring back to Fig. 1, connect
constant controls, while pins 1, 3, 4, along with the component placement and solder the free ends of the wires to
and 28 serve as audio and control in- diagram shown from foil side. the appropriate jacks, switches, and
puts for the expanders. Start assembly by installing and LED. (Note: Before completing the
The outputs from the expanders soldering into place on the board the wiring, refer to the Test Procedure out-
feed the resistive combining networks resistors, capacitors, and inductors lined below.)
(true matrices), which are also fed by (coils). Follow with the diodes, transis-
the subsystem amplifier and automat- tors, and bandpass filters. Pay careful Test Procedure. Temporarily con-
ic changer muting circuits. Pins 10 are attention to the polarities of the elec- nect a milliammeter between the posi-
the control inputs for the automatic trolytic capacitors and diodes and the tive terminal of the power supply and
changer muting detectors, while pins basing of the transistors. the positive voltage input of the de-
9 are the audio inputs and bias termi- Last to be installed on the pc board modulator board. Remove DS1 from
nals for the amplifiers. Pins 8 are the should be the two IC's. You can di- the circuit. Plug the line cord into an
rectly mount the IC's and solder their ac outlet. Turn on the power and ob-
pins to the pads on the board, or you serve the meter indication. The cur-
"CD-4 HANDBOOK" can install sockets or Molex rent drain should be less than 100 mA.
AVAILABLE Soldercons' into which the IC's can If you obtain a higher reading, a short
be plugged. circuit exists and must be corrected.
A comprehensive 28-page "CD -4 Hand- Next, wire the power supply board. In this event, turn off the power and
book" available from Matsushita Electric
(The etching and drilling and compo- unplug the line cord from the ac sock-
Corp. explains what quadraphonic sound
nent placement guides for this subas- et. Carefully examine all your wiring
is all about. It especially explains how the
CD -4 format differs from the matrixed sembly are shown in Fig. 4.) Again, pay and soldering, particularly around the
disc formats. Topics included in the book- careful attention to diode and elec- closely spaced pads to which the IC
let include a quick look at the disc from trolytic capacitor polarities and the pins or sockets are soldered.
Thomas Edison to the present; how quad- transistor's basing. Once you obtain a normal current
raphonic systems work; information on The prototype of the CD -4 demod- reading, connect a voltmeter from pin
quadraphonic FM broadcasts; a roster of ulator was mounted in a 9 "D x 7 "W x 27 of each IC and ground. You should
CD -4 equipment manufacturers; a com- 2 "H(23 x 18 x 5.1 -cm) U- shaped metal obtain a 5.8 -volt reading in both cases.
plete list of CD -4 Quadradisc artists and
chassis. The six INPUT and OUTPUT Turn off the power, disconnect the line
albums; suggested speaker placement for
the optimum listening environment; etc.
jacks, Si, S2, and a grounding lug cord, remove the milliammeter from
To Obtain a copy of the "CD -4 Hand- mount on the rear panel. A hole drilled the circuit. Then wire the positive
book," write to: Matusushita Electric through this panel through which the leads from the power supply and de-
Corp. of America, Panasonic Way, Sec-
1
line cord exits must be rubber grom- modulator boards together and the
aucus, NJ 07094 or JVC America, Inc., met lined. LED back into the circuit.
50-35 56 Road, Maspeth, NY 11378. The POWER switch and 4- CHANNEL Connect a 4- channel (CD -4) phono

SEPTEMBER 1975 43

www.americanradiohistory.com
 the next issue of the
magazine that gives
you the most exciting
E C
build -it- yourself EXPER
projects anywhere.
You can always count on ELECTRONIC EXPERI-
MENTER'S HANDBOOK. Published each year by the
editors of Popular Electronics, it's the one publication
that helps you get it together ... with a score of
YOU CAN build -it- yourself projects.
The all -new 1976 edition goes on sale
RESERVE nationally September 18, 1975.
It will again be packed with features and
YOUR COPY NOW AT articles and complete lab- tested instruc-
tions that are sure to guarantee success-
THE SPECIAL ful hours and months of mind absorbing
projects for fun and practicality.
MONEY -SAVING This offer is being made to readers of
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OF ONLY $1.00 order price $1.85. You can reserve your
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vation Form and returning it promptly along
with your remittance. The 1976 ELECTRONIC
EXPERIMENTER'S HANDBOOK will be mailed to
you on or before publication date from first- off -the-
press copies.

®®Electronic Experimenter's Handbook

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PRE -PUBLICATION ®® Enclosed is $1.00 (outside U.S.A. $2.00). Please
RESERVATION reserve my copy of the 1976 ELECTRONIC EXPERI-
MENTER'S HANDBOOK at this special pre -publication
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Residents of Cal., Col., Fla., III., Mich., Mo., N.Y. State, D.C. and Tex. add applicable sales tax.
44 POPULAR ELECTRONICS

www.americanradiohistory.com
cartridge to the demodulator via the
audio input jacks. Make certain that

THE
switch Si is set tO SEMICONDUCTOR or
MAGNETIC, according to the type of
cartridge you are using. Use the setup
tone provided on a CD -4 test record
for an audio signal at all four outputs
from the demodulator. (A CD -4 test re-
cord can be obtained for $5.00 from
the source given in the Parts List.) The
absolute levels of the individual chan-
nel outputs are not critical at this
point, but the left -front level should be
the same as the left -back level and the
M ISSING LINK
right -front level should be the same as
the right -back level.
When the system is properly detect-
ing, DS1 will glow brightly. If it glows
dimly or does not glow at all, one or
both of the phase-locked loops may be
too far out of adjustment. In thus case,
any of the following procedures can
be used to set the PLL's on the correct
30-kHz frequency:
1. With the cartridge stylus tracking
the setup band of the test record, ad-
just the vco's via R16 and R72. Adjust
first one vco until the LED glows, then
adjust the other until the LED glows at
maximum brightness. Because of the
high -level subcarrier modulation, you
should now hear severe signal distor-
tion. Now, adjust R16 and R72 for
minimum audible distortion.
2. Using an accurate 30 -kHz sine -
wave source, feed this signal to pin 22
of ¡Cl through a 1000 -pF capacitor.
Adjust the vco's center frequency via
R16 until the LED glows. Then couple
the test signal to pin 22 of 1C2 and
adjust the other vco via R72 for max-
imum brightness.
3. Connect a high- impedance fre-
quency counter to pin 16 of ¡C1 and
ground and adjust the vco to 30 kHz
(R16) without an input signal. Repeat
the procedure for 1C2 (R72).
Any of the above procedures will
work successfully, but be sure that The first five seconds of every
you adjust the center frequency of Maxel UD cassette cleans your recorder heads.
I

both IC's.
Once the vco's have been properly Another Maxell exclusive.
adjusted, use the test record to check The leader in our UD cassettes 't's on bcth ends of all Maxell Ultra
out the entire demodulator. Carefully sweeps dust and debris off your recorder Dynamic cassettes. Its another reason you
listen to the rear channels and adjust heads before they can foul -up a record- con record the very best sounds (both
separation controls for minimum vol- ing. And it sweeps gently, with no damag- high and low) your equipment produces,
ing abrasives to ruin your equipment. without tracking dust all over your music.
ume level of these channels. Once
Our head -cleaning leader is also Maxel Corporation of America,
these adjustments have been made, I

calibrated, so you can use it to cue your Moonachie, New Jersey07074.Also avail-
they do not have to be touched again
unless you decide to replace the
phono cartridge.
recordings. able it Canada.
maxell
For processional recordings
The CD -4 demodulator is now ready at home.
to use. Fasten the case cover to the CIRCLE N0. 35 ON TREE INFORMATION CARO

chassis, and connect the demodulator

into your 4- channel hi -fi system.
SEPTEMBER 1975 45

www.americanradiohistory.com
 Communications
Engineering

Automatic Missile &

Control Spacecraft
Engineering Guidance

Radar &
Sonar Digital Industrial
Engineering Communications Electronics

Microwave Satellite
Engineering Communications

Cable Nuclear Special Programs

Television Instrumentation for Electronic
Engineering & Control Engineers

46 PORI LAR E!LECTRONICS

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SEPTEMBER 1975 49

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 HAVE you ever tackled a digi- a= b =c =1, a =c =1 and b =0, a =0 and
tal project with vim
design
and vigor -only to find yourself en-
KARNAUGH b =c =1, or a =b =0 and c =1. How can
we manufacture the digital logic in-
tangled in a morass of logic ones and side the box from this specification?
zeros and a "this goes up, and that
goes down" nightmare? If you have,
MAPS One possible answer is to be
methodical. A person unfamiliar with
don't despair. There is a much neater, map techniques -but very method-
much simpler method than the brute ical-might reason in the following
force approach. This article provides FOR FAST way.
a coherent approach to digital de- The output function f(a,b,c) is
sign. The method is not a substitute logic one whenever a= b =c =1. An
for intuition and practical seat-of-
the -pants experimentation, but a tool
DIGITAL AND gate puts out a one whenever all
inputs are logic one, so let's use an
for getting the end results quickly. AND. But the AND output is zero for
Before getting down to actual all other input combinations, and
techniques, it might be wise to do a
little reviewing. The truth tables for
DESIGN f(a,b,c) is a one for several other input
conditions.
the AND, OR, and NOT (or COMPLE- "Well, the AND gate did pretty well
MENT, or INVERTER) functions are A neat, simple method for the first input combination, so why
shown in Fig. 1. The function a AND b for working with logic. not try it for the second? Let's take
is written ab; a OR b is written a + b; the complement of b by passing it
and NOT a is written á. Note that + as through an INVERTER and run it into
defined here is different from ordi- BY ART DAVIS
an AND gate with a and c. This AND
nary addition, and merely symbolizes will put out a one when a =c =1 and
b =0, as desired. This seems to be
a b ab a b a+b a á
working well, so let's do the same
0 0 0 o o o o
to form more complex ones, it is ex- with each of the other two combina-
o I o o o pedient to have available two impor- tions."
I 0 o i o tant, yet simple, rules of basic logic With all the AND gates and INVER-
I I I I I I
theory known as DeMorgan's Laws. TERs arranged as above, our method-
NOT OR
AND COMPLEMENT Figure 3 contains truth tables for the ical experimenter will then observe
FUNCTION FUNCTION FUNCTION
logic functions ab, a + b, a + b, and that, since f(a,b,c) is to be a logic one
5. Comparing them yields the for- whenever the input variables form the
mulas of DeMorgan's Laws: first combination, or the second, or
AND GATE OR GATE INVERTER
1) ab =á +b the third, or the fourth, all he has to
Fig. 1
2) a + b = ab do is OR the outputs of the four ANDs
These formulas are useful in imple- to generate f(a,b,c). The resulting
menting digital functions using only logic is shown in Fig. 5.
the function defined by the truth table NAND or only NOR gates. Now this logic design works. It will
of Fig. 1. A truth table is simply an do the digital job, but it is inefficient.
array, one side of which contains all Why Map Techniques? A truth It requires four AND gates, one OR,
possible combinations of the input table is one way of specifying a logic and two INVERTERs. This is costly,
variables and the other side of which function -the Karnaugh map (pro- and it would cause quite a few layout
contains the corresponding values of nounced Kar -no) is another. To get an problems because of the numerous
a logic function -or output. Figure 1 idea of what such a map is, and why it interconnections. In addition, the de-
also shows the digital logic gate sym- is a convenient tool, let's look at a sign procedure outlined above is slow
bols for the three functions. practical digital design problem. and, for more complicated circuits,
Any logic function can be con- Suppose we are faced with design- error prone. What can be done to
structed from these three basic types ing the digital black box of Fig. 4, streamline the procedure?
of functions or gates. It is often con- which has three inputs a, b and c, and
venient, though, when working with a a single output f(a,b,c). The black box
a b ab a b á+b
particular type of logic family (TTL, o o o o
is to provide a logic one output under
DTL, etc.) to use two other types of the following input conditions: 0 o
function, the NAND and the NOR. The o I I o
NAND function of a and b is written a b ab a b a+b
o 0
ab, and the NOR function, a
I

Their 0 o I 0 o I

truth tables and logic symbols are il- 0 I I o I O

ábá+b
lustrated in Fig. 2. All of these func- Fig. 2 a b a+b a b ab
O o o
tions except the NOT, or INVERTER,
I I I

0 o I o o
can be extended in an obvious way to I I O I I 0
0 I 0 o o
include more than two inputs. With NAND
FUNCTION
NOR
FUNCTION
0 0 0
these functions at hand, it becomes I O

possible to construct any logic func-

tion desired.
In manipulating the basic functiöns
bob batb I I 0

a+b=ab
o

NAND GATE NOR GATE

Fig. 3
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ao- DIGITAL Fig. 4 implement our black box as shown in Definition: Two boxes are adjacent if
b0- BLACK f(a,b,c) Fig. 7. We have grouped together the the corresponding variables differ in
CO- BOX only one place, for example if one box
four adjacent squares to eliminate a
and b. Notice that we have simplified corresponds to a& and the other to
things a great deal, since we now abc. Notice that boxes on opposite
Fig. edges of the map are adjacent under
5 need no gates at all.
this definition.
Rule 1: If two boxes containing ones
Using a Karnaugh Map. Maps are adjacent, the single variable which
of one, two, three, and four vari- differs between the two (uncom-
ables are shown in Fig. 8. Maps of one plemented for one, complemented for
variable are rarely used, and maps the other) can be eliminated and the two
with more than four variables are sel- boxes combined. These two boxes cor-
dom needed -even if such a problem respond to the AND function of all the
were to chance along, the Karnaugh variables except the one eliminated.
map would not be the tool to use. Its Rule 2: If four boxes containing ones
value depends on the pattern recog- are adjacent in such a way that each
box is adjacent to at least two others,
The answer is the Karnaugh map. nition capability of the user, and it these boxes can be combined and the
This is just a rectangle divided up into becomes hard to recognize pattern two variables eliminated -those two
a number of squares, each square groupings in maps of more than four which appear in both complemented
corresponding to a given input com- variables. and uncomplemented form somewhere
bination. The Karnaugh map of our Using the three -variable map as an within the group. The group of four cor-
function f(a,b,c) is shown in Fig. 6. example, note that there is one box responds to the AND function of all the
The right half of the map corresponds for abc, one for abc, another for -abc-, variables except for the two which have
been eliminated.
to a =1, the left half to a =0 (â =1), the and so on, with abc corresponding to
Rule 3: The same procedure holds for
middle half to b =1, and so on. The the input combination a =1, b =1,
eight, sixteen, and so on, adjacent
basic idea is that there is one square c =1; abc to a =1, b =0, c =1; and ábc boxes. Each box in a grouping must be
for each input combination. If we to a =0, b =1, c =0; etc. Each box, adjacent to three, four, etc., others
write into that square the value of the then, corresponds to a single row in within that group.
output function for that particular the truth table. The map is arranged Rule 4: The various AND functions
input combination, we will have com- in such a way that half of it corres- produced by the above groupings are
pletely specified the function. The ponds to the uncomplemented form "ORed" together to yield the simplest
ones and zeros in Fig. 6 are the values of a given variable and the other half function.
which f(a,b,c) assumes for the as- to its complemented form; and the
sociated input variable combinations. variables are interleaved so that every It should be noted that a given box
Now recalling our methodical de- input combination corresponds to can be included in more than one
sign procedure, it is easy to see that exactly one square, and conversely. grouping if that will simplify the over-
each square which has a one in it cor- Usually only the uncomplemented all function, but each grouping
responds to the AND function of form of each variable is written -it should contain at least one box which
those input variables, and f(a,b,c) can being clear that the other half of the doesn't belong to an existing group-
be generated as the.OR function of all map corresponds to the com-
of the ANDs. plemented form.
A key factor arises here. It isn't Now, a logic function is displayed á a

necessary to include all of these AND by placing ones and zeros in the ONE- VARIABLE MAP

functions, and the Karnaugh map boxes on the map. If a given input
tells us how to eliminate some of the combination produces an output, or á a
terms. For example, looking at Fig. 6, function value, of one, a one is placed b
we see that f(a,b,c) is a one for four in the corresponding square on the TWO- VARIABLE MAP
b
adjacent boxes forming the bottom map. If the output is zero, a zero is

.
half of the map. (We will consider placed in the square. As an example,
squares on opposite edges to be ad- look at the logic function in Fig. 9. On
jacent.) It is also easy to see the fol-
lowing: The only variable which does
not change as we go from one square
the Karnaugh map, the box given by
abc has a 1 in it. This means that f is a
logical one when the input variables
M11 THREE -VARIABLE MAP

with a one to another with a one is c. have the value a =1, b =1, and c =1.
It remains at one. What this means is The box given by abc has a 0 in it.
that f(a,b,c) cannot depend on a and b This means that f =0 when a =1, b =1,
because, regardless of their values, and c =0. These entries, as well as all
f(a,b,c) is a one as long as c =1. There- the others, can be verified by looking
fore we can forget about a and b, and at the truth table.
d FOUR-VARIABLE MAP
The logic function in Fig. 9 is not at
c o 0 0 0
all simple looking. The question is,
how can the function be reduced to
c its simplest form? Variables can be b b

eliminated from the function by use of

Fig. 6 the following definition and rules: Fig. 8
SEPTEMBER 1975 51

www.americanradiohistory.com
 f=abc + abc +abc+ábc
LOGIC FUNCTION
defined by the truth table of Fig. 11. All the gate delays of delta
a b c f
This truth table introduces a new var- seconds -for illustrative purposes
0 0 0 0 o o o
iable, called a don't care and given only-are assumed to be lumped into
0 0 I o c o the symbol "X." The don't care means the output leads. The leads labeled x,,
0 I 0 0 b \bue b
that we can define the output func- x.. and x;, are the external inputs, and
KARNAUGH MAP FOR f tion fH to be either zero or one for that those tagged q,. q2. and q;, are the
0
particular input combination-simply
I I

outputs. (There could, of course, be

I

I o 0 I
because the input combination will any number of inputs and any number
I o I I never occur. A BCD counter never of outputs.) The leads labéled Q,. Q2.
I I 0 0 counts above decimal nine. The X's and Q. are assumed to respond in-
can be given values of zero or one so stantaneously to the inputs and fed -
as to simplify the resulting function. back outputs.
TRUTH TABLE FOR f In our case, the don't cares have been If the inputs have been in one state
Fig. 9 chosen as indicated by the smaller for a long time, the circuit will have
ones and zeros on the map. Notice settled into a stable situation with q,.
the very simple form for the function q2. and q;, identical with Q,. Q_, and Q:,.
f,_ which can be constructed from a respectively. Now suppose one or
f =a+bc single AND gate and an INVERTER. more of the inputs changes values.
Fig. 10 SIMPLIFIED FUNCTION The preceding was an example of Then no longer will the small q's be
what is called combinational logic. the same as the upper -case Q's. After
The outputs at a given time are de- the passage of (delta) time corres-
ing (otherwise, this would lead to re- pendent only upon the inputs at that ponding to the gate delays, though,
dundancy). time. Actually, the gates used to build the values of Q will have propagated
To illustrate, the Karnaugh map of up a logic function have some delay. through to the outputs, and the small
Fig. 9 is repeated in Fig. 10, along In the case of combinational logic, q's will again be identical with the
with the adjacency groupings and the though, this just means that after the large ones. For a given set of input
resulting simplified function. Note the input values are established, there is values, then, the small q's are called
contrast in simplicity. The boxes rep- some flat delay before the output the unstable states and the large ones
resented by abc and abc, although value is established. The delay is crit- the stable states of the sequential
adjacent, are not grouped together ical only if we have to compare the machine. The feature which allows
because each is already included in output value with another being simi- memory storage and other effects is
an existing grouping. Now we are larly generated. If this is the case, we the regenerative characteristics
equipped to tackle a real -life problem. could encounter problems with the created by the feedback.
timing margins.
BCD -to- Decimal Decoder. Con- In the digital game we are playing, The R -S Flip -Flop. An R -S flip -flop
sider the BCD counter of Fig. 11, though, the gate delays can be impor- is a one -bit digital memory whose
with the four output variables a, b, c, tant for a different reason. They allow output is set to the one state by a one
and d. Suppose we need to decode us to build so- called sequential on an input set (S) line and to the zero
the count of decimal eight and pro- machines for storing information, as state by a one on another line, called
vide a control pulse, lasting one clock well as for a myriad of other useful the reset (R). An incomplete truth
period, to some other digital circuit. things. The general idea of a sequen- table for this device is sketched in
We must build a logic function f, tial machine is illustrated in Fig. 12. Fig. 13. It is incomplete because the
output stable state is specified not
DECIMAL a b a d fe only in terms of ones, zeros, and don't
o o o o o o cares, but depends in addition on the
o o o o
present (unstable) state q. We can
form a complete truth table by includ-
2 o o o o
Fig. 11 ing q as one of the input variables,
3 o o o thus creating a feedback situation.
4 o o o o The complete truth table is also
b'
5 o o 0 KARNAUGH MAP FOR fe shown in Fig. 13, along with the re-
6 o o
fe =ad sulting Karnaugh map and the de-
o
SIMPLIFIED FUNCTION rived logic equation for the state Q.
7 o o Note that we must always have RS =O
8 o o o (called the RS flip -flop constraint) to
9 0

0
o

0
0

X
BCD
COUNTER XI-
x2
-%2!1
0 X X3
-DIGITAL GATES -
COMBINATIONAL LOGIC

(NO TIME DELAY)

221
0 o X

o X fe
o X

TRUTH TABLE FOR fe Fg. 12

52 POPULAR ELECTRONICS

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 R S Q R S q Q
above, to convince yourself that the Qn +I = S + RQn = JQn + (KQ)Q
0 0 q o 0 0 0 unit performs the R -S function. Now, applying DeMorgan's law to
TO, we_get
0 o o I I
The J -K Flip -Flop. Let's return to JQn + (K + Qn)Qn = JQn + KQn
o o o I 0 I
our newly developed map technique + QnQ,,
X o I I I now and develop the (clocked) J -K But q Q
= 0 always, so_
RS =0 0 0 0 flip -flop as a last example. For con- Qn -I = JQn + KQn
INCOMPLETE TRUTH TABLE
venience, since output changes are which is the J -K flip -flop equation.
0 0
allowed only on clock transitions, Notice that the R -S constraint is satis-
I

o X o I 0 X
let's denote the unstable state q by Q fied, since
q ,x 0 X and the stable state Q by Q +,. This is RS = (JQ)(KQ) = JK((Q) = 0
S' RS =0 reasonable, because Q. is the stable Fig. 16 shows the construction of the
KARNAUGH MAP COMPLETE TRUTH TABLE
state just prior to the nth 1 -0 clock J -K from the R -S using two AND
transition, and is the unstable state gates. Again, test the operation by as-
just afterward, with the flip -flop set- suming a set of conditions for J and K
tling down into the stable state Q and tracing the logic flow. A glance
Q = S + Rq
before the next clock transition oc- back at the incomplete truth table will
SO: 0=8+Rq curs. reveal that if J =K =1 (J and K inputs
= S + R +q The incomplete and complete truth tied to a logic one) the J -K forms a
(DE MORGAN'S LAW) tables are shown in Fig. 15, along toggle flip -flop.
with the Karnaugh map and the re-
Fig. 13 NOR-GATE -S FLIP FLOP
R
sulting simplified function. The J The preceding examples have been
serves as the S and K as the R, intended to accomplish two things. In
keep from violating the condition that respectively, of an R -S flip -flop. The the first place, knowledge of the logi-
R =S =1 must never occur. Figure 13 only difference is that the J =K =1 cal operation of the various types of
also shows how DeMorgan's Law is output is now defined (Q ). flip -flops is essential in order to use
used to get the function into a form Let's use the clocked R -S flip -flop them intelligently in an original de-
requiring only NOR gates for its con- to build the J -K from our derived sign. As a second objective, they have
struction. By assuming all three pos- equation. For this purpose, let S =JQ provided an effective demonstration
sible combinations of input variables and R =KQ be the inputs to the of the economy of thought which re-
(remembering the R =S =1 is disal- clocked R -S. According to the R-S sults when the Karnaugh may is used
lowed from ever occurring) and com- equation, in a digital design effort.
puting outputs, the truth table can
easily be verified. It is also easy to CLEAR
show in this way that the output
labeled Q is, indeed, the complement
of the output labeled Q for all input
conditions except the disallowed INPUT
MASTER
TRANSFER
GATES GATES
R =S =1.

The Clocked R -S Master -Slave

Flip -Flop. It is often desirable to
PRESET
have available an flip -flop which
R -S
changes state only on, for example, CLOCK
the trailing edge (or 1 -0 transition) of (CL)
CLOCKED MASTER SLAVE LOGIC DIAGRAM
a clock signal. It is possible to use the
Karnaugh map to derive the form of 0 ó
I I
such a flip -flop, but the end result, al-
PRESET 0 1--CLEAR
though economical in number of
I I

gates and number of inputs per gate, S CL R

would not shed much light on the in- I I I

Fig. 14
ternal workings. R -9 SYMBOL
K Qk+I K Ok Qk+I
This type of sequential machine is
J

o 0 Qk O 0 0 0 Q ó
depicted in Fig. 14. When the clock
goes high, the R and S inputs are o o O 0 1 I

passed through the input gates and o O 1 0 0

Fig. 15
stored in the master. When the clock O 0
Qk 1 1

goes low, the input gates are dis- S CL R

INCOMPLETE TRUTH TABLE 0 0
abled, and the information is coupled
1 1

0
through the transfer gates into the 1 1 1

slave flip -flop. The function of the 1 1 0 1

preset and clear inputs is evident. Try 1 1 1 0

assuming a set of input values for R COMPLETE TRUTH TABLE
and S, and trace the information flow, KARNAUGH MAP
letting the clock change as described Qn + I = JQn +KQn
SEPTEMBER 1975 53

www.americanradiohistory.com
 404y$
/,moi

BUILD A
DIRECT READING
LOGIC PROBE
Seven -segment readout displays high, low, open, and pulse.

BY R. M. STITT

THE LOGIC probe is almost a The letters are: H (high logic level), compatible. The outputs of the two
necessity in checking digital cir- L (low logic level), o (open), and P comparator circuits are further buf-
cuits. Usually the probe detects and (pulse). This type of display makes fered and conditioned by IC2, the high
discriminates between high -level, testing faster and improves accuracy (H) and low (L) outputs of which are
low -level, and pulse conditions at var- in reading the results. decoded by the remaining circuitry.
ious points in a digital circuit. The re- Assuming that the point under test is
sults are then displayed on miniature How It Works. Shown in Fig. 1 is the either at a constant high or a constant
lamps or discrete light- emitting logic probe's schematic diagram. low, the end result will be an H or an L
diodes. Transistor Q1 functions as a voltage displayed on DIS1.
If you want a more advanced logic comparator and buffer with a In the event of any pulse activity at
probe, try the one described here. It threshold of approximately 0.6 volt. the point under test, one -shot mul-
does what the conventional probe Transistor Q2 and diodes D1, D2, and tivibrator /C1 will trigger and generate
does, but has the additional capability D3 function as a voltage comparator a P(forpulse) on DIS1. If a single pulse
of being able to sense an open circuit and buffer with an approximate occurs at the test point, /C1 will still
or an out -of- tolerance high or low 2.4 -volt threshold. These thresholds cause a P to be displayed, but only for
logic level. And the indicator is a are slightly wider apart than is stan- about 0.5 second. (The probe is capa-
single seven -segment LED display. dard for TTL devices, thus providing a ble of capturing pulses as short as
The four possible test conditions are safety margin. 10 ns in duration.)
shown as actual letters on the seven - Resistors R4 and R5 and transistor Any time the probe tip is not touch-
segment display. Q3 shift the level of Q2 to make it TTL ing a point in the test circuit or is
54 POPULAR ELECTRONICS

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 are indicated in phantom in Fig. 2.)
4-SV C3
ors 1,14 After wiring the circuit board. solder
a "(25 mm) length of insulated wire to
1
DI
+5V
the pad under DIS1 nearest the end of
D2
the board. The free end of this wire
a
D3 goes to the probe's test tip. Prepare
the ends of two 36" (about -m) 1

DIS I
02 lengths of test -lead cable, and solder
one end to the 5 -volt and ground
RI
47K
pads on the board.
PROBE
R3
Now. cut a3%4 "long by5132 "deep (19
IOK
R2
3.8 -mm) window 1/2" (13 mm) from one
47K
end of the tube. Use CPVC tubing: it
has thinner walls to provide a slen-
01
R4 derer assembly than is possible with
10K
ordinary PVC tubing. CPVC tubing is
C2
220pF available from most hardware and
building supply stores.
You can fabricate the end caps for
RS
10K the tube to the dimensions given in
Fig. 3 by turning on a lathe or whit-
tling with a knife S/S" (16 -mm) diameter
COMMON
hardwood dowel stock. If you don't
have access to a wood -turning lathe or
don't relish whittling. you can fashion
PARTS LIST blunt end caps from 1/2" hardwood
dowel stock and use small screws to
hold them in place. In either case, drill
b -volt tantalum electroly- (2N3906 or similar)
tic capacitor The following are 1/4-watt, 5e4 tolerance a 14 (6.5 -mm) diameter hole through
( 2 -220 -pF ceramic disc capacitor resistors the rear end cap and a hole just large
D1 thru D4- Signal diode (IN914 or simi- R I ,R2-47.000 ohms
lar) R3.R4.R5.R14,RI5- 10.000 ohms enough to require force fitting a 6d
I)ISI-Common cathode seven- segment R6- 22.(XX) ohms finishing nail into it through the front
1.FD display (()pcoa SLA -7 or similar) R7 thru R -180 ohms
13 end cap.
IC I-Retriggerable monostable multivi- Slisc.- Printed circuit hoard: 71/4" x 1/2"
Pass the power leads for the probe
brator(74122_) inner diameter CPVC plastic tubing; st,"
I('2 -Hex inverter (7405) or 1/2" diameter hardwood dowel stock through the hole in the rear end cap.
1C3-Quad two -input NAND gate (7400) (see text); one red - and one black - Connect and solder a red -booted al-
QI.Q3 -Npn silicon switching transistor hooted alligator clips; 72" length of No.
(2N3904 or similar) IR test lead cable; 6d finishing nail: sol- ligator clip to the -5 -volt and a black -
Q2-Pnp silicon switching transistor der: etc. booted alligator clip to the ground
Fig. I. Schematic diagram of the logic probe. cables.
Tatasiatm.s Qi ourl Q1 up(' iii r+rrrrlxn7rloi'circuits which Test the probe by connecting its
set ihr logic levels. 1(7 oud l('.i decode the sigrurl. power cables to the 5 -volt and corn-
mon buses of a known good circuit
and touchirg the probe lead to the
5 -volt bus. common bus, and a point
touching a point that is electrically iso- To keep the electronic assembly as in the circuit where there are pulses.
lated from the circuit. DIS1 will display compact as possible. a printed circuit When the power leads are initially
an 0. Furthermore. any logic level that board is a must for component mount- hooked up, the display should indi-
is within the range set by the com- ing. The etching and drilling and com- cate 0. Touching the probe lead to the
parators will also result in an o being ponent placement guides are shown 5 -volt and common buses should
displayed. in Fig. 2. Since you will be making your cause an H and an L to be displayed.
In operation. H indicates a high TTL own double -sided board and will not respectively. With the probe lead
state (greater than 2.5 volts): L be able to plate through the holes, it is touching a point in the circuit where
indicates a low TTL state (less than 0.6 important to solder connections on pulse activity is taking place, the dis-
volt): o indicates an open circuit or an both sides of the board. Conse- play should indicate a P.
out -of- tolerance TTL state (high im- quently. you must install the compo- The circuit board is deliberately
pedance or less than 2.5 volts but nents in a set sequence. Install and wider than the inside diameter of the
greater than 0.6 volt): and P indicates a solder into place R7. R9, R13, and R15 plastic tube. To get the board into the
pulse train or single pulse. before you install R8. R10, R11. and tube. you will have to deform the latter.
R12. Likewise. install C2 before Cl. To do this, pace the tube between two
Construction. When assembling the All remaining components can be in- blocks of wood in a vise and very care-
probe. parts layout and lead dress are stalled in whatever sequence you de- fully close the vise just enough to
not particularly critical. The test prod sire. (Note: The component placement permit the board to slip into place. Be-
lead should be kept as short and direct guide shown in Fig. 2 is the view from fore opening the vise, make certain
as possible through the junction of R1 the top, or component, side of the that the display is centered in the win-
and R2. board. The items to be installed first dow of the tube.
SEPTEMBER 1975 55

www.americanradiohistory.com
 02

`
DIS ICI IC3 R'3 eC
1
!?,.,
C
RI
R4 QI
I

03
R14.

Lrè
i
* . 1+l! +
.

4
r8
l-e p
Fig. 2. Etching and drilling guides and
lo
u Oe
ié t -o i 4

4
1

88 8
*
¡ L---4 lri6

component layout for pc board are above. File or grind the point of the finish
ing nail to a sharp tip, contouring it
like a standard test -probe point. Drive
the nail into the front end of the cap,
leaving about 1/4" of the nail head free.
Fig. .1. Diagram shows how to assemble the Locate the free end of the probe tip
probe. Be sure display shows in the window. wire coming from the circuit board.
Strip away about 3/8" of insulation from
3/4" LONG 1/2 "INNER
X 3/32 "DEEP
DIAMETER FRONT the wire, wrap the exposed wire
5/8 "DIA MAKE PRESS CIRCUIT END
FIT FOR TUBE WINDOW I/2" POWER BOARD CAP TEST around the nail head, and drive the
CABLES TIP
nail home in the end cap. Push both
end caps into the tube (and secure
7 I /a" - them with small screws if necessary),
I/4" THICK and the probe is ready .to use.

(you don't have to buy a new car to get an electronic ignition.

Most of you know the evaluation of automotive electrical sys-
tems an evaluation characterized only occasionally by
. . .

efficiency and performance. know that, and that's why use

I I

the Delta Mark Ten B CDI on all my cars, new and old. And
believe me, you don't have to have a new car to appreciate
the best electronic ignition available today. Study these fea-
tures and you'll know what mean. I

1. Mark Ten and Mark Ten B Capacitive Discharge Ignition

Systems are manufactured by Delta Products, Inc., a company
with a conscience, and with a proven record of reliability both
in product and in customer relations.
2. The Mark Ten CDI's really do save money by eliminating
the need for 2 out of 3 tune -ups. Figure it out for yourself. The
first tune -up or two saved pays for the unit, the rest is money
in your pocket. No bunk!
3. Because the Mark Ten CDI's keep
your car in better tune, you actually
can save on expensive gasoline.
4. With a Mark Ten, spark plugs stay
clean and last longer fouling is ...
virtually eliminated.
No matter what kind of car you drive, it too can use a Delta
quality lift.
Iwant to know more about Mark Ten B CDI's. Send me complete
no- nonsense information on how they can improve the performance
of my car.
Name

Address
City State 7ip

DELTA PRODUCTS, INC.

P.O. Box 1147, Dept. PE, Grand Junction, Colo. 81501
303 -242 -9000

Mark Ten B, Standard Mark Ten,

assembled . . $64.95 ppd assembled .. $49.95 ppd
Mark Ten B, kit $49.95 ppd Deltakit® $34.95 ppd

CIRCLE N0. 18 ON FREE INFORMATION CARD

www.americanradiohistory.com
 down from the trailing edge to the next
leading edge, we can determine
whether the pulse is long or short. If,
as shown in the upper waveform of
Fig. 1. we can count down to zero be-
fore the next leading edge. we know
that the data bit was a "O If, however,
the counter is stopped by the leading
edge of the next pulse (lower
waveform). we know that the bit was
By Jerry Ogdin long and the data was a "1.
HOBBYIST INTERCHANGE TAPE SYSTEM Unfortunately. steep -edged pulses
are unacceptable to most cassette re-
corders. So we convert them into
audio tones, with a data pulse rep-
COMPUTER hobbyists have an in- zero bit represented by a short burst resented by a burst of approximately
satiable appetite for new pro- and each one bit by a long burst. Here 2000 Hz, which is compatible with
grams. Consequently, they are increas- is how it works. most low -cost recorders. The schema-
ingly using the practice of sharing tic for the complete HIT translator is
their programs. Basic Theory. Every digital pulse shown in Fig. 2. and the associated
But efficient sharing requires a has a leading and trailing edge: a bit waveforms are shown in Fig. 3.
common communications medium. interval extends from the leading edge The output of the computer consists
Short programs can be exchanged of one bit to the leading edge of the of two data lines from an output port
easily by correspondence on a type- next. If we synchronously count up latch. One (Fig. 3A) is called the en-
writer or even longhand. As software during the time from the leading edge velope and is true during the tone
becomes more complex. however, the to the trailing edge. as shown by the burst. The ether (B) is called modula-
possibility of translation error in- dotted line in Fig. 1, and then count tion and is a software -controlled
creases so it is essential that a univer- 2000 -Hz square wave. Op amp IC1A
sally recognized exchange medium be DATA
converts the TTL -level signals into an
used. Further. price and simplicity are approximate 2-kHz sine -wave burst
of great importance since many hob- (D) which can be recorded easily on
byists can't afford expensive corn - any tape machine. The output of IC1A
mercial equipment.
With no such common exchange
medium available to hobbyists today.
we have taken the bull by the horns
DATA
I BIT INTERVAL - -
is about 2 volts peak -to -peak at the
Aux output jack and about 50 mV at the
mic jack. When recording on a stereo
cassette, write this data into the right
and developed a standard which we 1. Pulse iraretaruis show hoir channel.
think meets all of the foregoing re- zero owl one hits differ in letlgll . The playback circuit takes the re-
quirements. We call it the Hobbyists
Interchange Tape System or simply
HIT. The system uses an ordinary
low -cost audio cassette tape recorder
as the hardware /software interface:
and it can be adapted for use with any
computer. In the following discussion. To
TAPE
HIT is used with an 8080 CPU -design REC

microcomputer.
HIT is probably not the most effi-
cient nor simplest possible system.
but we think it is the best compromise DI, 02 -ANY SILICON DIODE
ICI -QUAD OP AMP, MC3401P OR LM3900N
for public interchange of software. At
the tape speeds used. data will appear R9
220K
on the tape at rates between 30 and
360 bits per second -not a blindingly
fast speed, but reliable! However, by FROM TAPE
R7
22K ICIB
O
13

changing some of the circuit and

software values and using a high -
REC
(AUDIO
IN)
C3
.005pF 1 RIO
220K
RECT
J6
TO
COMPUTER

quality recorder, 2500 bits per second R14

can be achieved. I

_
F
D2
IK

The technique does not depend on R8 ICIC CS

22MAAAAA 10 47pF
frequency, amplitude. or phase. In- 1?
C4
deed, the low -cost cassette recorder SQUARING AMP .001yF SCHMITT
TRIG
does not even have to handle digital
pulses directly. In practice. short and h'ig. %. :1l lop is schematic for recording end 4111T
long bursts of tone are used, with each system. ('irrait at bottom reads t/'(lm cassette into rampaler.
SEPTEMBER 1975 57

www.americanradiohistory.com
corded data signal from the tape re- durations and still be able to recover
corder (Fig. 3E) and converts it back to them successfully.
the original digital signal. This circuit,
consisting of IC1B, C, and D, works Programs. The software we have
with an input signal level from 0.75 V used with an 8080 is shown in Pro-
to 4 V, although 2 to 2.5 V is ideal. The gram 1 (overleaf). The output port 2.5V -
input is squared up in IC1B and IC1C (named TAPEO in the program) puts C 1.6v
(Figs. 3F and G) and then rectified by the envelope signal on the most - iv-
0-
diodes D1 and D2. The combined out- significant bit and the modulation on .8V-
put (H) is then applied to a Schmitt the least- significant bit. Since most D 0-
trigger (IC1D) which produces the output ports are TTL- compatible, the
output signal (I), an exact reproduc- simple writing circuit of Fig. 2 can be
tion of the original envelope input. directly connected. Each data bit is E

The frequency of the tone burst is shifted into the CARRY flag of the com-
5V-
not critical. In writing a tape to be puter, where the decision to emit a F
mailed to another person, use a fre- short or long pulse is made. The .6V-
OV-
quency near 2 kHz as the modulating least- significant bit of the counter is 5V-
input. The reliability of the recorded used to determine how long to emit G
o-
data depends on how long each pulse the tone burst (modulation) signal.
is written. With very brief tone bursts,
the data rate is high, but the reliability
can be adversely affected by poor -
After all of the tone burst has been
sent out, we wait in a counting loop
(built into the program) for some tape
H
5V-

.6VV
rflrtiin
quality tape and inexpensive cassette to move past the recording head be-
recorders. Each bit may be as short as fore starting the next output bit. I
1250 microseconds or as long as 35 Nine bits are written for each 8 -bit
milliseconds, depending on the writer byte. Since this new recording Fig: 3. Waveforms at various
of the tape. In the programs that fol- scheme uses the leading edge of a points in the writing and
low, 2.75 milliseconds is used as the burst as the "clock," it is necessary to reading circuits of the HIT.
bit time. The playback circuit and assure that there is a data bit after the
software should be capable of adapt- eighth bit of a byte. This ninth bit is timed. Consequently, do not change
ing automatically to pulse lengths always written as a "0 ". The time that the instruction sequences unless you
since it is the ratio of the first half to it takes this bit to move past the re- fully understand the timing relation-
the second half that determines the cording head is the time that we can ships of the instructions.
data value. use to process the character and store In reading the data back in, the input
With this wide range of permissible it away in memory. port (the least significant bit is used) is
pulse lengths, virtually any computer The data rate is 364 bits per second, examined until a zero -to -one transi-
can be used to write these standard using all the values in the illustrations. tion is found; that is the leading edge
format tapes. Even the slower 8008 This writing routine, like the reading of the burst. We now count up (in the B
CPU can write out bits that have -ms 1 routine of Program 2, is critically register) until the trailing edge is

DATA TO
A B C D E F G H I K L M N o P 0 R S T U V W x Y z RECORD

SS SS
YYYY
NN NN
5 G H I K
E

X
0 0
}STANDARD
BLOCK Fig. 4. How data to
be recorded is first
00 0 0 translated to ASCII
00 O 0
00 O 1 code and then put
II O I
ASCII on tape as tone bursts.
00 O 0 DATA
1 1 I

II 0 I

,00 I I

L.S.B. FIRST
0 1 1 0 1 0 0 1 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0
I

I SERIAL DATA

ENVELOPE
' 0: 0' I I' 0' 0' I'

TAPE

.._ MOTION

58 POPULAR ELECTRONICS

www.americanradiohistory.com
found. After that, we count down until
either a new leading edge is detected
tion the writer wishes to employ here.
If the block -check characters are
The
(making the data bit a 1), or the used, the writer of the original tape is
counter goes to zero (data is a 0). Note expected to provide a computer pro-
that each bit condition must be sensed gram in the first few data blocks for the
two times in succession to be consid- machine of interest that will read and
ered valid. This provides noise pro- utilize them. This program should ap-
tection. pear at the front of the tape and be
Each time a bit is found, it is shifted terminated by an end -of -file block.
into place. After eight bits are located, The data to be read in should then
the return is taken. When the charac- follow on the tape. This front -end
ter reading routine returns, the lead- program is called a "bootstrap
ing edge of the ninth bit has thus al- leader."
ways been sensed. Programs for reading and writing
standard format data tapes from
Data Format. Having a standard memory of an 8080 are shown in Pro-
medium and a standard recording gram 3. We can read or write 1024 bits
form is not enough for successful in about 30 seconds using the stan-
computer data exchange. We must all dard format.
agree on the code and format of the
Introducing the family of modular micros
data. As far as possible, the method Higher Speed. This cassette inter- from Martin Research!
described here uses national and in- face can also be used locally for nor- Choose either the economical 8008 proces-
ternational data communications mal input/output needs. However, in sor, or the powerful 8080. Either CPU is
standards. All data is written in ASCII your own computer, you may be able compatible with our advanced bus structure!
Plus, a convenient monitor program, in
code unless otherwise agreed upon by to go substantially faster. Our experi- PROM memory, allows you to enter instruc-
writer and reader. It is possible, for ments have shown that you can expect tions with the ease of ai handheld calcul-
example, to agree on the transmission to have a data bit rate about one - ator. Six I!arge digits display data in octal
format.
of actual eight -bit object code. All data fourth of the modulation frequency. If Modularity ma <es for ease expansion. First
is recorded with the least- significant your tape recorder will faithfully re- quality parts throughout. Professionally
bit first. produce a 10 -kHz signal, as many bet- made PC boards with platted holes, solder
mask protection. 8080 CPU board features
The record format we use is shown ter decks do, you can expect to handle versatile interrupt structure, multiprocessing
in Fig. 4. This technique is synchron- 2500 bits (240 characters) per second. capability. Easy interfacing to input and
ous, and from the beginning of the You may also want to add some ad- output ports.
data to the end, there should be no ditional hardware to eliminate some of MIKE 3034: CPU boardl with 8080, key
board / display board, PP OM, board
dead spots. At this time, it should be the software. A simple gated oscillator monitor PROM (256 bytes of RAM),
pointed out that cassette recorders can be used instead of performing the breadboarc, hardware, and instructions:
have agc or limiter circuits. When the modulation in software. The envelope $395.00 kit, $495.00 assembled and tested.
data first appears at the record input signal can drive the gate of an oscil- MIKE 203A: CPU board with 8009, key -

board /display, PROM /RAM, breadboard,

of such a machine, the agc does cruel lator. You can even go so far as to have hardware, and instructions: $270.00 kit,
things to the waveshape. By not allow- an eight -bit parallel output bit port and $345.00 A&T.
ing this to happen, except in the first perform all of the timing and serializa- MIKE 3 -5 or 2-5: 4K RAM board with
450 ns static RAM. $165.00 kit, $190.00
part of the data where it is permissa- tion external to the computer. You will A &T.
ble, many problems can be avoided. probably want to have two versions of F R E E C A T A L O G!
This is done as follows: Each data these circuits: one to be used to write Kits: US & Canada only.
block begins with at least 32 ASCII standard tapes at standard frequen- Master Charge accepted.
SYN (synchronizing codes 0001 0110). cies and rates, and the other to write at OEMs: write for
quantity prices.
The SYN codes repeat long enough to whatever speed your own tape record-
allow the recorder's agc to settle down er can handle without errors.
and the software to go into character The playback circuitry can also be
"sync." A special character signal at expanded. The count -up /count -down
the start of text (ASCII STX code 0000 software can be converted into a cou-
0010) appears next, followed by an ple of timers that control ramps. Simi-
eight -bit count word. That count larly, you may want to assemble in-
specifies how many more characters coming bits into eight -bit characters
appear in the date record. If the count in hardware. With all this hardware in-
is zero, then this is called an end -of- stalled (it takes about 10 IC's), the
file block. If it is not zero, it specifies software becomes only a few input
how many eight -bit bytes appear in the and output statements.
data record. At the end of the data What is needed now is a central ex-
bytes (if any), is an ASCII ETX (end -of- change point. Perhaps some of the
text 0000 0011) character and two emerging hobbyist groups (or even
block -check characters. These two individuals) will agree to create a li- MARTIN RESEARCH
Microcomputer Design
characters are normally zero, but can brary of tapes for exchange or have 1825 S. Halsted St.
be used to hold the CRC code, or a them available at a nominal charge. A Chicago, IL 60608
(312) 829 -6932
check -sum, or whatever error protec- brief listing of program function,
CIRCLE NO 34 ON FREE INFORMATION CARO
SEPTEMBER 1975 59

www.americanradiohistory.com
PROGRAM 1 NOP
MVI A,RDTIM+2
;WRITE THE BYTE IN THE -C- REGISTER OUT TO TAPE, CALL RDBIT ;CONFIRM
LEAST- SIGNIFICANT BIT FIRST. AFTER EIGHTH BIT MVI A,2
WRITE OUT A DATA '0'. REGISTERS (A 6 B) ARE JC RDCH3 ;EARLIER '0' WAS NOISE
DESTROYED. OCCUPIES 74 BYTES. MVI A, -2 ;BEGIN TO COUNT DOWN
COUNT DOWN AFTER TRAILING EDGE
VARIABLES -WRWAI- AND -WRLEN- CONTROL DATA RATE. RDCH5: ADD B ;DECREMENT RAMP COUNT
-WRWAI- DEFINES PERIOD OF EACH MODULATION HALF- MOV B,A
; CYCLE; -WRLEN- DEFINES LENGTH OF EACH DATA BIT. JNC RDCHO ;DATA BURST WAS SHORT. DATA ='0'
DATA RATE IN BPS IS: MVI A,RDTIM+1
1000000 CALL RDBIT ;READ NEXT SAMPLE
BPS = MVI A, -1
(15 WRWAI + 64) (6 WRLEN - 1) C JNC RDCH5 ;STILL '0', CONTINUE COUNT DOWN
WHERE -C- IS 8080 CYCLE TIME IN MICROSECONDS CONFIRM CLOCK (NEXT LEADING EDGE)
WRWAI EQU 29 ;2004 HZ IF C =500 NANOSECONDS NOP
WRLEN EQU 2 ;REDUNDANCY = 2 MVI A,RDTIM+2
GET NEXT DATA BIT TO TRANSMIT CALL RDBIT :GET SAMPLE TO CONFIRM
WRCHA: MOV A,C MVI A, -2
STC ;JAM IN STOPPER BIT JNC RDCH5 ;EARLIER '1' WAS NOISE
WRCHX: RAR ;GET LEAST- SIGNIFICANT BIT FOUND NEW LEADING EDGE; DATUM = '1'
MOV C,A ;SAVE ALL OTHER BITS FOR LATER MOV A,C
LDA WRLNG (FOR DATA '1')
; RAR ;INSERT '1' INTO BYTE
JC WRBST MOV C,A
LDA WRSHT (FOR DATA '0')
; RC ;IF STOPPER BIT IN -CY -, QUIT
WRITE TONE BURST OUT TO TAPE MVI B,2
WRBST: CALL WRTIM ;WRITE OUT FIRST HALF -CYCLE MVI A,RDTIM
JZ WRFIN (GO DO LONG PART NOW) JMP RDCHR ;GO CATCH THIRD SAMPLE
CALL WRTIM ;WRITE OUT SECOND HALF -CYCLE COUNTED DOWN TO ZERO; DATUM = '0'
JNZ WRBST (KEEP GOING) RDCHO: MOV A,C ;INSERT '0' INTO BYTE
OUT TAPED ;TERMINATE MODULATION RAR
LDA WRSHT (GO DO SHORT PART NOW) MOV C,A
JMP WRDLY -1 JNC RDCHC ;GO WAIT FOR LEADING EDGE
WRFIN: OUT TAPEO ;TERMINATE MODULATION IN TAPEI ;AT END OF BYTE, BE SURE
LDA WRLNG RRC ; TO AWAIT LEADING EDGE
WRITE OUT NO MODULATION FOR REST OF BIT TIME JNC $ -3 ; OF TERMINAL '0' BIT
MOV B,A RET
WRDLY: CALL WRTIM+3 ;JUST DELAY TIMING DELAY FOR READ SAMPLE PERIOD
JMP $ +3 (WASTE MORE TIME)
; RDBIT: DCR A ;DELAY
MOV A,A JNZ RDBIT
JNZ WRDLY IN TAPEI
PREPARE NEXT BIT FOR OUTPUT RRC ;PUT SAMPLE INTO CARRY BIT
MOV A,C RET
ORA A ERROR ROUTINE. CLEAR CARRY TO REPORT ERROR
RZ ;IF ZERO, CHARACTER'S ALL DONE RDCHE: XRA A
CPI. 1 ;IF 1, WE'VE FOUND STOPPER BIT RET
JNZ WRCHX ;(JUST ANOTHER DATA BIT)
XRA A ;EMIT A TERMINAL '0' ROGRAM 3
JMP WRCHX ;READ A BLOCK OF DATA FROM TAPE INTO LOCATIONS
TIMING DELAY LOOP FOR CONTROLLING MODULATION NAMED IN (H,L). REGISTER -E- WILL BE SET
WRTIM: MOV A,B ;GET COUNTER WORD TO THE INPUT BLOCK SIZE; (A,B,C,D) ARE ALL
OUT TAPED ;WRITE OUT CARRIER USED. OCCUPIES 60 BYTES.
MVI A,WRWAI ;SET UP WAIT UPON RETURN, FLAGS REPORT CONDITIONS FOUND:
DCR A ZERO CARRY CONDITION
JNZ $ -1
INR B ;UPDATE COUNTER 1 1 NORMAL DATA BLOCK
RET 1 0 END -OF -FILE BLOCK
;SHORT- AND LONG -BURST CONSTANTS 0 1 BAD BLOCK FORMAT READ
WRSHT: DB 255 -WRLEN -WRLEN +2 ;(MUST BE ODD) XXSTX EQU 2 ;ASCII START -OF -TEXT (STX)
WRLNG: DB 255- WRLEN -WRLEN -WRLEN -WRLEN +1 ;(EVEN) XXETX EQU 3 ;ASCII END -OF -TEXT (ETX)
XXSYN EQU 20 ;ASCII SYNC CODE (SYN)
PROGRAM 2 RDBLK:
SET WORD -SIZE STOPPER BIT IN -C-
MVI C,128
;READ A BYTE FROM TAPE INTO THE -C- REGISTER. CALL RDCHC ;AT OUTSET, READ ANYTHING
-C- IS LOADED LEAST -SIGNIFICANT BIT FIRST MOV A,C
INTO THE MOST -SIGNIFICANT POSITION. 122 BYTES CPI XXSYN ;SEE IF SYN FOUND YET
JZ RDSYN
SAMPLE PERIOD FOR INCOMING DATA IS SET BY -RDTIM -, GET ONE MORE BIT TO SEE IF SYNC CODE YET
WHICH IS COMPUTED AS: RDNXT: ORI 1 ;SET TO READ ONLY ONE BIT
T - 100C (T IS TIME IN USEC, MOV C,A
RDTIM - C IS 8080 CYCLE TIME JMP RDBLK+2
15C IN USEC) CONFIRM THE SYNC CODE FOUND
RDTIM EQU 7 ; TO SAMPLE EACH 100 USEC RDSYN: CALL RDCHA ;READ A SECOND SYNC CODE
SET UP NORMAL WORD -SIZE STOPPER MOV A,C
RDCHA: MVI C,128 CPI XXSYN
IN TAPEI ;AWAIT DATA '0' CONDITION JNZ RDNXT
RRC BEFORE LOOKING FOR FIND THE STX AND COUNT WORDS
JC RDCHA+2; LEADING EDGE CALL RDCHA
MVI A,RDTIM+2 MOV A,C
CALL RDBIT ;WAIT FOR SAMPLE PERIOD, CPI XXSTX
JC RDCHA +2
; THEN CONFIRM '0' JNZ RDNXT ;LOST SYNC. TRY AGAIN
FIND AND CONFIRM LEADING EDGE OF DATA BURST CALL RDCHA ;READ IN BLOCK SIZE
RDCHC: IN TAPEI ;LOOK FOR LEADING EDGE MOV A,C
RRC MOV D,C ;SAVE FOR OUR COUNTING
JNC RDCHC MOV E,C ;SAVE FOR THE CALLER
MVI B,1 ;INITIALIZE RAMP COUNT ORA A
MVI A,RDTIM+2 RZ ;IF ZERO, RETURN END -FILE.
CALL RDBIT ;GO CONFIRM LEADING EDGE READ IN DATA BYTES AND STORE THEM AWAY
JNC RDCHC RDATA: CALL RDCHA ;READ NEXT DATA BYTE
MVI A,1 ;CONFIRMED. START COUNTING MOV M,C AND PUT INTO STORAGE
RAMP UP ( -B- REGISTER) UNTIL TRAILING EDGE INX H ;ADDRESS NEXT BYTE
RDCH3: ADD B ;INCREMENT RAMP COUNT DCR D ;SEE IF WE'RE DONE YET
MOV B,A ;SAVE RAMP COUNT JNZ RDATA (NO)
JC RDCHE (BAD DATA; PULSE TOO LONG) READ AND PROCESS BLOCK EPILOG
MVI A,RDTIM+1 CALL RDCHA ;READ IN ETX CODE
RDCHR: CALL RDBIT ;GO READ NEXT SAMPLE MOV A,C
MVI A,1 SUI XXETX ;SET ERROR FLAG
JC RDCH3 ;IF SAMPLE _ '1', CONTINUE COUNT STC ;MARK NOT -EOF
CONFIRM TRAILING EDGE RET
60 POPULAR ELECTRONICS
www.americanradiohistory.com
PROGRAM 3 (Continued)
;WRITE A BLOCK OF DATA TO TAPE FROM THE ARRAY CALL WRCHA ;WRITE OUT THE STX CODE
STARTING AT ADDRESS IN (H,L). DATA IS MOV C,E
ASSUMED TO BE IN ASCII AND THE NUMBER OF CALL WRCHA ;WRITE OUT COUNT
CHARACTER TO WRITE IS IN -E -. IF -E- = 0, DETERMINE WHETHER DATA NEEDS TO BE WRITTEN
WRITE A NULL BLOCK AS END -OF -FILE. MOV A,E
(A,B,C,D,E) ARE USED. (H,L) WILL END UP ORA A ;IF COUNT =O,
POINTING TO END OF ARRAY + 1. USES 50 BYTES. JZ WRBLF DON'T WRITE ANY DATA
WRITE OUT DATA BLOCK
RECORD FORMAT: WRBLL: MOV C,M ;GET DATA BYTE
SS SSSN EBB INX H
YY...32...YYTN...DATA...TCC CALL WRCHA ;WRITE BYTE OUT
NN NNXN XCC DCR E
XXBCC EQU 0 ;DUMMY BLOCK -CHECK WORD JNZ WRBLL ;REPEAT UNTIL DONE
WRITE OUT SYNC CODES AT FRONT OF BLOCK WRITE OUT BLOCK EPILOG
WRBLK: MVI D,32 WRBLF: MVI C,XXETX
MVI C,XXSYN CALL WRCHA ;WRITE OUT END -TEXT CODE
CALL WRCHA ;WRITE OUT NEXT SYN CODE MVI C,XXBCC
DCR D CALL WRCHA ;WRITE OUT BLOCK CHECK BYTES
JNZ WRBLK+2 MVI C,XXBCC
WRITE OUT STX AND THEN COUNT WORD (NNN) CALL WRCHA
MVI C,XXSTX RET

20 hi -fi watts
machine, and source could be highly
useful. For starters, reader David
Yulke, 121 Liberty Ave., Selden, NY
11784, wants to trade software at no

in 1.2 cubic inches

cost and offers PROM programming
and assembling service at nominal
cost to cover his time and postage. He
has a home -designed 8008 sytem with
cassette, CRT terminal, ASR -33 Tele- What a powerhouse! SK3154 packs passive components, power supply
type, and 1702A or 5203 programmer. a 20 -wattRMS audio amplifier in one and hardware -and you've got one
Software includes MON -8 modified for small module. With virtually flat channel of a fine stereo or quad ampli-
response from 15 Hz to 70 kHz. In the fier. The fun -and a super finished
UART operation and a RAM test fea-
SK3154 package you'll find all the product -are yours. (Ten and 15 -watt
ture; modified cassette routine, octal information you need. Just follow the SK modules also available.) Start now!
loader and hex loader (paper tape), all instructions for adding 12 easy -to -get See your RCA electronics distributor.
on 3 PROM's with an error routine. He
is working on a "black- jack" program
and a home accounting program. So
let us hear from any other readers who
wish to list such information.

Response. Thanks for the over-

whelming response to our first col-
umn in June. We're gathering material
on hobbyist computer clubs and will
alert writers as soon as our input is
complete. (POPULAR ELECTRONICS will
be increasing the frequency of this
column shortly as a result of so many
reader requests to do so. -Ed.)

Solid fun in 399 pages

Electronic organ, temperature alarm,
tachometer, light- operated switch -68
useful solid -state projects in one book.
Complete instructions plus some theory.
RCA
$2.95 optional price. At your RCA elec-
tronics distributor.
ll, ,,,rrrt.ti to ralt i/r n tErr other
RCA Solid State, Box 3200,
Somerville, N.J. 08876.
EmrxilltclNnri.., CIRCLE NO. 45 ON FREE INFORMATION CARD

SEPTEMBER 1975 61

www.americanradiohistory.com
 CONSTRUCTION

Consciously
SKIN TEMPERATURE controlling the blood
flow by measuring

THE RMOMETE R skin temperature is said to

improve several body functions.

BY COLIN SHAKESPEARE
DURING the past few years, a
lot of research has been direct-
ed at learning how to consciously con-
trol some of the "involuntary" body
functions. Electronics has played a
major role in this research, providing
the means for both sensing and
monitoring body functions. Among
the more commonly measured and,
hence, controlled body functions are
skin resistance, potential, and tem-
perature, as well as alpha, beta, theta,
and delta brain waves.
Our interest, in this article, is in skin
temperature, which is an indication of
the flow of blood in the peripheral
parts of the body (hands and feet). We
want a skin temperature thermometer PARTS LIST R6--3900 Ohms
that will serve to teach the user how to R7- 27,000 ohms
increase and decrease the flow of B -9-volt transistor battery R8-2700 ohms
I-
I

blood to his limbs. With training, it is

C 0.047 -µF capacitor R3- 10,000 -ohm linear -taper potentiome-
ICI- Comparator integrated circuit (311) ter
even possible to control the flow of J1-Two-contact jack S1 -Spstswitch (part of R3)
blood in each hand independently. MI-0- 100 -pA meter movement S2 -Dpdt switch
Controlling the flow of blood is one PI-Two-contact plug TDRI-Thermistor (Fenwal No. JA33J1)
way of solving the problem of cold
The following are 1/13-watt, IOr tolerance Misc. -Perforated board and solder clips;
resistors: socket for ICI; contact clip for Bl; suit-
hands and feet. Another use for this R1-3300 ohms able box to house circuit; machine
technique is the control of migraine R2- 22,000 ohms hardware; zip cord; hookup wire; sol-
headaches. Working on the theory R4,R5- 15,000 ohms der; etc.
that the throbbing headache pain is Difference between drop across TDR1 and reference is shown on Ml.
caused by the blood vessels in the
62 POPULAR ELECTRONICS

www.americanradiohistory.com
head being stretched (vasodilated) by condition and will not harm the meter
the flow of blood, when more blood is
diverted to the limbs, there is less to go
movement.)

Construction. The
Stravinsky
made us
to the head and the rest of the body. skin temperature
This reduces the pressure of the blood thermometer project can be made
in the vessels of the head, which, in very compact, as shown in the lead
turn, diminishes the pressure pain. photo. With the exception of B1, M1,
Once a person learns how to in-
crease the flow of blood in one limb
while reducing it in others, it is possi-
R3 /S1, S2, and TDR1, all parts can be
mounted on a piece of perforated
board that has holes on 0.1 " (2.54 -mm)
do it.
ble that he can control bleeding from a centers. Use a socket for /C1 and, if
wound. However, a great deal of phys- you want, solder clips for the rest of

exercised -
ical and mental self control must be

in the heat of the moment -

which may be impossible
for suc-
the components.
The meter movement, switched
potentiometer, range switch, and
cess. The uses to which such control input jack for the thermistor mount on
can be put are almost limitless. If a the front panel of a suitable enclosure.
person persists with regular training At one end of a 3' (about 1 m) long
over a period of weeks, considerable piece of thin zip cord, solder plug Pl.
control can be achieved. At the other end of this cable goes the
thermistor. Put insulating tubing over
About the Circuit. As shown in the the leads of the thermistor, and heat
schematic, the skin temperature sink TDR1 during the soldering opera-
thermometer's circuit is a simple con- tion. Slide the sleeving right up to the
figuration. Temperature sensor TDR1 thermistor's disc. As a final touch, Stravinsky ... and every
is an ordinary thermistor, while mi- apply a thin coat of lacquer or other composer who has ever written
croammeter movement M1 is the insulating material over the probe. music with the range, power and
Keep the coating as thin as possible to majesty of "Rites of Spring" ...
monitor indicator. Voltage variations, music that demands far more
resulting from variations in tempera- avoid increasing the time constant of
than any stereo can deliver
ture, from TDR1 are fed to the invert- the sensor. without adequate amplifier power.
ing input of comparator integrated When making hookups to the circuit The Phase Linear 700B Power
circuit/Cl. Inside the IC, this voltage is board assembly, keep the leads to the Amplifier faithfully reproduces the
compared with a reference voltage two inputs of the IC as short as possi- most difficult passages of the
applied to the IC's noninverting input. ble. If oscillation problems are en- most demanding recorded music.
The output from ¡Cl then provides an countered during checkout, which It lets all of the music through at

amplified voltage that drives M1. would appear as a high reading on the realistic volume levels. You never
For training purposes, two meter meter, reroute the IC's input wires have to reach for your volume or
away from the other leads and com- tone controls to prevent clipping.
ranges (scales) are useful. One must
The 700B has the highest
be fairly sensitive; so, for this, a zero - ponents in the circuit.
power, widest frequency
center scale with a range of ±2° C was response and lowest distortion of
chosen. An absolute scale, covering Checkout and Use. As potentiome- any stereo amplifier in the world.
the range from room temperature to ter R3 is adjusted through its range Take Stravinsky to your dealer
blood temperature is also required. with S2 in the RELATIVE position, a bal- and listen to what we mean.
This is important because once a ance point will be found. The voltage
subject's hands are within a few de- appearing across TDR1 during this
grees of blood temperature, no test should fall between 3.0 and 4.7
amount of control will get them any volts.
warmer. (Most users will find that Due to the tolerance of the thermis-
there is an upper temperature limit tor used in the thermometer, the ac-
that will vary from person to person by tual scale reading for blood tempera-
a degree or so. From atraining point of ture must be obtained by experiment.
view, then, you must pick a time when The absolute value of the temperature
the subject's hands are cool or start is not particularly important. What is
with training to reduce blood flow.) of importance is to learn by trial and
With S2 in the position shown, M1 is
on the ABSOLUTE scale, indicating
nominally from 200 to 40° C. In this
error the maximum temperature that
you can normally achieve.
To use the skin temperature ther-
,A,f6e
position, potentiometer R3 has no ef- mometer, the thermistor should be
fect, and at room temperature, the lightly taped to a finger. Then sit in a
pointer of M1 would be near the zero relaxed, comfortable position. The
index on the scale. Setting S2 to its
alternate position puts the meter on
more relaxed you become, the better
results you will achieve. Any tension
700-d3
THE POWERFUL DIFFERENCE
the SENSITIVE scale ( ±2° C), in which will completely override attempts to
increase the flow of blood in the PHASE LINEAR CORPORATION,
case, the pointer of M1 will peg at the P. O. BOX 1335,
left end of its travel. (This is a normal hands. LYNNWOOD, WASHINGTON 98036
CIRCLE NO 42 ON FREE INFORMATION CARO
SEPTEMBER 1975 63

www.americanradiohistory.com
 .._

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L-, 4,0 FEDERAL COMMENICATIO S COMMLSSIO/ '

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> JFAIDDIELIE151.41ILLNIA (0,111CISAFIVAIGIC,441SpiR
FIRST CLASS

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NOT VALID UNTIL SIGNED

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N.1 www.americanradiohistory.com
 CIE's Warranty says a lot to you!
A lotabout CIE's FCC License training Government certification of certain electronics knowledge
programs...and a lot more about our school. and skills.

Our FCC License Warranty means just what it says. If What about other CIE courses?
you enroll in any CIE career course that includes FCC In every CIE career course, you'll find the same time -
License preparation and successfully complete your train- tested instructional techniques that have made CIE's FCC
ing ... you'll pass the Government FCC exam. We warrant License preparation programs so successful.
that you'll succeed. Each CIE career course is built on the principle that
CIE can make this no- nonsense warranty because we're the best way for you to learn and retain what you've learned
confident of our in -depth career training programs. You is to explain; then to check your understanding; then to
see, we have specialized exclusively in Electronics educa- reinforce your comprehension with practical applications.
tion -by -mail for more than 40 years. Just Electronics. In some courses, you will perform experiments and tests
And, the courses we offer today are the result of these with your CIE Experimental Electronics Laboratory using
years of teaching experience and proven methods of authentic electronic components and gear. And, if you
training. select a course that includes Color TV technology, you
Our courses of study are written in easy -to- understand will not only build and keep a 25" diagonal Color TV
language, so you can progress at your own learning pace,
at home, in your spare time. And, there are never any
which features digital circuitry ...
you'll also learn how
to troubleshoot your TV.
classrooms to attend. The CIE course you select (beginner, intermediate, or
CIE courses challenge your thinking help you de- ... advanced college -level), will be a complete educational
velop your understanding of important electronics theories program, designed by experts to give you the best in Elec-
and applications ...
enable you to learn new skills and tronics home -study education.
knowledge. Our courses are thorough. They have to be.
You see, we're training you for a career in Electronics. Send for FREE school catalog
And, if an FCC "ticket" is part of your goal, you'll have
to pass a tough licensing exam administered by the Federal Discover more about the career opportunities open to
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Government). And you'll be prepared. courses can help you build new skills and knowledge and
CIE is willing to warrant that you will pass! The reason prepare you for a meaningful, rewarding career. Whether
is ... we have every reason to expect that you will do you are just starting out in Electronics or are a college -
trained engineer in need of updating, (or anywhere in
exactly that. Based on a series of continuing surveys, close
to 9 out of 10 CIE grads pass their FCC exams! between), CIE has a course designed for you. And, more
than half of CIE's career courses include FCC License
What's a license worth? preparation.
Send today for our FREE school catalog and booklet
An FCC License can be worth a lot if you're interested on FCC License information. For your convenience, we
in any area of Electronics involving communications. In will try to have a representative call to assist in course
some fields, federal law requires that you must have one. selection. Mail reply card or coupon to CIE ... or write:
And, even in careers where a license is not required, it is Cleveland Institute of Electronics, Inc., 1776 East 17th
Street, Cleveland, Ohio 44114. Do it TODAY.

G.I. Bill benefits

, FCC LICENSE
I's 1
All CIE career courses are approved for educational bene-
fits under the G.I. Bill. If you are a Veteran or in service
now, check box for G.I. Bill information.
WARRANTY OF SUCCESS
CIE warrants that when you enroll in any CIE course which includes FCC
r l
License preparation, you will, upon successful completion of the course and CIECleveland Institute of Electronics, Inc.
the FCC License material, pass the Government FCC Examination for the 1776 East 17th Street. Cleveland, Ohio 44114
Accredited Member National Home Study Council
License for which your course prepared you. If you do not pass the appro-
Yes, want your FREE school catalog and career information
I
priate FCC Examination, you will be entitled to a full refund of an amount 1 package today.
equal to the cash price for CIE's "First Class FCC License Course," No. 3. PE-86
Iam especially interested in:
This warranty will remain in effect from the date of your enrollment Electronics Technology Industrial Electronics
to 90 days after the expiration `r, u6, of the completion time allowed FCC License Preparation ['Electronics Engineering
for your course. ' Color TV Maintenance Other
Mobile Communications
//

` ; Yj ®
1
Dr. G. O. Allen President
Print Name
Address Apt.
jj//,,%y / City
State Zip Age
Check box for G.I. Bill information. Veteran On Active Duty
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CIRCLE NO. 13 ON READER SERVICE CARO

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 tion, the load requirement is less
stringent, with typical values being

Product 275 pF in parallel with 47,000 ohms.

Although most CD -4 cartridges have
the wide frequency response required

Test Reports for playing CD -4 discs, very few of

them can play the highest recorded
levels on stereo discs without distor-
tion. Pickering has taken pains to
eliminate this shortcoming in the new
cartridge to allow it to perform at its
best with all types of discs.
ABOUT THIS MONTH'S HI -FI REPORTS The Pickering Model XUV /4500Q
phono cartridge retails for $139.95.
-
On te,sti ug Pickering's new "second geration" CD -4 cartridge, we found it
to be one of the finest stereo cartridges on the market not to mention its
ability as a superb transducer for playing CD-4 quadraphonic discs. Thus, Laboratory Measurements. We
tested the cartridge in the tonearm of a
it overcomes the "stereo- playing" shortcomings exhibited by many earlier
Garrard Zero 100 record player, using
CD -4 cartridges made in the U. S., which did not equal the tracking ability
the recommended 100 -pF in parallel
and general performance of the same manufacturer's top stereo models.
The second hi-fi product examined this month is Crown's new electronic with a 100,000 -ohm load. The 30 -cm /s,
1000 -Hz tones of the Fairchild 101 test
crossover system.. There has long been a school of thought that passive
record were played with negligible
crossover networks were a significant weakness in conventional speaker
systems. A biamplifier or tr-iamplifier system, with electronic crossover distortion at an extremely low 0.5-
gram tracking force, but we had to go
networks preceding separate amplifiers for the different frequency ranges,
to 1 gram to track the high -level 32 -Hz
is an ideal solution to this "problem." One of the most versatile accessories
we have seen in some time is Crown's VFX2 electronic crossover. Its inde-
portion of the Cook Series 60 test
record. For all subsequent tests, we
pendently adjustable low -pass and high -pass filters can be set to cross over
used the 1 -gram tracking force.
at any frequency between 20 and 20,000 Hz. They can also be connected to
At gram, the cartridge was able to
form a three -way crossover or a band -pass filter. The VFX2 should be an 1

invaluable aid to anyone brewing his own speaker system, as well as to track the 80 -pm (micrometer), 300 -Hz
those wishing to experiment with, loudspeaker crossovers. tones of the German Hi -Fi Institute test
record. This is a very severe test of a
-Julian D. Hirsch cartridge's midrange tracking ability.
No other CD -4 cartridge has passed
this test, and only a couple of the
very finest stereo cartridges have
squeaked by. Even more impressive
PICKERING MODEL XUV/4500Q CD -4 PHON1 CARTRIDGE
was the fact that the Pickering car-
Plays CD -4 and matrix 4- channel records, tridge played the highest level on this
as well as being a superb stereo transducer. record (100 pm) at its maximum rated
tracking force of 1.5 grams.
eration, although their specially The output voltage from the car-
shaped styli actually caused less rec- tridge measured 3.95 mV at a
ord wear at these forces than do ordi- 3.54 -cm /s velocity, which is a relatively
nary ellliptical styli operating at 1 gram. high level for a CD -4 cartridge. That
Pickering's "Quadrahedral" stylus this output performance was identical
assembly has a built -in hinged brush for both channels is a very unusual
that removes dust from the surface of occurrence in our experience. The
the record. This brush exerts a 1 -gram 1000 -Hz square -wave response of the
upward vertical force that must be CBS STR -111 test record revealed a
cancelled out. To do this, you just set single cycle of ringing at about 10,000
the downward vertical force to 2 Hz. The output distortion was checked
In the company's grams to yield a 1 -gram net tracking with the aid of two Shure test records.
ciHIRSCH-
HOUCK own words, the force on the record's grooves. Other The TTR -102 is a conventional IM (in-
Pickering Model stylus assemblies for playing mono termodulation) distortion record, con-
XUV /4500Q is a LP's and 78 -rpm discs are available taining 400- and 4000 -Hz test tones re-
"second- genera- from Pickering, and they can be inter- corded at velocities up to 27.1 cm /s.
tion" discrete phono cartridge that changed with the Quadrahedral. The IM measured 1.5% at all levels
is designed to play all types of mono, As is the case with most CD -4 car- except the highest where it reached
stereo, matrixed, and CD -4 records at tridges, the output of the XUV /45000 2.5 %. This is not only exceptionally
a very low -gram tracking force. In
1 must be operated into a low - low distortion, but it also indicates
short, this is a universal -program car- capacitance load (100 pF or less in a very good contact between the sty-
tridge. The "first generation" of CD -4 parallel with 100,000 ohms) to obtain lus and the record groove walls at lev-
cartridges required at least 1.5 or 2 the full 50,000 -Hz response of the car- els that cause most pickups to lose
grams of tracking force for proper op- tridge. For 2- channel stereo opera- contact on modulation peaks.
68 POPULAR ELECTRONICS

www.americanradiohistory.com
 L
PICKERING
CBS
xUV/45000
STRI00

5dB
1000 -Hz square wave.

The TTR -103 test record has spe-

0000
cially shaped 10,800 -Hz tone bursts at FREQUENCY (Hz)
a 270 -Hz repetition rate, with veloci-
ties from 15 to 30 cm /s. The 270-Hz parallel with 47,000 ohms. The low - range provided an ideal complement
content of the cartridge's output is an frequency tonearm/phono cartridge to the falling response of most
indication of the high- frequency non - resonance had a "double- humped" speaker systems in this range. At all
linearity of its tracking performance. shape with the maxima at 5 and 6.5 Hz times, the sound was smooth.
In this test, the cartridge was compar- and an amplitude of only 4 dB or less. This is one of the most expensive
able to the best stereo cartridges on These figures, of course, might be dif- phono cartridges on the market and,
the market and distinctly superior to ferent with other tonearms, but they as such, is obviously intended for a
the average for CD -4 cartridges. are essentially what we would expect select listening audience. Offsetting
Next, we measured the frequency from a high -compliance cartridge. the high price is the fact that this car-
response of the cartridge from 1000 to tridge is one of the very few that can
50,000 Hz with a JVC TRS -1005 test User Comment. Our 4- channel lis- deliver flawless CD -4 performance at
record. The response was exception- tening tests were conducted with a the maximum inherent fidelity in the
ally uniform, varying by only -±3 dB in Panasonic Model SE-405H CD -4 de- program at a 1 -gram tracking force.
one channel and ±1.5 dB in the other modulator. In general, we feel that the Add to this the cartridge's ability to
channel over the full range. The chan- Pickering cartridge delivered quad- track the highest levels on stereo discs
nel separation reached a minimum of raphonic reproduction that was at without significant distortion and the
15 to 20 dB in the vicinity of 10,000 to least as good as, and usually better bonus of extremely low record wear.
12,000 Hz. It was typically 25 to 30 dB than, we have heard from our CD -4 We were impressed with the close
at the lower and higher frequencies. records with any other cartridge. matching of such impo'tant operating
When the audio frequency response With stereo records, the cartridge characteristics as output level, fre-
of the cartridge was checked with the was easily the peer of today's finest quency response, crosstalk, and dis-
CBS STR -100 record, the output was and most advanced stereo cartridges. tortion between the two channels. All
flat to within ±2 dB from 40 to 20,000 The most heavily modulated record- things considered, we must agree with
Hz. In this range, the frequency re- ings played without strain at only 1 Pickering's claim that the XUV /4500Q
sponse was not changed measurably gram of tracking force, and the slightly represents a genuine advance in car-
when we changed the cartridge load elevated signal output from the car- tridge performance.
to the typical stereo load of 335 pF in tridge in the 10,000 -to- 12,000 -Hz CIRCLE NO. 65 ON FREE INFORMATION CARD

Some years ago,

CROWN MODEL VFX2 ELECTRONIC IRSCH-
HIRSCH- before the ad-
CROSSOVER STEREO SYSTEM vent of stereo-
phonic sound
Features active IC filters and continuously and solid -state
variable crossover from 20 to 20,000 H. electronics, there was considerable
interest in electronic crossover sys-
tems among audiophiles who built
their own speaker systems. The cross-
over systems were designed to be in-
stalled between the preamplifier and
the power amplifiers that drove the
appropriate portions of the speaker
system. This permitted the listener to
vary crossover frequencies over a
wide range (not practical with fixed
networks) and eliminated subtle dis-
tortions thought to have been created
by crossover network components in
the speaker system.
As stereo sound came into being,
SEPTEMBER 1975 69

www.americanradiohistory.com
 the development of small and rela-
tively inexpensive high -quality
speaker systems eliminated most of
the incentive to home -brew speaker
systems. Most modern speaker sys-
tems do not provide electrical access
to their individual drivers. Fortunately,
there are a few systems that do pro-
vide such access, and when they are Back panel of network.
used with one of the new electronic
crossover systems now being mar- inputs by about 15 dB. Each low- and knobs. The steep slopes also make the
keted, they make excellent choices for high -pass filter section has two out- crossover filter highly suitable for
bi- and triamplification systems. One puts, one that is in -phase with the conventional audio filtering applica-
of the new electronic crossover sys- input and the other that is 180° tions, and the continuously variable
tems available is the Model VFX2 from out -of -phase with the input. Slide cutoff frequencies can easily be ad-
Crown International. switches for each channel can be used justed to suit the program.
The Model VFX2 contains two inde- to connect the two filter sections for For distortion and output level tests,
pendent but identical signal channels, parallel input, the normal method for we set up the crossover system as a
each of which employs active electronic crossover applications, or 20 -to- 20,000 -Hz bandpass filter, using
operational -amplifier IC filters in low - in tandem for use as an adjustable the unity -gain inputs. The output
and high -pass configurations. The bandpass filter. clipped at 9.7 volts into a high -
cutoff slopes of the filters are fixed at By patching the signal between impedance load and exactly at the
18 dB /octave. Each filter, of which channels, the system can be used as a rated 6.4 volts into 600 ohms. The gain
there are two per channel, has a step three -way crossover system for tri- was unity (1), except through the bal-
switch, supplemented by a continu- amplification. In this mode, two anced inputs, where it could be in-
ously variable control, to permit ad- crossover systems are needed for creased by as much as 16.5 dB.
justing its 3 -dB down frequency over a stereo operation. Another function, Somewhat unconventionally, the
full 20 -to- 20,000 -Hz range (as well as suggested for Crown amplifiers but screwdriver adjustment controls on
providing a flat frequency response). also suitable for many other amp- the rear apron, labelled LEVEL, in-
The crossover system is physically lifiers, makes use of the normal and crease the gain as they are turned
compact. It is designed for standard inverting outputs to drive the amplifier counter -clockwise. The output noise
rack mouting and measures 19 "W x inputs and create a mono signal at a level was well below the 100 -0
53/4'D x 31/2"H (48 x 15 x 9 cm) much higher power level across the minimum indication point of our
and weighs 6 pounds (2.7 kg). Retail two "hot" output terminals of a stereo meter, which corresponds to 88 dB
price is $249. power amplifier. below 2.5 volts.
The comprehensive instruction The distortion of the system can be
General Information. The front manual that comes with the crossover measured, even approximately, with
panel control complement consists of system includes curves that illustrate only the most advanced test equip-
a switch and control for the high- and the typical phase and frequency ment. With the Crown IMA intermodu-
low -pass filters in each of two chan- charactistics of the filters, as well as lation analyzer, the IM readings were
nels. The only other control on the complete specifications and technical the residual of the instrument at
panel is the POWER switch.

-
data. The maximum unclipped output 0.001% up to 1 volt output. It increased
is rated at 10 volts into a high - to 0.003% at the rated 2.5 volts and to
IIIIII
MIMI
CROWN VFX2
TRIAMPLIFIER MODE
CROSSOVERS
200Hz
impedance load, and the low output 0.07% at 8.5 volts output, which is just
INIIIII impedance makes it possible to de- below the clipping level. The 1000 -Hz
NMI
IIIIII 111111.. 111111
CROSSOVERS
500Hz 5kHz
SkHz
velop 6.4 volts rms across 600 ohms.
The rated output of the system, with
THD was less than the noise level up to
0.5 volt, measuring between 0.004%
typical Crown conservatism, is 2.5
111111WASNIli1l NOME and 0.008% from to 9 volts output.
111111 /I x:1141,1 \ 9111111 I
1

volts, with hum and noise stated to be

IIIIIIr/I 021111111i%11111!
MAIM FIISINIIIIIIMIIIIIIRI
100 dB below 2.5 volts. The IM distor- User Comment. It is hardly neces-
tion is rated at less than 0.01% at 2.5 sary to comment on the electrical per-
IIUIIMmIh1Il YUIIIIIII\'
IIdiIII a1111!INV
20 50 100 200 500
FREQUENCY
K
IN Hz
2K
N111111
5K
1
10K 20K
volts output. The unity -gain inputs
have 1- megohm impedances, and the
formance of the electronic cross-
over system, which could hardly be
balanced inputs are rated at 20,000 more ideal with respect to frequency
On the rear apron are 12 phone ohms (10,000 ohms from either side to response, distortion, and noise
jacks that give complete access to all ground) impedance. characteristics. To determine how
parts of the crossover system's cir- well the system performed its in-
cuitry. A functional block diagram is Laboratory Measurements. The tended functions, we connected it be-
silk- screened onto the panel to clearly filters have ideal shapes, with identical tween a preamplifier and two power
illustrate how the signal is modified by gains above and below the crossover amplifiers in a biamplifier setup. Lack-
plugging it into any of the jacks. Each frequency, no passband ripple, an in- ing any speaker systems designed for
channel has separate unity-gain and tersection within 0.5 dB of the ideal biamplification, we combined two
balanced (transformerless) inputs. -3 -dB response point, and a cross- full -range systems, using one as the
Screwdriver controls can be adjusted over frequency generally within 10% "tweeter" and the other as the
to increase the gain of the balanced of the value indicated by the control "woofer."
70 POPULAR ELECTRONICS

www.americanradiohistory.com
 Simply varying the crossover fre- signal level at both outputs and one a multiamplifier system is difficult to
quency made dramatic differences in cannot reasonably expect the woofer say with certainty, since there are dif-
the overall sound quality. Needless to and tweeter to have the same effi- fering points of view on the subject.
say, the optimum frequencies will de- ciency. But one thing is certain: if you decide
pend on the specific drivers used. One Setting up the system in a bandpass to go the biamplifier route, the Crown
thing that was immediately obvious configuration, its performance in this Model VFX2 electronic crossover sys-
was the need for gain controls on the filter mode was excellent in every re- tem will give you the utmost in operat-
power amplifiers, not all of which have spect. Of course, this would be an ex- ing versatility and superb electrical
them. The reason for this is that the pensive way of using the system. performance.
crossover system supplies the same Whether or not you can benefit from CIRCLE NO. 66 ON FREE INFORMATION CARO

HEATHKIT MODEL GR -400 DIGITAL COLOR TV RECEIVER KIT including a four -circuit design for im-
proved selectivity. The dual -gate
Ultra -rectangular 17 -inch CRT provides bright, clear picture. MOSFET r -f amplifier is designed for
low -noise performance, high gain,
One is in the power supply, where it and low cross modulation. A dual-gate
regulates the 24 -volt line. Two more MOSFET is also used in the mixer cir-
are in the on- screen readout assembly cuit.
for gating and character generation. Both the vhf and uhf tuners are de-
(If the optional clock is used, the digi- tented for all channels in their respec-
tal system uses a total of three IC's.) In tive ranges. Extensions on the rears of
the -f section are two IC's, one for
i the control shafts of both tuners ac-
wider than usual bandwidth -f am- i commodate code wheels. The plastic
plification and the other for video de- wheels work with three printed circuit
tection. A fixed LC filter in the -f sec-
i board assemblies (two on vhf, one on
tion virtually eliminates the need for uhf) to electro- mechanically decode
future realignment. the channel numbers. Coded voltages
The aft and agc /sync sections each are then fed to the character generator
THE Model GR -400 is the mid -size have an IC to eliminate almost all other board for incorporation into the video
version of three new small- screen active devices. Sound -f amplification
i signal.
color TV receivers being marketed by and detection are accomplished On the character generator board
Heath. This 17" (43.2 -cm) diagonal by another IC. Finally, there are two are three controls and three wire jump-
measurement, "ultra- rectangular" re- IC's on the color demodulator board. ers. Two of the controls permit the
ceiver employs virtually every state - One is for chroma demodulation; the display to be positioned anywhere on
of- the -art feature currently available in other performs all remaining chroma the CRT screen, while the third control
small- screen models, plus a few that functions. can be adjusted for the desired display
are exclusive to Heathkit receivers. By far the most important feature of time. One jumper lets you display the
One of the new "digital" receivers this receiver is its picture tube. It re- numbers on- screen either continu-
on the market, the Model GR -400 fea- places the familiar dot triad format ously or for a predetermined period of
tures on- screen channel numbers. An with three in -line electron guns, a slot- time before they blank out. (The dis-
optional digital clock accessory ted mask, and color stripes. The play automatically activates whenever
(pioneered with the company's top - stripes are surrounded by a negative - the receiver is turned on or a channel
of- the -line Model GR -2000 color re- guard -band black matrix. Further- change is made.) A second jumper al-
ceiver) also places digitally generated more, the tube itself is designed to be lows you to select between four- and
numerals on- screen. operated at higher anode voltage six -digit time display format. The final
The receiver comes as an all - (from a voltage tripler in this receiver). jumper lets you select between
inclusive kit at a retail price of $489.95. The result is brighter pictures with in- channel -only or channel- and -time
This includes walnut -grained cabinet, creased contrast and excellent color display format. The brightness level of
adjustable telescoping vhf antenna, fidelity. the display can be adjusted as desired.
and ring -type uhf antenna. Optional The precision static toroid yoke as- When the display comes on and
items available are the $29.95 Model sembly comes permanently bonded to blanks out, it is simultaneous channel
GRA- 2000 -1 clock kit, $24.95 Model the neck of the picture tube. It is fac- and time (if you are using the clock
GRA -500 -3 pedestal stand, and $21.95 tory adjusted and sealed, which re- accessory and the jumpers are set for
Model GRA- 403 -18 roll-around cart. duces the number of convergence and this format). With the receiver in the
purity adjustments during setup to instant -on mode, the clock is always
General Information. Among the zero. The new tube design has even keeping time, even though there is no
latest features employed in the re- done away with another potential raster.
ceiver are all- solid -state modular as- source of trouble: pins. Metal contacts A welcome convenience feature for
sembly, extensive use of IC's, and the on the base of the tube pressure -mate families that have children who like to
latest in picture tubes. The solid -state with contacts on the tube socket for play with front -panel knobs is the
design keeps energy requirements positive electrical contact. one -button preset picture control
down, while the modular assembly sim- The vhf tuner used in this receiver (PPC) system. Duplicated on a small
plifies kit construction and service. borrows heavily from the top- of -the- panel buried inside the receiver are
Ten IC's are used in the receiver. line Model GR -2000 color TV receiver, the front -panel brightness, contrast,
SEPTEMBER 1975 71

www.americanradiohistory.com
color, and tint controls. You preset Assembly starts off with Book 1, told, we put in about 35 hours of as-
these controls according to your own which covers the details for wiring the sembly time over a period of about two
tastes. Then, whenever you push in 11 plug -in printed circuit board sub- weekends and five week nights. Add
the PPC button on the front panel, it assemblies and the aft board. Each another two hours for doublecheck-
disables the primary controls and board and its components are packed ing all wiring and soldering.
switches their functions to the preset separately to avoid confusion. Note- Finally, working from Book 3, we
controls. worthy is the fact that all IC's and on- performed the initial tests to assure
The receiver has built -in service fea- board transistors plug into sockets, that everything was okay, after which
tures, backed up by Heath's exclusive rather than having their pins and leads we plugged in the circuit board as-
troubleshooter instrument that ac- solder directly to the pads on the pc semblies and made the circuit adjust-
companies the GR -400 as a kit. There boards. The board -wiring portion of ments according to instructions.
is a sound -output jack for operating the assembly procedure took us some When we were finished, we had a pic-
the receiver through a hi -fi system. (A 10 hours to complete. ture that was truly superb.
switch on the tuner bracket lets you Next came chassis and front panel
defeat the speaker when the hi -fi assembly, covered in detail in Book 2. User Comment. Although this is a
hookup is made.) This consisted mostly of putting to- very easy kit to assemble, if you take it
Both 75- and 300 -ohm vhf antenna gether the metal chassis, mounting in bite -size pieces, it does require
inputs are provided. The 75-ohm input the circuit board connectors and the considerable time to complete. But
is for direct feed with low -loss Coaxial few chassis-mounted components, when you are finished with assembly
cable, such as from a CATV or an and interconnecting the factory - and tuning, you are rewarded with a
MATV system. The 300-ohm input has prepared wiring harnesses in the main picture quality that is second to none.
built in Balun coils for proper imped- chassis. It also included the putting The pictures provided by this re-
ance match between receiver and together and wiring of the tuner ceiver are indeed brighter and sharper
twin -lead transmission line. bracket subassembly and the wiring of than was possible with old receiver
the three identical pc boards that technology. In fact, the brighter,
About the Kit. This was a very simple make up the decoder for the character sharper picture and ultra -rectangular
kit to assemble. We see no reason why generation system. The metal parts screen design make this receiver ap-
a rank amateur to electronic kit build- that make up the chassis went to- pear larger than it really is. We proved
ing could not assemble it, assuming gether without our having to force this in a side -by -side comparison with
that he follows the soldering and as- screw holes and panels to line up. By a large- screen console.
sembly instructions carefully. This is the time we finished this portion of We particularly like the PPC system.
due in no small part to the excellently the assembly, another 18 hours had From a service point of view, the mod-
written and profusely illustrated as- passed. ular assembly and slide -out chassis
sembly manuals. Some credit must Another five hours were spent on permit easy access to every point in
also be given to the modular design picture tube mounting and final as- the receiver's circuitry.
and the fact that very few of the com- sembly. A separate assembly manual In summation, this is a first -class
ponents in the receiver mount on the details this portion of the assembly color TV receiver, well worth the effort
chassis. Also, the high -voltage as- procedure. of assembling it from a kit.
sembly and both tuners come factory We spent another hour assembling
wired and tuned. the troubleshooter instrument kit. All CIRCLE NO. 5 ON FREE INFORMATION CARO

REALISTIC MODEL PRO -6 PORTABLE SCANNING RECEIVER provided for hanging the receiver on a
Scans, four crystal-controlled frequencies in low or high hands. belt. Crystals and batteries can be in-
stalled through separate covered
compartments. A 2" (5.1 -cm) loud-
the very compact portable Realistic speaker is built in for completely self -

tilt
VNF++,-Lo
Model PRO -6 scanning receiver. It is contained operation.
cN,z
designed to receive up to four Resembling a CB walkie- talkie, the
crystal -controlled, fixed -frequency receiver measures a compact 61/2 "L x
channels. The channels can be di- 23/4 "W x 11/2 "D (16.5 x 7 x 3.8 cm) and
vided between the 30 -to-50 -MHz low weighs only about 12 ounces (0.37 kg).
and 148 -to- 174 -MHz high bands. Any It retails for $119.95, which includes
single channel can be continuously earphone, antenna, and batteries.
monitored, or the receiver can be set Crystals do not come with the receiver
to scan any or all of the four channels, and are not included in the retail price.
at a rate of six channels per second. This is because crystals must be
The receiver is powered by four pen- selected according to the specific fre-
light cells. It also has a jack for con- quency allocations in the listener's
necting any suitable external 6 -volt dc area.
power source. A second jack, located
next to the first on the side of the re- General Description. All operating
NRESPONSE to the growing ceiver, is provided for connecting a controls are located on the top
1 popularity of vhf narrow -band FM charger when nickel- cadmium bat- panel of the receiver's case. The
monitoring, Radio Shack is marketing teries are installed. An attached clip is vol_uME- control /power- switch and the
72 POPULAR ELECTRONICS

www.americanradiohistory.com
 Our new cartridges
SQUELCH control are thumbwheel op-
erated. Four light- emitting diodes
(LED's) are provided, one assigned to
each of the four channels. They come
on sequentially as the scanner stops at will turn your
good record player into
each channel. Four slide switches are
used to lock out any unwanted chan-
nel or channels from the scanning se-
quence as desired. A separate toggle
switch has positions to put the re-
ceiver into the scanning mode or to
a great record player.
manually advance one channel at a
time (in the same sequence as on Perhaps you've tried to track your stylus. It safely tracks your records at
scan). records at the lowest advertised setting up to 2 grams while maintaining re-
for your elliptical stylus. In the hopes sponse to 45,000 Hz, offering great
As with other scanning receivers, of optimizing performance and reducing stereo separation, and reducing record
this monitor begins to scan when the record wear. But every footstep threat- wear ... even compared with an ellipti-
SQUELCH control is advanced to the ens to bounce the stylus out of the groove. cal stylus at less than a gram.
And big crescendos are simply fuzzy. Put an Audio -Technica Dual Mag-
point where interstation hiss drops Should you get a better player? No. net* UNIVERSAL cartridge with gen-
out. It stops scanning when a signal is Get a better stylus. uine Shibata stylus in your good old
detected on any of the channels. We have a sensible new approach. A record player today. It's a great com-
stylus shape that contacts more of the bination for better sound today and
When the transmission ends, scan- groove wall, to spread tracking force tomorrow, and tomorrow.
ning resumes after about a one - over a greater vertical area. The Shibata
second delay.
Two miniature phone jacks are pro-
vided for the antenna and private -
AT75Sa
UINIIIVCIZSALM
listening earphone. Built into the re- AT12S AT14SA AT20SLa
T.M. Audio- Technica. Dual Magnet
cartridges are protected by U.S.
Patent Nos. 3,720,798 & 3,761,847.
ceiver is a loop antenna that is suitable Shibata stylus Patent No. 3,774,,918.
for reception where transmitted sig-
nals are strong. Better reception can
be obtained in areas where the signals
are not so strong by use of the external
audio technicao
AUDIO -TECHNICA U.S., INC., Dept. 95P, 33 Shiawassee Ave., Fairlawn, Ohio 44313
Available In Canada from Superior Electronics, Inc.
20" (50 -cm) wire antenna. For best re- CIRCLE NO. 9 ON FREE INFORMATION CARD

sults, a mobile whip or a fixed -station

antenna is advisable. (An antenna of
about 36 ", or roughly 1 meter, in length
is preferable for low -band reception.)
The receiver features a double -
conversion superheterodyne design.
The first conversion is to a 10.7 -MHz
ilitlnlosh
CATALOG
i-f, while the second is to a 455 -kHz -f.
i and FM DIRECTORY
Separate front ends are employed for information McIntosh
Get all the newest and latest on the new Sol-
id State equipment in the McIntosh catalog. In addition you will
the low and the high bands. Each front receive an FM station directory that covers all of North America.
end has its own r -f amplifier, mixer,
and oscillator. Except for the input
and output transformers and the
10.7 -MHz ceramic filter in the -f strip,
i

all of the -f stages are RC coupled.

i

Two integrated circuits are employed

in the scanning section.

Laboratory Measurements. Only

limited laboratory measurements
were possible on the receiver. The MX 113
input impedance is not stated in the FM /FM STEREO AM TUNER AND PREAMPLIFIER
manual, but with a 50 -ohm resistor
McIntosh Laboratory, Inc.
connected across the antenna jack, 20
East Side Station P.O. Box 96
dB of quieting required an input signal Binghamton, N.Y. 13904
level of 2.5 to 3 kV on both the low and
the high bands.
SEND Dept. PE

Signal deviations of at least 11,000 NAME

Hz could be accommodated without
serious distortion. (The rated devia-
TODAY! ADDRESS
CITY STATE ZIP
tion is ±7000 Hz maximum.) The
squelch threshold could be adjusted If you are ina hurry for your catalog please send the coupon to McIntosh.

from less than 3 to greater than 201.N. For non rush service send the Reader Service Card to the magazine.
CIRCLE NO. 30 ON FREE INFORMATION CARD

SEPTEMBER 1975 73

www.americanradiohistory.com
 Your NEW Heathkit
H
`a``= Catalog
is ready
waiting to serve you with
more values, more new
kits, than ever before
Now over 400 do- it- yourself electronic kits
for home, hobby, and industry. All designed
lew - Two -Way
Telephone Amplifier Kits
to give you more for your money...more Now, hands -free telephone use with ampli-
value, more performance, more satisfac-
tion. All designed so even beginners can
-
fied "talk" and amplified "listen" with or
without dialer. Talk & listen from 10' away.
build them. Send for your free catalog Voice -actuated circuitry switches from talk
today. to listen without feedback or clipped words.
Listen button lets you monitor line without
built -in microphone activated. Dialer model
may be used with or without regular tele-
phone. Includes 4 -prong jack & phone
coupler connector. Battery powered. Kit
view Programmable GD -1112 (no dial) $49.95; Kit GD -1162 (w.
dial) $69.95.
©eon e Digital Stop Watch Kit
J\j ew Professional Another "first" from Heath. 2 IC counters,
8 digits & 7 functions with typical accuracy J%J ew Public
12" Ignition Scope
Kit or Wired
- to ±0.003% and resolution to 1 /100th of a
second. Function 1 (Start /Stop Elapsed)
times individual events while also counting
Address
Sound System
total. Function 2 (Sequential) times each
Does more than others for $1000 less. part of event & displays each separately Kits
Spots tough ignition problems on all types while timing overall event. Function 3 (Total Outperforms those
of systems in 3, 4, 6, 8 cyl. or 2 -rotor Wan- Activity) accumulates total elapsed time costing twice as much.
kel engines; sets itself automatically for no. of a series, excluding time between events. TA-1620 Control /Amp.
of cylinders. Big 12" screen has 2 cali- Function 4 (Split) displays cumulative time takes 6 low imped-
brated primary and secondary voltage to each "split" point while continuing over- ance mikes, each with
grids plus dwell angle indications. Special all event time. Function 5 (Start /Stop Ac- level, bass & treble
circuit maintains trace length regardless tivity) shows separate time for each event controls & reverb sw.
of RPM. Displays "superimposed" patterns, & totals all individual times. Function 6 Has VU meter, 4
single cyl. pattern, primary or secondary (Programmed Upcount) counts up to switched response
"parade" patterns. "Power balance" fea- "learned" time. Function 7 (Programmed "shaper" circuits, ex-
ture even helps spot bad valves or rings. Downcount) counts down from "learned" clusive bass filter, 100
8" meter with tach & DCV ranges. Optional time. Stop watch can "learn" time from rms watts drives 2
low cost timing light, alternator adaptor & other functions or be programmed up to speaker columns. TA-
cart. Kit CO -2500 $379.95; Assembled WO- 9 hours, 59 minutes, 59 seconds. Has jacks 1625 Booster Amp.100
2500 $695. for external triggering devices and alarms. rms watts to drive 2
Includes nickel- cadmium batteries & extra speaker col-
charger. Kit GB -1201, $99.95. umns. TS -1630 Speak-
er Column. Six 8" full -
range drivers re-
sponse tailored for
voice; 60 watt rms rat-
ing; 12 ohm imped-
ance. Kit TA -1620
$449.95; Kit TA -1625
$179.95; Kit TS -1630
$199.95.

Js.1
ei/ Automobile
Intrusion Alarm Kit
Pew Digital Wind Speed
Direction Indicator Kit
&
Unique. Two big, bright digits show wind
Total Protection. Alarm mounts anywhere; speed to 99 mph. As you build, choose 2
connects to switches on doors, hood, & readout modes: miles, knots, or kilometers
trunk. Underdash switch arms or disables per hour; front panel light shows mode in
unit. Adjustable delay time allows you to use. 8 incandescent lights show wind direc-
quickly enter or leave car without trigger- tion at principal compass points; adjacent
ing alarm, but opening trunk or hood trig- lighted bulbs give 16 point resolution. Re-
gers alarm instantly. Alarm sounds car mote transmitter boom clamps to TV mast.
horn in repeated 2- minute cycles. Kit GD- Styled in black plastic to match Heathkit
1157 Alarm $24.95; Kit GDA- 1157 -1 Siren GC -1005 Digital Clock and ID -1390A Digi-
(gives yelping sound louder than car horn) tal Thermometer. Kit ID -1590, $69.95 less
$19.95. cable.
74 POPULAR ELECTRONICS

www.americanradiohistory.com
 H I

cJ
Nei/ Variable
Isolated AC Supply
J4,I ew Oscilloscope
Calibrator Kit
ew DC -5 MHz What every tech & hobbyist needs. The For time calibration, it generates a 0.5
JI-riggered Scope
Kit or Wired
- IP -5220 isolates equipment under test from
the AC power line and provides an AC out-
put which is variable from zero to 140 volts.
second to 1 µsec square wave in 1 -2 -5
sequence accurate to 0.01% with 200 mV
peak K3% overshoot) and <4 ns rise
Great for locating circuit faults caused by time. Voltage calibration ranges are 1 mV
Best scope value today. Wide bandwidth,
20 mV sensitivity, & stable triggering
ideal for TV, audio and RF servicing. Easy -
- high or low voltage or testing equipment
with unknown power requirements. Power
to 100 v. in decade sequence, accuracy
within 2 %, DC plus variable 2 Hz to 10 kHz
rating is 360 volt- amperes, continuous. in 1-2 -5 sequence (internal stnd. accuracy
to -use controls. Trigger circuit (not recur- Variable output current rating: 3A. max. within 1 %). Use it to calibrate scopes up
rent type) has normal & automatic modes, Direct output curent rating: 10A. Two to 35 MHz and voltmeters; it's also a fast
switched AC & DC coupling, & front panel meters: voltmeter 0 -150 VAC; ammeter: rise time squarewave generator and good
external inputs (special TV position allows 0 -1 & 0 -3A. Ammeter and variable output bench freq. standard. Kit IG -4505 $44.95
low freqs. to pass while rejecting high socket are fused. Kit IP -5220, $109.95
freqs. for easy triggering on complex TV
signal. 7 calibrated time bases from 200
ms to 0.2 µs /cm. 20 mV /cm vertical sensi-
tivity with 9 calibrated attenuator positions
up to 10 v /cm, plus variable control. 5"
round flat -face CRT (8 x 10 cm graticle).
Lightweight, durable blue plastic cabinet
with white panel. Kit 10 -4540 $179.95;
Assembled SO -4540 $275.

21 " (wag.)

y
elVew
Digital Design
Color TV Kit
All the advanced technology
of digital circuitry in a small-
er screen size. Electronic
touch -to -tune varactor front
end (nothing mechanical to
wear out) with computer-like
programming board for up
to 16 channels. On- screen
channel numbers, adjustable

JI ew - Lowest cost
in brightness, position, and
duration. On- screen digital
clock; a low -cost option; pro-
Triggered 5 MHz Scope Kit grammable in 12 or 24 hour
The scope everyone can afford, and it has format, displays 4 or 6 digits.
the performance you need. DC -5 MHz band
width, 100 mV vertical sensitivity with X1,
Fixed -filter IF, a Heath exclusive that
assures better pictures longer, never needs
-
Easier to build & service thanks to ex-
tensive modular design and built -in servic-
X10 & X100 attenuation, AC or DC. Auto- instrument alignment. 100% solid state
more ICs than any other -
sophisticated
- ing tools including digital- design dot
generator, front access slide -out Service
matic, positive locking horizontal sweep
continuously adjustable from 20 ms to 200 circuitry that results in less interference, Drawer, new picture centering and pin -
ns /cm. Stable displays due to zener regu- better color tints, improved sensitivity, cushioning correction circuits, and Test
lated amplifiers and sweep. 5" round flat -
face CRT with 8 x 10 cm graticle. Simpli-
greater noise immunity, improved picture
definition. Black negative matrix 21V pic-
Meter. Enjoy the best in TV design - now
in smaller size at lower cost. Kit GR-2ò50
fied controls and switches make it easy to ture tube for brighter, sharper pictures. $599.95. Kit GRA- 2000 -6, remote control,
use. Lightweight, durable blue plastic cabi- Total touch -tune remote control -low cost $89.95. Kit GRA- 2000-1, digital clock ac-
net; white panel. It's the best instrument option that operates all functions, includ- cessory, $29.95. Contemporary or Mediter-
buy in years. Kit 10 -4560 $119.95 ing recall of time & channel. ranean cabinets from $119.95.

New catalogs Use coupon below to order your favorite new kit
and kits
also available at or to get your FREE new Heathkit Catalog.
HEATHKIT ELECTRONIC CENTERS - r HEATH Heath Company 1
Units of Schlumberger Products Corporation Dept. 10-09
Retail prices slightly higher. Schlumberger Benton Harbor, MI 49022
Please send my free 1975 Heathkit Catalog.
ARIZ.: Phoenix; CALIF., Anaheim, El Cerrito, Los Angeles, Pomona, Redwood
City, San Diego (La Mesa), Woodland Hills; COLO.: Denver; CONN.: Hartford Enclosed is $ plus shipping.
(Avon); FLA.: Miami (Hialeah), Tampa; GA.: Atlanta; ILL.: Chicago, Downers Please send model(s)
Grove; IND.: Indianapolis; KANSAS: Kansas City (Mission); KY.: Louisville; LA.:
NAME
New Orleans (Kenner); MD.: Baltimore, Rockville; MASS.: Boston (Wellesley);
MICH: Detroit; MINN.: Minneapolis (Hopkins); MO.: St. Louis (Bridgeton); NEB.: ),nOn_i5
Omaha; N.J.: Fair Lawn; N.Y.: Buffalo (Amherst), New York City, Jericho (L.I.),
e1T
Rochester, White Plains; OHIO: Cincinnati (Woodlawn), Cleveland, Columbus,
Toledo; PA.: Philadelphia, Pittsburgh; R.I.: Providence (Warwick); TEXAS: " "` " " `" " °R° MAC 1.0 r. CL-571 J
Dallas, Houston; VA.: Norfolk (Va. Beach); WASH.: Seattle; WIS.: Milwaukee.
CIRCLE NO 5 ON FREE INFORMATION CARD
SEPTEMBER 1975 77

www.americanradiohistory.com
The audio frequency response, rela- Weather Transmissions on 162.55 good, and received signals had excel-
tive to the 400 -Hz input, varied by ±6 MHz and several fire and police chan- lent clarity and intelligibility.
dB between 230 and 4000 Hz. Into a nels employed in the metropolitan The PRO -6 should prove to be ideal
16 -ohm load, such as the accessory New York area. No transmitting sta- for receiving local Civil Defense units,
earphone, the maximum undistorted tions were nearer to our listening loca- volunteer fire department calls, etc.
output power was 62 mV. tion than 10 miles (16 km) and several For these purposes, its light weight
were at least 20 miles (32 km) away. and compactness provide a big ad-
User Comment. We fitted our test We heard strong signals on all vantage.
receiver with crystals for the NOAA channels. The audio volume was CIRCLE NO 68 ON FREE INFORMATION CARD

HICKOCK MODEL 440 TRANSISTOR CURVE TRACER

tracer was in.troubleshooting. We had
Identifies and niatche transistors hy displaying characteristic curves. on our bench an expensive oscillo-
scope that had resisted all of our ef-
forts to repair. We had not had a curve
the transistor mode, this function dis-
tracer to help us, although we did
plays a single full -range I, /I
curve
know that one transistor of a differen-
from which ac and dc beta can be in-
tial pair was bad. We replaced that
stantly determined. This curve also
transistor, but there was still a prob-
shows beta linearity at a glance.
lem with stability.
Switching to the FET mode, the
Since we now had on hand a transis-
Insta -Beta function displays the entire
tor curve tracer, we pulled both the
transfer curve, including pinch -off
good transistor and the supposedly
voltage (V,,), full -on current (IDy,),
exact replacement transistor and ran
and the active portion for easy trans -
an A -B comparison. Both transistors
-c,onductance (G,,,) calibration. had the same 2N numbers stamped on
In conventional semiconductor test-
them, but when their characteristic
ing, the tracer features a variable step
curves were displayed, they were
control that provides up to 10 steps worlds apart in performance. We then
per family. The steps are in base cur- sorted through a number of transis-
AN ORDINARY in /out -of- circuit rent for bipolar transistors and gate
tors until at last we had a matched
transistor tester is sufficient if all voltage for FET's.
pair. Upon installing the pair in the
you want to do is track down a defec- A horizontal volts /division control is
scope and performing the recom-
tive transistor. But when you have to provided for changing oscilloscope mended tuning, the scope worked
identify an unlisted or unmarked sensitivity without having to recali- perfectly.
transistor by its performance charac- brate the scope. The maximum sen- Our scope problem is just one type
teristics or to match two devices of the sitivity of V /division is especially use-
1
of job the curve tracer can tackle in
same type, there is no substitute for a ful for measurements in the semicon- short order in a service shop. Another
transistor curve tracer. ductor threshold or turn -on region. job is identifying transistors marked
While the simple go/no -go tester is a The collector supply is variable from with foreign numbers in imported
self- contained instrument, the curve zero to 100 volts peak via a knob on the radios, recorders, etc., according to
tracer must be used in conjunction curve tracer's control panel. performance characteristics. The
with an oscilloscope to display a fam- A pull -out card at the lower edge of method of identification is to run A -B
ily of characteristic curves for the the instrument's front panel provides comparisons with domestic transis-
semiconductor under test. One such a ready reference for information for tors until you find the proper substi-
instrument recently put on the market calibration, setup, and operation of tute. Of course, a transistor manual
by Hickock Electrical Instrument the curve tracer. helps enormously for this operation by
Company is the Model 440 transistor Two transistor sockets on the con- providing families of curves that
curve tracer, retailing for$165. trol panel provide a convenient means match those displayed for the un-
This instrument performs the usual for testing and matching devices by known transistor.
curve tracing functions for ger- the A -B comparison method. The The curve tracer is an extremely
manium and silicon bipolar signal and sockets are supplemented by two sets useful tool for sorting through a col-
power transistors. In addition, it can of color -coded banana jacks for in- lection of unmarked or house -marked
also test FET's, SCR's, UJT's, and circuit tests and for connecting physi- devices. We quickly sorted through
signal, switching, rectifier, and zener cally large transistors to the curve several semiconductor devices we
diodes. tracer for out -of- circuit testing. All op- have been collecting. Transistors
The 41/4 -pound (2 -kg) transistor erational controls are clearly labelled were graded according to type, beta,
curve tracer measures 81/4" W x 71/2" D as to function and setup. Fast setup etc., and diodes according to type
x 45/8"H (21 x 19 x 12 cm). positions on the legends for each con- (silicon or germanium and signal or
trol are marked by small arrowheads rectifier) and, for zeners, according to
General Information. The curve when the user does not know the ac- voltage. We even found a few expen-
tracer has a unique feature, which tual starting parameters. sive FET's in the collection. In this one
Hickock calls "Insta- Beta," that takes instance alone, the curve tracer more
the guesswork out of transistor beta User Comment. The first test to than paid for itself.
and FET parameter calculations. In which we put the Model 440 curve CIRCLE NO. 69 ON FREE INFORMATION CARD

78 POPULAR ELECTRONICS

www.americanradiohistory.com
 ing with a scope and an r -f circuit to be
swept, turn on the sweeper's vfo and
tune the birdie. Then turn on the

Test Equipment crystal oscillator to a frequency that is

within the swept range and note its
birdie. Operate the vfo dial until you

Scene get a zero beat between the two bir-

dies. The vfo dial should now indicate
the exact frequency of the selected
crystal. If not, you can make the
By Leslie Solomon necessary adjustments to the vfo dial
CHECKING THE SWEEP GENERATOR "BIRDIE" so that it is correct. You can use har-
monics of a crystal or higher -
THERE are many uses for sweep play on the scope. This will be frequency crystals to check the other
generators in aligning FM, TV, (roughly) the fundamental frequency ranges of your sweeper.
and other r-f systems. Most of these
sweepers include some form of
of the crystal (despite what it may say
on the box). Now couple the frequency
4MONTHOFSPECIALS
THE 4ACE

t.
variable- frequency oscillator to pro- counter to-the r -f generator; and, as
duce the "birdie" markers used to you carefully tune for maximum
identify particular points along the
viewed trace.
waveform display on the scope, note
and record the frequency. Use a felt -
.m. . r.,wl
e';BId! e Qn,e,tl,q'ütY.Yl,le'E
--,11;11D ,

6
I.r

'we:'èlnl:ete,"ee,ee,m,q° 5
Obviously, the more accurate these
marker frequencies are, the more ac-
tipped marker pen to identify each
crystal. As we said, however, this is a
'öé éé`é!'b'ó rwó' éeái'
I,

á'

curate the alignment. So, the question rather rough frequency value; so it is ASCii COMPUTER KEYBOARDS
These keyboards were manufactured for use on Texas
is, just how accurate are your mar- necessary to take one more step to Instrument's line of Silent 700 series data terminals. They are
fully encoded with TTL large scale integrated circuits IT.I.
kers? It should be noted that some refine the value. At least this test has TMS.5000 in 28 pin socket). Additional IC's provide a par -

rallel 7 bit, without parity, code plus a strobe signal indica,

sweeper manufacturers include given you a "ballpark" figure Mg "valid" data and six other independent outputs for those
special keys which are not encoded. The keys are reed type
crystal -controlled frequencies (4.5, 12V
with a format similar to typewriter. Internal circuitry pro-
vides for two key rollover and de-bounce. Output is on stan.
10.7,TV frequencies, etc.), but here we 15K
dard 10 pin double readout connector for data and power in-
put. And 8 pin double readout connector for six special
are discussing those older sweepers switch functions.
KEYBOARDS
that use a vfo and do not have the KB-6 - Clare/Pendar 720627 -1
T.I. Part number 959327-1
crystal -controlled provision. A 56 key ASCii encoded Alphanumeric keyboard
with six extra switch closures to ground marked HERE
Possibly, you have stored away in a IS, PAPER ADV., BREAK. REPEAT, TAPES TAPE.,
code 1 - $47.50 2 - $37.50 3 - $17.50
small cardboard box a number of KB -7 - Clare / Pendar 720731 -1
T.I. Part number 959326 -1 as used on T.I. Silent 700
quartz crystals obtained from long - 8.2K data Terminals. This is a 64 key full ASCii encoded
keyboard.
forgotten CB rigs, ham gear, or old code 1 $4915 2 $39.95 3 - $19.95
1. All keyboards supplied with wiring diagrams, code
test equipment. Here is your chance to tables, and other useful documentation.
determine their frequencies and make PRICE:
1. New - tested and guaranteed w /test record
use of them. 2. Used tested and guaranteed w /test record
3. Used untested - appear to be in good condition.
In the Radio Amateurs Handbook, LSI Chip missing - may have a few bad or broken
switches. Good for parts.
Determining the Frequency. First we found a good transistor crystal - ACOUSTIC COUPLER
you have to make sure just what the oscillator circuit. We built the oscil- This coupler was manufactur
ed by Novation, Inc. Tarzana. Cali
crystals' frequencies are. Despite the lator circuit on a small pc board and fornia for use in Texas Instrument's
model 725 Electronic Data Terminal.
markings that may be on them, many "stole" the required power from the It is compatible with Bell 103 and
crystals have fundamental frequen- solid -state r -f generator we were 113 data sets or equivalent. The
coupler operates asynchronously to a
cies far different. The identification using. maximum speed of 450 baud in the
full-or- half -duplex mode coupled to
process is quite simple. All you need is With the oscillator circuit operating, a standard telephone handset. Trans-
mit freq. is 1270hz for mark and
a conventional r -f signal generator (a we plugged the known good crystals 1070hz for space. Receive frequency
is 2225hz for mark and 2025hz for
sweeper will do if you can tune it man- in and checked the operation on the space. Unit required b 12 VOLTS
ually without sweep), a frequency scope. Then we used the frequency and o 5 VOLTS for operation. Corn
plete with schematic & all pertinent
counter, and a scope. counter to get the exact frequency. information, fully reconditioned, cal -

ibrated, and guaranteed -$59.95.

Connect the signal generator Once we had a decent selection of fre- MEMORY CHIP
ground to the scope's ground. Then quencies, we used a multiple -pole ro-
SN74$201N 256 -BIT RAM
connect the unknown crystal between tary switch for crystal selection and with 3 state output.
Plug in replacement for SN74
"hot" leads of the generator and
. marked the switch with the frequen- 200 & SN74S200.
10 for $25.00
scope. A quartz crystal is a very - cies. Using the same approach as that METER
$3.95 ea.
NEW GUARANTEED
high-Q device, and when the of the vfo within the sweeper, we cou- EMICO Model
ma edgewise meter.
'3 - 0 -1
Scale is TERMS: We pay postage, un
generator is tuned to the frequency of pled the crystal oscillator to the marked 0-10 relative output. less otherwise specified. Or
Mounts in a 3/4 X 1.7/8 rec- dens over 550.00 subtract
the crystal, the scope will suddenly sweeper mixer. tangular hole with a press on 10 %. Include check or money
clip supplied with the meter. order, no COD. Texas resi
display a waveform (should be a sine New
$15.00
- $1.95 each 10 for dents add 5% sales tax.

wave). There will be almost no Tuning the Birdie. If you are lucky,
waveform when the generator is not you will have some good frequencies ELECTRONIC
tuned to the crystal frequency. to use. (Of course, you can always buy PARTS
Starting at a low frequency, tune the a low -cost crystal with a useful fre- 3303 Mangum Road
Houston, Texas 77018
signal generator until you see the dis- quency.) Now, with the sweeper work-
CIRCLE N0. 14 ON FREE INFORMATION CARD
SEPTEMBER 1975 79

www.americanradiohistory.com
 %4`
ACTML,\\
with the romantic name of La Voz de
los Centauros-and then attained its
nominal channel of 5.990.

"AW
DX Nicaragua happens to be a rare
country for shortwave broadcasts, so
DX'ers welcomed the reappearance of

Listening Radio Atlántico, Bluefields, on 6.1182

MHz. The station does have an English
program, but it's during the daytime.
Mexico City's cultural outlet, Radio
Universidad, went to 9.767.2 MHz from
By Glenn Hauser its nominal 9.600 last November, and
then went silent. This summer it re-
ANTARCTICA CALLING
turned, on 9.60945 MHz, facing stiff
interference from the world's most
AFTER a long, hot summer, Radio Australia calls its men in An- distant SWBC station, ABC -Perth, on
how about an armchair tarctica on Fridays GMT at 0300 -0330 9.610 MHz -until the Australian closes
trip to Antarctica? Just a year ago, on 15.290; 0400 -0430 on 15.240; and down at 1602 GMT.
North American DX'ers began picking 0915 -0945 on 6.005 MHz. Radio Mos-
up the American Forces Antarctic cow transmits (in Russian) twice a Publications. The only major club
Network on 6.012 MHz (not to be con- week toward Antarctica -Mondays specializing in SWBC DX news is the
fused with a spur from AFRTS, Ohio and Thursdays at 1530 -1600. Fre- North American Shortwave Associa-
on 6.018 MHz or a spur from HCJB, quencies often change, but try 12.000, tion, Box 13, Liberty, IN 47353. Dues
Ecuador, on 6.012 MHz). Reception of 11.630, 9.510, 9.490 or 7.135 MHz. Now are $12 per year; or send $1 fora sam-
AFAN peaked in October and for the easy ones: BBC designates ple of the monthly journal FRENDX.
November, especially on the West 7.130 MHz exclusively for Atlantic Is- Long- needed and now available is a
Coast around 1100 GMT. Then, last lands and Antarctica, at 2245 -0430 TV Station Guide, with channel -by-
April, from his ideally situated GMT daily, with the same World Serv- channel maps and accompanying ta-
monitoring post at the southern tip of ice programs heard elsewhere. But on bles showing location, call, net,
New Zealand, Arthur Cushen flashed Sundays "Calling the Falkland Is- power, offset (even on UHF!), plus ex-
news of a change for AFAN to 7.050 lands" approaches an Antarctic serv- tensive listings and maps of stations
MHz. It is possible that AFAN may have ice, at 2200 -2245 on 9.915 and 12.040 as far south as Ecuador. You can order
returned to 6.012 MHz, by now. MHz. it for $5 from WTFDA, Box 163, Deer-
DX'ers speculate that other nations Antarctica happens to be in the field, IL 60015.
with Antarctic bases may initiate their same direction as the Caribbean,
own broadcasts since radio news and viewed from Bethany, Ohio, so AFRTS The OSL Flap. Tuning in broadcasts
entertainment help diminish the sense transmissions from there serve both from all over the world is exciting
of isolation. Meanwhile, North Ameri- regions, 24 hours a day, on 6.030, enough -but many DX listeners aren't
can DX'ers can hear, with some effort, 9.755 or 15.330 MHz. satisfied with just hearing a station,
a handful of programs beamed on perhaps taping it, and above all
shortwave from the home country to- Less and Less English? The Voice of knowing they heard it. They want
ward Antarctica. Germany, on April Fool's Day, cut its something tangible to "prove" their
For instance, Radio RSA has a pro- English broadcasts to North America reception. Since it's good public rela-
gram for the South African National from three hours a day to 40 tions, and a way to encourage listen-
Antarctic Expedition, Sundays at minutes -the same amount as Bel- ers to send in reception reports, most
0956 -1045 GMT on 15.220 (alternate: gium. Radio Finland soon launched major broadcasters go along with the
15.155) and 11.970 MHz. Radio New trial balloons on eliminating its En- practice (derived from ham radio) of
Zealand also broadcasts weekly to- glish programs completely and then 'verifying' reports with QSL cards.
ward Antarctica, Sundays GMT at was crippled by a June strike of I have quite a QSL collection myself.
0015 -0045 (that's Saturday evening English -language freelance program They're great for display at conven-
here) on 15.280 MHz. producers. One nation where English tions and make nice, often artistic
broadcasting is secure is Australia. By souvenirs. But a reputable DX'er
Dec. 20, the abandoned U.S. tracking shouldn't really need anything beyond
We are pleased to verify your ret
base at Carnarvon is to become the his word of honor to convince others
on the reception of Radio Can
International. temporary replacement transmitter of what he has heard. In addition, an
Thank you
Canada.
and hest ylelTj, from site for Darwin, which was blown off unhealthy aura can surround these
Noua sommes tr e ureu
the air last Christmas. QSL cards. There is tendency to judge
c: .á
tr epo
na
oute d\116dio
Spanish and Portuguese dominate a DX listener by the extent of his QSL
GLENN HAUSER
Marc'illeure eddu Canada.
1312 W. Oak Latin American airwaves. This year's collection, which is actually an option.
Enid OK big story is the extensive rearrange- And this leads to narrow definitions of
73701 USA
ment of Brazilian frequencies in the just what constitutes a valid QSL.
60- and 90 -meter bands -so don't When Radio Canada International
jump to conclusions by referring to announced that it would cease
Radio Canada has simplified an outdated list. A new Colombian specifying the frequency or any other
their QSL to save money. shortwaver appeared on 5.9618 MHz details on its QSL's, howls of protest
80 POPULAR ELECTRONICS

www.americanradiohistory.com
were heard from avid QSL collectors.
(RCI made the move to cut down its
Could the ultimate system be
operating expenses.) At issue, actu-
ally, is the real purpose of interna- ali Crown ?
tional broadcasting: filling QSL al-
bums or propagating a nation's news It depends on how you define
"ultimate ". But Crown
and image. Would we rather have de- may be the only top-
tailed QSL's or quality programming? quality, state -of- the -art
manufacturer whose
Conventions. Coincidentally, RCI is components could build
a complete ultimate
co- hosting this year's Association of
system.
North American Radio Clubs conven-
For instance: A
tion, in Montreal, Aug. 22 -24. All CX -824 tape deck, world -
DX'ers are cordially invited, though by renowned for reliable
now it's a bit late to secure hotel reser- performance. Connected to an
vations. For details, call (514) 486- IC -150 pre -amp. With the signal
9614. Among many other topics, RCI's amplified by a DC -300A power
amp, proved in many thousands
new QSL policy will be discussed of hours of professional use. Out-
by Ian McFarland, the RCI DX pro- put controlled, monitored and switched
gram producer. by an OC -150. Possibly a VFX -2 for personal
If you're at the other end of the con- control of crossover points. And sound faithfully
tinent over the Labor Day weekend reproduced by ES -212 electrostatic speakers.
(Aug. 29 -Sept. 1), you're invited to All Crown. We think that system would be
somebody's ultimate. Certainly ours. Maybe yours.
drop in for the NORCAL get- together,
Write us today for the name of your nearest
at El Rancho Inn. Millbrae, California.
For information, contact Rick Heald,
Crown dealer. He'll talk to you ultimately. -
17412 Rolando Ave., Castro Valley, CA
94546.

Handicapped Aid. RCI's support of Box 1000, Elkhart IN 46514

both the Canadian and American
CIRCLE NO 16 ON FREE INFORMATION CARD
Handicapped Aid Programs (CHAP
and HAP -US) shows its heart is in the
right place, whatever its QSL policy.
Reel or cassette tapes of RCI's African NEW, FULL-FEATURE-
PERSQNAL 2 -WAY
idents and interval signals series are
available through either group for
$3.50. Tapes covering other regions of
the world are soon to follow.
HAP and CHAP deserve the support
both of benefactors and of handi-
ADIO
capped people already enjoying the
shortwave and DX listening hobbies. If
you know someone whose handicap
has led to a contracting world, you can
help expand it by putting her or him in
contact with HAP, c/o Ted Poling, Box
163, Mt. Sterling, IL 62353; or CHAP,
c/o Harold T. Sellers, 122 Giroux St.,
STYLED FOR THE CB'ER WHO IS BUDGET MINDED,
Apt. 20, North Bay, Ont. P1 B 7Y7. HAP YET WANTS A COMBINATION OF PERFORMANCE,
and CHAP offer to loan SW receiving STYLE AND RUGGEDNESS FOR HIS CB RADIO.
equipment and a half -price DX club
PACE CB 144 is a fully synthesized 23 channel AM transceiver offering full legal
membership to deserving handi- transmit power.
capped applicants. Maximum control at your fingertips: Noise blanker switch Automatic noise imiter
In addition to the tapes, HAP financ- switch RF gain control PA control Delta tune Illuminated S /RF meter transmit
indicator light Plug -in microphone.
ing comes from a translation service Operates on 12V DC ( +) or (-) ground.
and sales of happy -face rubber Suggested retail price $179.95
stamps. CHAP also sells stamps for
See your distributor today.
collectors. When inquiring, please en-
close a self- addressed stamped en-
velope. Regular HAP progress reports
are broadcast on the Saturday DX
programs of RCI and HCJB, and via
Radio Nederland each third Thursday
upn PACE COMMUNICATIONS, Div. of Pathcom Inc..
24049 S. Frampton Ave., Harbor City, CA. 90710, Dept.62

Available in Canada from Superior Electronics Ind. Export, 2200 Shames Dr., Westbury,
N.Y. 11590

of the month.
CIRCLE NO. ON FREE INFORMATION CARD
SEPTEMBER 1975 81

www.americanradiohistory.com
 ENGLISH - LANGUAGE SHORTWAVE BROADCASTS FOR SEPT. & OCT.1975

ALLTYPES OF SPEAKERS, by Richard E. Wood

SPEAKER SYSTEMS AND TO WESTERN NORTH AMERICA

OTHER ELECTRONIC PARTS TIME -POT TIME -GMT STATION QUAL* FREQUENCIES, MHz
SEEK IMPORTER AND
4:00-5:15 a.m. 1100-1215 London, England G 5.99 (via Sackville),
DISTRIBUTOR
11.75 (via Tebrau)
5:15-6:15 a.m. 1215 -1315 London, England F 11.75 (via Tebrau)
6:00-6:15 a.m. 1300 -1315 Tokyo, Japan G 5.99
7:00-7:30 a.m. 14001430 Tokyo, Japan G 9.505
7:00-9:00 a.m. 1400 -1600 * "VOA, G 6.185, 9.565
Washington, U.S.A.
8:00-8:30 a.m. 1500 -1530 Tokyo, Japan G 9.505
9:00-10:15 a.m. 1600 -1715 London, England G 15.365 (via Sackville)
9:42-9:51 a.m. 1642 -1E51 Hilversum, Holland G 15.14, 15.19 (via Bonaire;
(Mon.-Fri.) mixed English /Dutch)
10:00-10:15 a.m. 17001715 Tokyo, Japan G 9.505
11:00-11:15 a.m. 18001815 Tokyo, Japan G 9.505
12 noon-12:15 p.m 1900 -1915 Tokyo, Japan G 15.105
1:00-1:15 P.m. 2000 -2015 Tokyo, Japan G 15.105
2:00-2:15 p.m. 2100-2115 Tokyo, Japan G 15.105
2:15-4:00 p.m. 2115 -2300 London, England F 9.58 (via Ascension)
3:00-3:15 p.m. 2200 -2215 Tokyo, Japan G 15.105
4:00-4:30 p.m. 2300 -2330 Tokyo, Japan G 15.105
4:00-5:30 p.m. 2300 -0030 London, England G 6.175, 9.51 (via Sackville),
9.58 (via Ascension)
5:00-5:15 p.m. 0000 -0015 Tokyo, Japan G 15.105
5:00-7:00 p.m. 0000-0200 " *VOA, G 15.29, 17.895
Washington, U.S.A.
5:30-8:30 p.m. 0030-0330 London, England 6.175 (via Sackville),
9.51 (via Greenville),
CHIEN CHANG INDUSTRIAL 9.58 (via Ascension)
CO. LTD. 5:30-6:00 p.m. 0030 -0100 HCJB, Quito, Ecuador 5.97, 9.56
241 Wanta Road, Taipei 109, Taiwan 6:00-6:15 p.m. 0100 -0115 Tokyo, Japan 15.105
6:00-7:00 p.m. 0100-0115 Peking, China 9.94, 11.945, 15.06
Republic of China TELEX 22416 6:00-8:00 p.m. 0100 0300 Melbourne, Australia 15.32, 17.795
Moscow, U.S.S.R. 12.05, 15.18, 17.775
(via Soviet Far East)
6:00 p.m.-12 mdt. 0100-0700 HCJB, Quito, Ecuador 5.97, 9.56, 11.915
(includes Eskimo)

NICE 16 MT 6:30-7:30
7:00-7:15
p.m.
p.m.
0130 -0230
0200 -0215
Tokyo, Japan
Tokyo, Japan
15.195, 15.42, 17.725, 17.825
15.105
MICROPROCESSOR 7:00-8:00 p.m. 0200 -0300 Peking, China 11.455, 11.965, 12.055, 15.06
FROM NATIONAL SEMICONDUCTOR, "THE 7:00-8:50 p.m. 0200 -0350 Taipei, Taiwan 11.86, 15.125, 17.72
SECRET MICROCOMPUTER CO ": THIS 40
PIN DIP FEATURES TRI -SHARE AND A 7:30-8:00 p.m. 02300300 Stockholm, Sweden 9.695, 11.705
POWERFUL INSTRUCTION SET. WE ARE 8:00-8:15 p.m. 0300 -0315 Tokyo, Japan 15.105
PROUD TO OFFER THIS EXCITING IC TO 8:00-8:30 p.m. 0300 -0330 Seoul, Korea 15.355
THE COMPUTER ENTHUSIAST STARTING 8:00-8:45 p.m. 0300.0345 Madrid, Spain 6.065, 11.925
SEPTEMBER 1st.
8:00-9:00 p.m. 0300.0400 Peking, China 7.12, 9.78 (via Tirana),

...and 16 bIT basic kit 11.445, 12.055, 15.06,

15.385, 17.735, 17.855
* MicrocomPuter *
IT SEEMED LOGICAL TO WRAP A
! 8:30-9:30 p.m.
8:30 p.m.-12 mdt.
0330-0430
0330-0700
London, England
Moscow, U.S.S.R.
9.58 (via Ascension)
11.72, 12.05, 15.18
COMPUTER KIT AROUND OUR PACE 9:00-9:15 p.m. 0400-0415 Tokyo, Japan 15.105
IC, AND HERE IT IS, WE'VE PUT 9:00-9:30 p.m. 0400-0430 Sofia, Bulgaria 9.70
A LOT OF THOUGHT INTO THIS ONE
AND WE THINK YOU'LL LIKE IT; Oslo, Norway 9.645, 11.87 (Sun.)
OUR ONLY PROBLEM IS WE DON'T
HAVE A NAME FOR THE BEAST YET. 4 9:00 -9:15 p.m.
(Tue., Fri.)
0400 -0415 Budapest, Hungary 6.00, 7.22, 9.833, 11.91

SEND US YOUR IDEA WE USE tS --IF 9:00 -10:00 p.m. 0400 -0500 Montreal, Canada 6.135, 9.655
IT, YOU'LL GET ONE OF OUR KITS.
AVAILABLE SEPT, 1ST; WRITE FOR 9:30 -10:00 p.m. 0430 -0500 Lisbon, Portugal 6.025, 11.935

e e.ec e e.ec e.ec

DETAILS AND PRICING.
10:00-10:15 p.m. 0500-0515
Berne, Switzerland
Tokyo, Japan
9.725, 11.715
15.105
-AND 8 BITS, T00 8008 - $27,95! ;

Jerusalem, Israel 12.025

MPMM.MOMM.OD4MMM.OMMMMMOM.MM
10:00-11:00 p.m. 0500-0600 Montreal, Canada 6.135, 9.655
10:00-11:20 p.m. 0500-0620 Hilversum, Holland 6.165, 9.715 (via Bonaire)

®DC3400 GODBOUT ELECTRONICS

10:30-10:50 p.m.
11:00-11:15 p.m.
0530-0550
0600-0615
Cologne, Ger. Fed. Rep.
Tokyo, Japan
6.075, 6.185. 9.545
9.505
BILL 11:00-11:30 p.m. 0600-0630 Oslo, Norway 9.645, 11.87 (Sun.)
BOX 2355. OAKLAND AIRPORT CA 94614
11:00 p.m.-12 mdt. 0600-0700 Buenos Aires, Argentina 9.69 (Mon. -Fri.)
11:30 p.m.-1:00 a.m. 0630-0800 Havana, Cuba 9.525
THIS IS ONLY THE TIP OF THE
AD
ICEBERG; OUR FLYER TELLS ALL 12 mdt.-12:15 a.m. 0700-0715 Tokyo, Japan 9.505
ABOUT OUR TTL (7400 & 8200 SER- 1:00-1:15 a.m. 0800-0815 Tokyo, Japan 9.505
IES), CMOS, MOS, LINEARS, COM- 2:00-2:15 a.m. 0900-0915 Tokyo, Japan 9.505
PONENTS, READOUTS, POWER SUP-
PLIES, MUSICIAN'S KITS,& MORE. 3:00-3:30 a.m. 1000-1030 Tokyo, Japan 9.505
SEND FOR IT BE SURPRISED!
*Reception quality, East Coast location: G -good, F -fair, P -poor
TERMS: Cal * tax. Bankamericard"/Master- * *Not intended for North America, but receivable satisfactorily
charge' call (415)357 -7007 24 hr. No COD.
CIRCLE NO. 24 ON FREE INFORMATION CARD Frequencies are accurate as of press time, but subject to change especially for Sweden, U.S.S.R and Lehanon.

e2 POPULAR ELECTRONICS

www.americanradiohistory.com
 TO EASTERN NORTH AMERICA

TIME -EDT TIME -GMT STATION QUAL" FREQUENCIES, MHz

7:00-8:15 a.m. 1100 -1215 London, England G 5.990 (via Sackville), 15.07
7:00-7:30 a.m. 1100-1130 Tirana, Albania F 9.48, 11.985
7:00-9:00 a.m. 1100.1300 . *VOA, G 6.185, 9.565
Washington, U.S.A.
7:15-8:15 a.m. 1115-1215 Montreal, Canada G 5.97
7:15-8:45 a.m. 1115 -1245 Melbourne, Australia G 9.58
8:00-8:55 a.m. 1200 -1255 Peking, China F 11.685
8:15-9:00 a.m. 1215 -1300 London, England G 15.07 DUAL IN-LINE IC'S
8:30-9:00 a.m. 1230 -1300 Stockholm, Sweden G 17.71 Made in U S. These IC's are
9:00-10:30 a.m. 1300-1430 London, England G 15.07, 17.79 guaranteed against detects.
wt. V. Ib.
Y9C With diagram. Stipe.
9:15-9:45 a.m. 1315-1345 Berne, Switzerland 15.14 LOW AS Type 7447 BCD to 7 -Seg-
G
With
10:00-10:30 a.m. 1400 -1430 Stockholm, Sweden G 17.71 2 -Input ment Decoder /Driver.
Type 7400 Ouad High common anode displays.59c
Oslo, Norway F 17.80 (Sun. only) Pos. NAND Gate. in-
Sale
speed diode-clamped Type 7473gDua19J Ma
Helsinki, Finland G 15.185 puts 29c ter I Slave Flip-Flop.
TR -431. Reg 69c Sale TR -43674
10:30-11:00 a.m. 1430.1500 Lobdon, England G 15.07, 17.79, 17.84 (via Ascension) Type 7402 Ouad 2 -Input Type e Duel SD--Type
Poe NOR Gate. Low -noise
Edge Triggered Flip
-Flop.
11:00-11:15 a.m. 1500-1515 London, England G 15.07, 15.26, 17.79, 17.84 Propabon delay 12
ris.
e
7475 4- BIt $e Latch.
(via Ascention) Type
pe 7404 Rex Inverter.
Type dis- Temp stores binary coded
11:15 a.m. -12:15 p.m. 1515 -1615 London, England G 15.07, 17.79, 17.84 (via Ascension) Low noise. low power
sipation 29c TR -e37 1 B9 ale 79c
12 noon-12:30 p.m. 1600 -1630 Oslo, Norway F 15.17, 17.80 (Sun. only) TR -433. Reg. 79c Sale t Type 90 Decode
Type Tripla
4:00-4:55 p.m. out- tewith sym-
2000-2055 Jerusalem, Israel G 7.395, 9.815, 12.025 .
decimal counter
impedance,LOdiode- metrical divide.
5:15 -6:45 p.m. 2115 -2245 London, England G 9.58 (via Ascension), 11.78, 15.26 clamp Inputs TR -439. Reg 1 89 Sale 79c
Reg Sels 29c
5:30 -6:50 p.m. 2130 -2250 Hilversum, Holland G 9.715, 11.73 (Sun.: Dutch)
6:30 -7:00 pm. 2230.2300 Vilnius, U.S.S.R. F 7.32, 7.355 Rechargeable BIS I LB.
Battery
6:30 -7:20 p.m. 2230 -2320 Johannesburg, S. Africa G 5.985, 9.525, 9.695, 11.90 With Charger Resistor
6:45 -11:30 p.m. 2245.0330 London, England
-
G 5.975, 7.325, 9.58 (via Ascension) 6 VDC alkaline Kit
rated @ 5 amp hr Over 400 pieces of
6:55 -7:15 p.m. 2255 -2315 Brussels, Belgium G 9.73 81 Max. c enr 1 25 z, 1 watt sizes
7:00 -7:30 p.m. 2300 -2330 Stockholm, Sweden F 6.035, 9.605, 11.705 mp Eveready All color coded

7:00 -8:30 p.m. 2300 -0030 Moscow, U.S.S.R. G 7.15, 7.205, 7.355, 7.39, 9.685
Reg. #565 4 lbs
9.98 BA -307. Sale 4.99 990 215
RS -239.
lbs
99c

7:45 -8:45 p.m. 2345 -0045 Tokyo, Japan F 15.27, 15.30 500 -ft. Y PNP
8:00-8:30 p.m. 0000 -0030 Tirana, Albania 7.065, 9.78 Nook -,Up Transistors
Oslo, Norway
G

F 6.18, 9.645 (Sun.)

For almost any
Wire gl,
Big 10 pc Ito For
enera l0 8
gain 8 at
i-

8:00 -9:00 p.m. 0000 -0100 Peking, China F 11.945, 15.06, 15.52, 17.673 lype of printed co- Germanium types
cultt or wiring pro- Untested 'e lb
Sofia, Bulgaria F 9.70 911
2.98 lecl 2 lbs 390
Reg. 99e
TR -445. Soie 39c
8:00 -10.00 p.m. 0000 -0200 * *VOA, G 6.13, 9.65, 11.710, 11.83, 15.205 WW-579. Sale 1.69 TR -444. NPN. 39c

8:30-9:00
Washington, U.S.A.
a
T,1 ' 4z 3-6Motors
VDC _ Three
60 -Min.
8:30-9:00
p.m.
p.m.
0030.0100
0030 -0100
Kiev, U.S.S.R.
Vilnius, U.S.S.R.
G
F
7.15, 7.205, 9.685 (Mon, /Thu, /Sat.)
7.32, 7.355 (Fri. /Sat.) T Kit. 5 Small
MO -333. Sale 55c
i, Pb t_l Cassettes
Pkg 3 quality
8:30-9:00 p.m. 0030 -0100 HCJB, Quito, Ecuador G 5.97, 9.56 LOW AS kit 14. Med. 1 lb cassette record-
MO. 334 Sale 790 ing tapes 60- Min
8:40-9:00 p.m. 0040 -0100 Brussels, Belgium G 6.08 99c
9:00-9:15 p.m. 0100 -0115 Vatican City 59c Kit: 4 Aeetd.2 lbs. each tz lb
Reg. 1.49 TA -879. Sale 990

12 -Digit IC ;8T Blank Tape

G 5.995, 6.165, 9.605 MO.335. Sale 99c

9:00-9:20 p.m. 0100 -0120 Rome, Italy G 9.575, 11.81

9:00-9:45 p.m.

9:00-10:00 p.m.
0100 -0145

0100.0200
Berlin, Ger., Dem. Rep.
Madrid, Spain
Peking, China
P

G
G
9.73
6.065, 11.925
7.12, 9.78 (via Tirana), 11.945,
11.965, 15.06, 15.52
4 Calculator Chip
a
59
a
`\
40-pm DIP single
CAL -Tech *CT
5001 7 - sag d,-
c deddisplayoul-
put, Overflow lock
Reg. out Specs Ince
-
09e
Famous manutac-
er
low
high qual-

.,ipos I, lb
TA -954.
40-Min.
TA -855.
priced

89c

Prague, Czeckoslovakia G 5.93, 7.345, 9.54, 11.99 5.98 5M -330. Sale 1.59 Reg. 1.19 00 -Min. 99c
9:00 p.m.-3 a.m. 0100 -0700 HCJB, Quito, Ecuador G 5.97, 9.56, 11.915
0Pc. Amp 1
Silicon
(includes some Eskimo) Diode Kit Rectifiers
la 4 Lv 1 Amp Epoxy Type
9:00-10.00 p.m. 0100-0200 Montreal, Canada G 6.085 Polarity is un- Pko.i5. 4 oz.
marked but easily Reg Sale
9:00.10:30 p.m. 0100 -0230 Moscow, U.S.S.R. G 7.15, 7.205, 7.355, 9.685 identified 13I-028 50 PIV IN4001 B9c 39c
ohm meter 200 DI -029 100 PIV IN4002 99c 39c
9:30-9:50 p.m. 0130 -0150 Cologne, Ger. Fed. Rep. G 6.01, 6.04, 6.10 (via Malta), PIV rated. ih lb. 01-030 200 PIV 104003 1.19 39c
9.565, 9.69, 9.745, 11.865 REG. 1.69 Dl -051. Sale B9c DI -031 400 PIV 154004 39 39c 1

(via Malta) Switching

9:30-9.55 p.m. 0130 -0155 Tirana, Albania G 6.20, 7.30 Diodes LED'S 2V
Vienna, Austria P 6.155, 9.77
Pkg 10 154148
for low current ap-
10mÁ
plications 10 mA- Gallium phos-
Bucharest, Rumania P 5.99, 9.57, 11.94 59C 75 PIV '., lb
cphide Large red
high quality LED.
9:45-10:15 p.m. 0145 -0215 Berne, Switzerland G 5.965, 6.135, 9.725, 11.715 Reg. 1.29 xM -382. Sale 59c
WI '.i lb Pkg,5
10:00-10:30 p.m. 0200-0230 Budapest, Hungary F 6.00, 7.22, 9.833, 11.91 (Ex. Sun.) Reg. 1.19 PL-233. Sale 59c
Oslo, Norway F 6.18, 9.645 (Sun.) SCR
10:130-11:00 p.m.
10:00-11.20 p.m.
0200-0300 Peking, China
Hilversum, Holland
F 11.965, 15.06
6.165 (via Bonaire)
9 Assort-
ment
0200-0320 G
Hobby Pak of
10:00-11.30 p.m. 0200 -0330 Cairo, Egypt 9.475

ols°'
G
asst. values 8 case
6.095, 6.135, 7.27, 9.675,
10:00 p.m.-12 mdt. 0200 -0400 Warsaw, Poland P

11.815 (mixed Polish /English) at 990types Pkg.

Untested. WI lb
Reg. 2.69 TR -446. Sale 99c
25
1

rÑOU5RNp5 Of
10:30.11:00 p.m. 0230 -0300 Beirut, Lebanon P 9.675
ORDER TODAY! Send to
11:00.11:30 p.m. 0300 -0330 Budapest, Hungary F 6.00, 7.22, 9.833, 11.91 Olson Electronics, 260 S.
11:00 p.m. -12 mdt. 0300 -0400 Buenos Aires, Argentina G 9.69 (Mon. -Fri.) Forge St., Akron, Ohio
44327. Allow for postage.
Peking, China G 7.12, 9.78 (via Tirana) C.O.D. 20% Deposit. Ohio
Prague, Czechoslovakia G 5.93, 7.345, 9.54, 11.99 Residents Add 4 %Sales Tax.,
11:30 p.m. -12 mdt. 0330 -0400 Tirana, Albania 6.20, 7.30
Kiev, U.S.S.R.
G

G 7.205, 7.39, 9.685

Olson. electronics Dept IB
260 S. Forge St., Akron, Ohio 44327
(Mon. /Thu. /Sat.)
11:30 p.m.-12:30 a.m. 0330-0430 London, England G 5.975, 9.58 (via Ascension) NAME
11:30 p.m.-2:00 a.m. 0330-0600 Havana, Cuba G 11.76
ADDRESS APT
12 mdt.-12:30 a.m. 0400-0430 Bucharest, Rumania P 5.99, 6.19, 9.57, 11.94
12 mdt.-2:00 a.m. 0400-0600 Moscow, U.S.S.R. G 7.15, 7.205, 7.355, 7.39 CITY STATE ZIP
1:00-1:15 a.m. 0500-0515 Jerusalem, Israel G 5.90, 7.395, 9.009, 9.815
CIRCLE MO. 38 ON FREE INFORMATION CARO
SEPTEMBER 1975 83

www.americanradiohistory.com
 Solid State
By Lou Garner
NEW IC'S FOR DIGITAL WATCHES
WITH the entertainment equipment market well the legendary "Swiss watch movements," the WM devices
covered and the calculator market approaching sat- are complete electronic digital modules ready to slip into a
uration in many areas, several semiconductor manufac- basic watch case. All that is required for final watch as-
turers are concentrating their big guns on the digital elec- sembly is a suitable standard 13 ligne case (1.152 inches in
tronic watch market. The result? Improved quality. better diameter), pushbotton actuators aligned to contact the
distribution, much lower prices. and a plethora of designs module's integral switches, and a pair of small battery
to suit virtually every need and desire. cells.
As predicted in my January column, digital electronic Currently, three standard models are offered by the
watch prices have taken a nose dive. Today, you can buy manufacturer-the WM 01, WM 02 and WM 03. All three are
any of a number of calendar digital watches for less than pretested and precalibrated for an accuracy of better than
$100.00, and I've seen standard (time only) watches offered 5 seconds per month. As illustrated in Fig. 1. the WM
for less than sixty dollars retail. If you shop at discount modules include a CMOS timer chip, a 2.5 -mm four -digit
houses, you may be able to pick up a digital electronic LED display. segment and digit LED driver chips, a
watch for less than $50.00, despite inflation. 32.768 -kHz quartz crystal. an oscillator. a timing adjust-
More and more major semiconductor manufacturers are ment capacitor. battery contacts. and built -in spring
offering digital -watch ICs as stock, rather than custom, switch elements with special debounce circuitry to insure
products. In last June's column. you may recall, discussed I positive contact actuation. Designed for rugged service,
the DF111 CMOS LSI watch chip introduced by Siliconix. the oscillator crystal is potted in a compound that absorbs
Inc. (2201 Laurelwood Road, Santa Clara, CA 95054). Suit- shock, while another specially developed compound coats
able for operation on dc sources of 2.7 to 3.4 volts, the all the semiconductor components and protects them
DF111 requires only a 32.768 -kHz crystal, batteries, a LED from handling and environmental damage.
display with drivers, and three small switches, plus a case In operation, the circuits low power consumption per-
and hardware for watch assembly. mits more than twenty time checks per day for one year
The ne plus ultra of digital watch devices, however. is with a single pair of 1.5 -volt batteries. A special extra fea-
probably the WM series recently introduced by the Na- ture permits the user to turn off the module during ship-
tional Semiconductor Corporation (2900 Semiconductor ment or periods of storage and thus to obtain an indefinite
Drive. Santa Clara, CA 95051). The electronic equivalent of shelf life.
CASE
BACA THIS SWITCH ON
1--
-i,,Y
,Si
WM 02 AND WM 03
ONLY
11 1

H: -,---I DISPLAY SW
INKS MIN SRI

DISPLAY SET
DATE
SET SW
CMOS E DIGIT OAT E SW
TIMING SEGMENT
OSC )SEGMENT
DRIVER
CHIP lfS DISPLAY

EREDUNGY DIGIT 1
ADJUST DRIVER
A B

BATTERY CAVI EIES

POSITIVE
BATTERY 4096 Hz
CONTACT TEST POINT
MARKED BY
NOTCH

Fig. I. 1lnxir Elr..igll of

1
13.97mm Not limo I :U;e Sil ¡('O) (I oto,
IO IO o

10.5501 SYM new lior of 'catch nunlalr..:

I.-tl block ElingrEElll; 1111 rirvr
of rrElElulft; I(') (vol. l'iE-IE
LABEL
sAniEing hnllrr!/ rErritir.c.
NEGATIVE
BATTERY
1.397mm
CONTACT
10.055)
84 POPULAR ELECTRONICS

www.americanradiohistory.com
 The basic WM 01 module is designed to display the time
in hours, minutes and seconds upon pushbutton com-
mand. Models WM 02 and WM 03 are generally identical to
NEW FROM TECO
the WM 01 except for an additional capability of displaying
the date of the month on command. The WM 02 displays TRI Model 6355 Digital Multimeter $279
time in a 12 -hour format with an AM /PM indicator, while the
TRI Model 5163 250 MHz Frequency Counter $295
WM 03 displays time in a 24 -hour format.
Siliconix and National Semiconductor are not the only High resolution 10µV
major semiconductor manufacturing firms making waves on DCV /High accuracy

in the digital watch market, of course. Litronix, Inc. (19000

0.55% of rdg.
5 functions In one
DCV ACV. OHM, DCI,
-
Homestead Road, Cupertino, CA 95014) has recently an- ACI.
Fully automatic for
nounced a new CMOS circuit chip for LED watches that
displays hours, minutes, seconds, day and date. Desig-
Truly portable -
easiness of operations
Free
from power Cord.
Common input for all
nated type LMC -6130, the Litronix chip requires a measurements.
MODEL 6355 Safety design protects
32.768 -kHz quartz crystal, two capacitors, two resistors, from high voltage.

bipolar driver chips, a suitable LED display, and external 1 NEW!

spst switches. In practice, up to eight modes of operation $279
may be selected by switch actuation: display off, display
time, display date and day, advance hours, advance min- +250 MHz

utes, advance day, advance date, and zero seconds while 25mV sensitivity
8 rngits/LED
holding hours and minutes. Designed for operation on
NEW!
2.7- to -3.2-volt dc, the LMC -6130 requires only 15 NW, and MODEL 5163
$295
will function from 0° to 50° C.
Motorola Semiconductor Products, Inc. (Box 20912,
NOW AVAILABLE FROM TECO!
Phoenix, AZ 85036) is now offering a pair of low -power CALL OR WRITE FOR COMPLETE SPECIFICATIONS
liquid -crystal watch displays, types MLC500 and MLC501.
Differing slightly in overall size, both feature a 31/2- digit,
center-colon readout. Both offer a typical contrast ratio of TECO TOLL -FREE CALL
800 -527 -4642
25:1 at 3 volts bias, both feature turn -on and turn -off times P 0 Bo, 1050 e Garland. Texas 75040 (In Texas call collect 214 -348 -8800)
of 290 and 250 ms, respectively, and both are compatible
with standard CMOS watch IC's. CIRCLE NO 58 ON FREE INFORMATION CARD

Reader's Circuit. Combining magnetic reed switches

and semiconductor devices, the circuit illustrated in Fig. 2
is suitable for an electronic game or puzzle. Adapted from
a design submitted by reader Joel Grodstein (400 South

E
Fourth Ave., Highland Park, NJ 08904), the game can be
made simple enough for children to enjoy or so difficult
that even an adult would have trouble winning.
Referring to the schematic diagram, SCR1 serves as an
electronic switch supplying power to the LED used as a WIN
indicator through current limiting resistor R1. Power is
furnished by battery B1, controlled by switch Si. The ac-
tual game circuit consists of from 3 to 9 (or more, at the
builder's option) magnetic reed switches and SCR2. Game
1975 CATALOG
circuit power is supplied by C1, charged by B1 when
momentary contact switch S2 is depressed. Capacitor C1
OF
discharges through R2, providing a time limit on play. CIRCUIT
Optional rotary switches S3 and S4 are used to program DESIGN
the game, making it more difficult for the player. One or AND
more reed switches are included as PENALTY switches BREADBOARDING
which, if actuated accidentally, will discharge C1, thus EQUIPMENT
causing the player to lose. With the arrangement shown,
Send for your free copy of Circuit Design's
the PENALTY switches are SC1, SC2, and SC3. Resistors R3
new 1975 catalog. In it, you'll find lots of new
and R5 limit the gate currents of silicon controlled rec- ideas in solderless breadboarding aids and
tifiers SCR2 and SCR1, respectively, while R4 serves as instrumentation (in kit form or assembled),
SCR2's cathode load. as well as a host of hard to find compo-
The circuit's operation can be followed most easily by nents. If you are involved in any asoect of
considering the moves that a player would make in win- electronics, you can't do without it.
ning the game. First, of course, S1 would be closed. Next, For your free copy, write to:
S2 would be depressed (charging C1) and released. The
player would then touch his playing piece (small perma- CIRCUIT DESIGN, INC.
nent magnet) to reed switch SB1, closing this switch Div. of E &L Instruments
.0. Box 24 Shelton, Connecticut 06484
momentarily, supplying a gate current to SCR2, and caus-
ing the SCR to switch to a conducting state. He would then
CIRCLE NO 12 ON FREE INFORMATION CARO

SEPTEMBER 1975 87

www.americanradiohistory.com
touch his playing piece to reed switch In practice, of course, the game can may be necessary. Normally, this re-
SA1, closing this switch, supplying a be quite difficult. The programming sistor should have as large a value as
gate current to SCR1, and causing the switches (S3 and S4) are hidden. The is practicable while maintaining
SCR to fire and supply current to the player is confronted with an array of SÇR2's holding current.
WIN light (LED1) through R1. However, reed switches arranged in a row, rec- If you wish to simplify the game for
he must touch the switches in proper tangular matrix, or random pattern, children, omit the penalty switches
order, since they remain closed only depending on the builder's choice of (SC/ to SC3), increase the size of Cl
as long as the magnet is held against layout. He doesn't know which two and /or R2 to lengthen the playing
(or near) them, and within the time switches will win. If he accidentally ac- time, omit the programming switches,
limit established by C1 -R2's time con- tuates one of the penalty switches and provide only a single reed switch
stant. In addition, when SCR2 fires, R4 (SC/ to SC3), he'll lose. And, once he in each playing position. On the other
is an additional load across Cl in depresses S2, he has a limited amount hand, if you wish to make the game
parallel with R2, thus causing a sharp of time to complete his moves. And more difficult, add additional penalty
reduction in the available playing only two switches, actuated in proper and play switches (changing the pro-
time. order, will register a win. gramming switches as needed to 4, 5,
Ideally, the game should be assem- 6 or more positions), and replace R2
bled in a wooden, plastic or metal with a 10,000-ohm resistor in series
BETTER case, with only the ON -OFF, PUSH -
TO -PLAY and reed switches avail-
with a 50,000 -ohm potentiometer to
provide a variable time delay.
able to the player and the pro- Once the project is completed and
THAN A gramming switches hidden. The sili-
con controlled rectifiers, SCR1 and
tested, it can be used in a variety of
ways. You can use it as a simple puzzle
THIRD HAND! SCR2, are low- voltage types similar to
HEP 320. The LED may be any stan-
to challenge your friends, for example,
or in competititve play, where different
dard type. Resistors R1 to R5 are players take turns resetting the pro-
1/2 -watt types. The capacitor, Cl, is a gramming switches for their oppo-
10 -to -15 -volt electrolytic. A 9-volt bat- nents, with the player having the
tery is used for B1. The power switch is greatest number of "wins" in a given
a spst toggle, rotary or slide type, number of attempts declared the win-
while S2 is a momentary contact spdt ner.
pushbutton or lever type. Pro-
gramming switches S3 and S4 are ro- The Lit Bit. Recent publications by
tary types, with the "play" switches all semiconductor manufacturers which
small magnetic reed types similar to you may wish to add to your library:
Calectro type E2 -102.
Neither layout nor lead dress is criti- Power Transistor Users Guide
cal and the circuit may be assembled -Published by General Electric,
on a pc board, on perf board, or using this is a 120 -page, 81/2 x 11 manual
point -to -point wiring, as preferred. filled with practical data on power
The reed switches may be left exposed transistor circuit applications, han-
on the playing surface or, if desired, dling and mounting. The book covers
PANAVISE TILTS, TURNS, AND hidden behind a thin panel on which GE's broad line of power transistors,
ROTATES TO ANY POSITION. locations are marked by dots or cir- including complementary pairs, Dar -
IT HOLDS YOUR P.C. BOARD cles. Depending on the SCR's used, lingtons, and high -voltage types, as
EXACTLY WHERE YOU WANT IT. some experimentation with R4's value well as both metal and plastic encap-
Quite possibly the finest new tool
you will buy this year. PanaVise is SAI
built to exacting professional
standards. We guarantee it!
Illustrated is P.C. Board Holder
#315 in the #300 Base. This com-
bination has exclusive multiple
positioning ability. Boards are
gently but firmly locked in place
with one arm spring loaded to
facilitate quick board changes.
Three other bases and a wide va-
riety of heads are available. All
interchange! Buy a basic unit, then
add on to create your system.
FREE Write for the latest PanaVise
catalog, prices, and dealer listing.
Available through your dealer.

A-N- AVISE Dept. 15E

A Division of Colbert Industries
Fig. 2. Schematic u/' versatile gaine
10107 Adelfa Ave., South Gate, CA 90280
CIRCLE NO. 41 ON FREE INFORMATION CARD
circuit suggested by render.
88 POPULAR ELECTRONICS

www.americanradiohistory.com
sulated devices. Two items we found terested in a new high- current
of particular value were a 16 -page in- decoder /driver recently introduced by
terchangeability guide referencing GE NEC Microsystems (1150 N. W. 70th
devices to standard industry types and St., Fort Lauderdale, FL 33309). Iden-
a component chart which illustrates tified as the Model 1001, the new de-
basic devices, symbols, construction, vice is a thick -film hybrid microcircuit
and characteristic curves. The book designed to operate incandescent
carries a nominal price of $1.50, but 7- segment readouts. Socket inter-
may be available without charge to changeable with the popular SN7447,
quantity device users. It is stocked by the Model 1001 utilizes individual out-
GE Electronic Components Sales Of- put transistor chips which are rated at
fices and authorized GE Electronic maximums of 40 volts and 100 mA,
Components distributors. each output, in continuous operation.
Both plastic -encapsulated and her-
Small -Signal Multiple Transistor metically sealed metal versions are of-
Selection Guide & Cross - fered by the manufacturer.
Reference, Publication SG31 -A An unusual solid -state vane sensor
24 -page booklet covering Motorola's that should spark the imaginations of LOOKING FOR INNOVATION?
broad line of quad, dual and Darling- more advanced experimenters has LOOK TO PAIA KITS.
ton transistors. Complete specifica- been announced by Micro Switch (Di- Some recent examples ....
tion tables are included together with vision of Honeywell, 11 W. Spring St., The GNOME, The only Electronic Music
Micro -Synthesizer available in a hand held,
device outlines and a competitive Freeport, IL 61032). Capable of func- battery powered package.
cross -reference index. Notes are pro- tioning at speeds up to 100,000 times $48.95 shipping wt. 4 lbs.
vided on power ratings and general per second, the device, designated the The PYGMY, battery powered practice/
headphone /stage amp. 8 watts peak power
applications are suggested for various AV, can be used as a tachometer sen- driving super- efficient 5" accoustic suspen-
product categories. Contact your sor, a shaft -position encoding sensor, sion speaker.
local Motorola distributor for copies. a limit switch and a cam -operated $39.95 shipping wt. 6 lbs.
programming switch. Based on the NEW 24 HOUR DEMO-LINE for a one -
minute recorded demo of PAIA Synthe-
Opto- Couplers at Work-A 20- Hall Effect and with no mechanical sizers (405) 843 -7396. Catalog requests or
page booklet chock full of practical contacts, the AV "no- touch" sensor is charge orders also accepted.
application circuits for Motorola's line actuated by the passage of a ferrous FREE CATALOG
of Opto- Couplers. Each circuit in- vane through a gap between a magnet PAIA Electronics, Dept. 9P, 1020 West
cludes a brief description and all parts and a Hall sensor. The vane prevents Wilshire Blvd., Oklahoma City, OK 73116
values are noted directly on the the magnetic flux from reaching an IC CIRCLE NO. 40 ON FREE INFORMATION CARO

schematics. Among the projects de- chip, developing a digital output

scribed are a digitally programmed dc signal. When the space between the
voltage regulator, a high- voltage,
complementary output switching am-
ferrous blades of the vane appears in
the switch gap, the output returns to
SAVE ON
plifier, and a variety of solid -state relay zero. Both linear and rotary vanes may
circuits. The booklet also includes a be used with the device. With a 20-mA
Brand Name Audio
cross-reference guide to the products output, the AV interfaces directly with Components
of other manufacturers. (Motorola
Semiconductor Products, Inc., Box
most electronic circuitry, eliminating
the need for additional amplification Write Today for Our
owl"'
20912, Phoenix, AZ 85036). in most applications. Internal regula- FREE Audio Catalog
tion permits the device to be used on DIXIE is one of the oldest and largest audio compo-
Semiconductor Data Book dc power sources of 6 to 16 volts. nent mail order houses in the country. Our prices on
brand name components are actually LOWER than
1975 -A massive 418-page, 81/2 X 11 If you like to build amplifiers that "Discounters'. See our new catalog or call us for a
price quote. Everything shipped factory- sealed with
handbook covering the Unitrode line can rattle teeth, shake walls, and shat- full manufacturer's wa runty.

of semiconductor devices. Full ter sanity, you'll want to investigate a

specification data sheets are provided new high -power transistor recently in-
mauercna,ge
_-.
Mastaohera/
......
Ber,kAm .Ica
ajit7'7
1411_
MOSS

1
for such devices as power hybrid cir- troduced by RCA's Solid State Divi- honored aorde"
d
1111

5
',E183111'-
cuits, rectifiers, rectifier assemblies, sion. An npn silicon hometaxial-base l' L------
1i14i1. hdII1EN11 SRURE
''. a®.
power zeners, power switching tran- device offered in a TO -3 package, the PIONEER MARAM72 1-',
sistors, power Darlingtons, SCR's, new transistor, type RCS258, has a awl
photo- sensitive devices, PUT's, and
pin diodes. Available without charge
power dissipation rating of 250 watts!
Its other specifications include a con-
?.s SONY :,_Oû
`IUUAI OYMACO

on letterhead request, the volume also tinuous collector current rating of 20

DIXIE HI. FIDELITY
includes an index of available Applica- A, a peak collector current of 30 A, and 5600 Secono St., N. E., Washington, D. C. 20011
tion Notes and a detailed discussion of a collector-to- emitter voltage rating of Phone: 1-202á354900

thermal design considerations. (Uni - 80 volts. In addition to applications as Preme rush me your FREE Audio Catalog and
complete information. I understand mere is no
trode Corp., 580 Pleasant St., Water- an audio amplifier, the RCS -258 can obligation.

town, MA 02172) be used in power- switching circuits, Name

driver and output stages for series Address
Device/Product News. Experi- and shunt regulators, dc-to-dc con- City

menters and hobbyists working verters, inverters, and solenoid /relay

State Zip_ PE-9
with digital displays should be in- drivers.
SEPTEMBER 1975 89

www.americanradiohistory.com
 ALLISON VIDEO
`OPTO- ELECTRIC' PING PONG
The BEST...the ULTIMATE
of ALL Ignition Systems!
(We challenge ANYONE
to dispute this Fact(

Tips &Techniques
Never wears out or needs any Maintenance! 60- Second Interval Timer
In some situations, such as timing
Po)aroidTM scope photos, it is useful to
gives you Maximum Power have a 60- second timer. In the circuit
with continuous PEAK PERFORMANCE
+SV
...while reducing Maintenance
and Operating Costs!
*The Allison OPTO- ELECTRIC System eliminates the Points
and Condenser. replacing them with an OPTO- ELECTRONIC
TRIGGER, using a Light- Emitting Diode and Photo transistor
The System operates on a beam of Light. As there are NO ATTACHES TO TV ANTENNA
moving parts in rubbing contact. 'Friction -wear is completely H7K
eliminated Timing adjustments are PERMANENT.
Gives 40 -Times more Timing accuracy than ANY system
PLANS, PC CARD, COMPLETE
using "Mechanical Breaker- Points! UNLIMITED RPM! KIT AVAIL.
"Electronically -Controlled" DWELL automatically supplies
HIGHEST Performance at both Low and High speeds Spark
strength does not fall off at high RPM POSITIVE SPARK ONLY 14 IC'S (7400 FAMILY)
helps eliminate "Misfire for faster acceleration and improved
Engine Performance Sparkptugs LAST 3 to 10 -Times LONGER.
HOTEST ELECTRONIC GAME IN TOWN
Easier Starting under any condition! Smoother running...
!o - NOW CUSTOMIZE YOUR OWN HOME
(NO TIMING FLUCTUATION as with Magnetic Impulse Units(
All SOLID -STATE Components. UNAFFECTED By Temperature.
TV - SEND 50v FOR INFO PACK - RE-
Moisture, or Vibration! Only Highest grade materials used FUNDED WITH PURCHASE
Guarantees you Solid, Dependable Performance! 74'12 1 1w

PERFECT TIMING INCREASES Engine Efficiency and Gas VIDEO GAMES

Mileage SAVES Precious Fuel! Allison gives you MAXIMUM 7 3
Engine Efficiency 100% of the Time and that the name of
1
20650 RUNNYMEDE, CANOGA CA 91306
the game for the BEST MILEAGE AND ECONOMY

*
in GAS CIRCLE NO. 61 ON FREE INFORMATION CARD

Perfect Timing and Dwell never change.

Pays for itself! Eliminates ignition Tune -Ups forever!
SOo.1¿
Loi
"INFINITE LIFE" Once installed Never needs replacing!
5íAR-r
* PROVEN RELIABILITY!
Each Unit Tested to 15,000 RPM.
Road and Race Proven.
(Opto- Electric Systems won at LED
INDY Two years in a row!)

You CAN install the ALLISON System in ALL

THE SHOPPING CENTER
the U.S made & Foreign Cars! (4. 6. or 8- Cylinder).
shown, dep essing the pushbutton will FOR ELECTRONICS
cause the LED to go off (it is normally on), HOBBYISTS ... EXPERIMENTERS ...
"EASIEST -TO- INSTALL" UNIT ON THE MARKET.
Not necessary to dismantle Distributor as with other systems) and then light again after 60 seconds. Ad- SERVICE TECHNICIANS ... ENGINEERS.

* If you want the BEST.and SAVE! This is IT!

just the time interval to exactly one minute
by varying the 100-k pot. YOUR SATISFACTION
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Send Check or M 0 Postage B Insurance find that the Teflon nozzle clogs with hard -to -find Parts whether you

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solder occasionally. To prevent this, place
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FET -VOM -
want a 15x- capacitor. or a $50
you can get it at EDI!

You may use your MASTER CHARGE or BANKAMERICARD.

nozzle before use. While the oil might Transistors, ICs, Modules,
Send us (1) Your Number. (2) Interbank No (3) Exp. Date. Speakers, Stereo, Hi -Fi,
smoke slightly from contact with hot sol-
* Before buying any other Type ignition system der, this is harmless and eliminates fre-
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Opto- Electric "TRIGGER UNIT "...Only '34.95 Plastic "Clips" Identify Cables
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. NAME
Address
City State Zip
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 ferrite loop antenna coil for the AM
band (Lafayette 34 F 87485). The
capacitor should be a 365 -pF variable
unit. The Lafayette 99 F 62176 is ideal

¿1YÖW Hobby Scene for this purpose since it has a cali-

son

brated dial. Install L and C in a metal

utility box, which is bonded to a good
earth ground. Be sure to use coaxial
cable from the antenna to the trap, and
from the trap to the receiver, and tie all
chassis together by means of the coax
CAPACITANCE MULTIPLIER BROADCAST INTERFERENCE FILTER
braid. Adjust C for a null at the broad-
Q. I'veheard that it's possible to use Q. I have a small shortwave receiver cast station's frequency and most of
a transistor to "amplify" the capa- and am experiencing interference its signal will be shunted to ground.
citance of a fixed capacitor. What from a new AM radio station on 1170 When listening on the AM broadcast
does the circuit look like, and how kHz. I pick up the AM station at many band, (when filtering is not desired)
much capacitance can be gotten points on the shortwave bands. Is open the switch.
from it?- Philip Alfonso, Highlands, NJ there any way I can stop this
REGULATED CURRENT SOURCE
interference? -Doug Wirth, Somer-
ville, N.J. Q. I need a current source with a regu-
lated output covering 50 to 200 mA. Do
A. A capacitance multiplier (Fig. A) A. The interference you are experienc- you have a circuit?
can be used. It smooths a pulsating dc ing is due to receiver overloading. Be-
voltage into a ripple -free one. The ef-
-R. Crumb, Gary, Ind.
cause you are so close to the broad-
fective filter capacitance, CF, is eugal cast station, its field strength at your A. If you apply 50 V to the input of the
to the product of Cr, the base filter home is very high. The shortwave re- circuit shown (Fig. C) 50 to 200 mA of
capacitor, and ß, the current gain of ceiver just can't cope with the strong regulated current can be obtained at
the transistor. It is possible to simulate signal levels and is generating false the output. Adjust the potentiometer
capacitance values up to one farad or signals on the shortwave bands. A for the desired value. Use a good heat
more by using medium -size electroly- simple signal trap should be installed sink on the pass transistor to avoid
tics and high -beta transistors. as shown (Fig. B). The coil can be a thermal instability.

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 Now the most
enjoyable,
do- it- yourself
project of your
life- a
4
Schober Electronic Organ!
You'll never reap greater reward, more fun
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Five superb models, with kit prices from Substitution Handbook has been updated
5575 to around $2,300, each an authentic by the Howard Sams Engineering Staff to ON FAMOUS BRAND
musical Instrument actually superior to most include the latest type numbers. Section 1 NATIONALLY
you see in stores.
Join the thousands of Schober Organ contains substitutions for American and ADVERTISED
builder- owners who live in every state of the foreign transistors, arranged in numerical
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CIRCLE NO. 1 ON FREE INFORMATION CARO

RCA COLOR TV SERVICE HANDBOOK

The fifth volume of RCA's Color TV Service Major Advance. . .

LISTEN!
We're one of
Handbook provides service data for 1973
and 1974 models of 16 manufacturers, in-
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soope
o Rf
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of Stereo checks, RCA tube and SK semiconductor
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MODULE BASIC PAP TS KIT amateur radio operators) is described. A
FEATURING AN
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1 CMOS INTEGRATED G51

appendix.
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FEW CAPACITORS AND RESIS-
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Instruments,
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Published by Rand McNally and Co., 10 E.
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BOX 1005
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53rd St., New York, NY 10022. 98 pages
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ELECTRONIC CIRCUIT BEHAVIOR

No. 7566 No. 7577 by Daniel Metzger "Build -it- Yourself" and save
Micro Soldering Tip Chisel Tip An overview of electronics, including a
up to 50% with our famous
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No. 7535 No. 7574 and theorems, introduces this work. Using electronic kits.
Regular Tip Concave Tip simple algebra and right -triangle trig-
onometry, the author describes how ac- For latest EICO Catalog on Test
tual electronic components work in a cir- Instruments, Automotive and Hobby
No. 7546 No. 7569
Heavy Duty Tip ), ( "V Tip cuit, rather than going into deep theoreti-
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No. 7596 No. 7573 of nearest EICO Distributor, check reader
Knife Tip Tinning Tip lar), switching and amplifier circuits,
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clude schematic symbols, popular pack- Brooklyn, N.Y. 11207
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ages, charts, tables, formula derivations, Leadership in creative electronics
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 ABOUT YOUR- -
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1 the world's most modern, efficient
STD.
NY 10016. For those who can help readers. please re- computer systems, and if you're like
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items regarding equipment not available from normal
have any reason to complain about
sources are published.)
your subscription service.
We have found that when com-
12 REASONS YOUR CAR plaints do arise, the majority of them
occur because people have written
NEEDS TIGER CDI York 4 -Band Portable Radio. Model G34. Schematic. L. their names or addresses differently
Palliser, c/o Pecan Manor, Central State Hospital. Mil- at different times. For example, if
Instant starting in any weather - Eliminates ledgeville, GA 31062. your subscription were listed under
tune -ups - increases gas mileage - Increases "William Jones, Cedar Lane, Mid-
horsepower 15% - Improves acceleration Precision Apparatus Tube & Battery Tester, Series 612. dletown, Arizona," and you were to
and performance - Spark plugs last up to renew it as "Bill Jones, Cedar Lane,
Source or copies of tube update rollers. Albert Stock. RD
70,000 miles - Reduces engine maintenance
expense - Amplifies spark plug voltage
1, Bushkill. PA 18324. Middletown, Arizona," our computer
to 45,000 volts Maintains spark plug would think that two separate sub-
General Electronic Music Napoli Organ (468203) and scriptions were involved, and it
voltage to 10,000 RPM - Reduces exhaust Hyler Ignition Scope Model 326-A. Schematics. Peter
emissions - Dual ignition switch - An would start sending you two copies
Donneau, 11 Blanche Avenue. Cumberland, RI 02864.
Unconditional LIFETIME GUARANTEE Of POPULAR ELECTRONICS each month.
Installs in 10 minutes on any car with Craig Electronic Notebook Model 490. Recording Tapes. Other examples of combinations of
12 volt negative ground - No rewiring - Most Paul Chance, 17990 Graystone Lane. San Jose, CA names that would confuse the com-
powerful, efficient and reliable Solid State 95120. puter would include: John Henry
Ignition made. Smith and Henry Smith; and Mrs.
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SATISFACTION GUARANTEED or money 1030 -T. Schematic. Robert Remes, 813 N. Noland, Inde- differences in addresses can also
back pendence, MO 64050. lead to difficulties. For example, to
TIGER 500 assembled $53.95 the computer, 100 Second St. is not
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TIGER SST assembled $42.95

ii
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your name and address exactly as
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P.O. Box 1727 C This will greatly reduce any chance
Grand Junction, Colorado 81501 E.H. Scott 6 -Band (150 kHz to 80 MHz) Receiver Serial of error, and we will be able to ser-
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send

your
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Wardle- Davenport Free Precision Proton Magnetome-

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Tuning capacitor or source for same. Edward Dygert, RD
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Scintillonics (Ft. Collins. CO) Radiation Detector (meter

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antennas, masts, towers, rotors, SONY FISHER
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No. 42,146AV $5.50 Ppd. No. 9469AV . (81/2 11 PPRBK) $24.95 Ppd.

WHICH ARE YOUR

PRO ELECTRONIC
CRITICAL DAYS?
SOUND CATCHER Can Boo- rirytiun tell you? .0e're not sure, b,iì
Parabolic mike wi 18 -3/4" reflecting shield we're told that vast mood shifts are caused by
your body's Internal Time Clock whose
& 2 I.C.'s in amplifier magnifies signals rhythms can be charted ahead to possibly
100X that of omni- directional mikes. Catch warn you of "critical" days. Some are great.
a songbird ',a mile off; OB's huddle strategy; some blah. Maybe it's your physical, emo-
sounds never before heard. Super directivity tional & Intellectual rhythms converging at
the right or wrong time. Compute your cycles
gives highest signal to noise ratio poss. Safe; auto. cuts off ear damaging noises. with our Bro- rhythm kit and judge for your-
Earphones, tape recorder output, tripod socket. Req. two 9v trans. bait. (not inch. self. Inds Charting kit, metal Dialgraft Calc.,
instrs.
No. 1649AV ... (51/2 LB.) $299.00 Ppd. Stock No. 71,949AV $14.50 Ppd.
BIG EAR "TOY" MODEL e80,176AV $32.25 Ppd. 1 YR. PERSONALIZED REPORT BY COMPUTER
Stock No. 19,200AV ... (send Birthdate) $15.95. Ppd.

SUPER POWER FOR CAN'T SLEEP, RELAX?

ANY AM RADIO TRY THIS!
Electronic sound conditioner simulates 4
New antenna assist turnsa tiny transistor into a
kinds of soothing sounds of ocean surf and
tiger, has pulled in stations 1000 miles away! rain. "White sound" helps mask unwanted
a
Just set it beside your radio (no wires, clips, noise, adds restful, intriguing background
grounding) and fine -tune Select -A- Tenna's dial sound. Program the solid -state unit to
to same frequency -
"Gangbusters "! your own need: 2 surf, 2 rain or 'white
.

sound ', proven by medical tests to have

analgesic effects. Great for meditation, restlessness, sleeplessness psychology.
Terrific for sportsmen, vacationers. Great for clearing weak signals in radio de-
pressed area, off-coast islands, stations in crowded frequencies. Solid state - (A) -No. 71,997AV ...
(71/2 c 7 . 31/a") 110V AC $79.95 Ppd.
uses no electricity, batts., tubes. Works almost forever. (B) -AS ABOVE, BUT "WHITE SOUND" ONLY
No. 71,980AV... (6" Rd. n31/2" Hi) $28.00 Ppd.
Stock No. 72,095AV $15.95 Ppd.

MAIL COUPON FOR

GIANT FREE EDMUND SCIENTIFIC CO. 300 Edscorp Building, Barrington, N.J. 080t.

EDMUND
CATALOG! PLEASE SEND GIANT
How Many Stock No. Description Price Each Total

164 PAGES MORE THAN FREE CATALOG "AV"

IComplete
of electric
4500 UNUSUAL
BARGAINS
1975 ednun. New items, categories, ,II mot ons Dozens
electromagnetic parts, accessories. Enormous selection of
Charge my BankAmericard
IT Charge my Master Charge *Add Handling Chg.: $1.00. Orders Under
$5.00, 500, Orders Over $5.00
Astronomic Unique lighting and ecological items Micro- Interbank No.

IIIIIl ter®
scopes. Binoculars, Magnifiers, Magnets, Lenses, Prisms. Hord- to -get- I I 1

` °' I enclose check El money order for TOTAL S

ma
surplus bargains. Ingenious scientific tools. 1000's of components.
My Card No. Is
EDMUND SCIENTIFIC CO.
300 ilding, Barrington,
Please rush Free Giant Catalog "AV"
N. 1. 00007

Card Expiration Date

II I
Signature
Name Name
30 -DAY MONEY -BACK GUARANTEE.
Address You must be satisfied or return Address
State z.p
any purchase in 30 days for full
refund. $15.00 minimum City State Zip
L[r
CIRCLE NO. 21 ON FREE INFORMATION CARD
SEPTEMBER 1975 95

www.americanradiohistory.com
 ELECTRONICS MARKET PLACE
NON -DISPLAY CLASSIFIED: COMMERCIAL RATE: For firms or individuals offering commercial products or services, $1.80 per word (including name and
address). Minimum order $27.00. Payment must accompany copy except when ads are placed by accredited advertising agencies. Frequency discount; 5% for 6
months; 10% for 12 months paid in advance. READER RATE: For individuals with a personal item to buy or sell, $1.10 per word (including name and address.)
No minimum! Payment must accompany copy. DISPLAY CLASSIFIED: 1" by column (2 -1/4" wide), $215.00. 2" by column, $430.00. 3" by column, $645.00.
1 1 1

Advertiser to supply cuts. For frequency rates, please inquire.

GENERAL INFORMATION: First word in all ads set in bold caps at no extra charge. All copy subject to publisher's approval. All advertisers using Post Office
Boxes in their addresses MUST supply publisher with permanent address and telephone number before ad can be run. Advertisements will not be published
which advertise or promote the use of devices for the surreptitious interception of communications. Closing Date: 1st of the 2nd month preceding 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.
WE SELL CONSTRUCTION PLANS. TELEPHONE: DIGITAL ELECTRONICS! Highly effective course brings
FOR SALE Answering Machine, Speakerphone, Carphone, immediate results, $10.00. Satisfaction or $11.00 refunded!
Phonevision, Auto Dialer, Touch Button Dialer, Central Plans, Projects, Free Literature. DYNASIGN, Box 60A7,
Dial System. TELEVISION: $35.00 Color Converter, Video Wayland, Mass. 01778.
FREE! Bargain Catalog- I.C.'s, LED's, readouts, fiber Tape Recorder. $25.00 Camera. HOBBYIST: Electron UNSCRAMBLERS: Fits any scanner or monitor, easily ad-
optics, calculators parts & kits, semiconductors, parts. Microscope, 96 Hour Tape Music System, Ultrasonic Dish- justs to all scrambled frequencies. Only 4" square $29.95,
Poly Paks, Box 942PE, Lynnfield, Mass. 01940. washer, Radar -Oven, Plans $4.95 each. NEW ITEM: $75. fully guaranteed. Dealer inquiries welcomed. PDQ
GOVERNMENT Surplus Receivers. Transmitters, Electronic Pocket Calculator, $7.50. COURSES: Telephone Electronics, Box 841, North Little Rock, Arkansas 72115.
Snooperscopes, Radios, Parts, Picture Catalog 25 cents. Engineering $39.50. Detective Electronics $22.50,
Integrated Circuit Engineering, $49.50. NEW SUPER ELECTRONIC parts, low prices, free flyer: DARTEK ELEC-
Meshna, Nahant, Mass. 01908. TRONICS, Box 2460, Dartmouth. Nova Scotia, Canada.
HOBBY CATALOG plus year's subscription to Electronic
LOWEST Prices Electronic Parts. Confidential Catalog U.S. Inquiries.
News Letter AIRMAILED $1.00. Don Britton Enterprises,
Free..KNAPP, 3174 8th Ave. S.W., Largo, Fla. 33540.
6200 Wilshire Blvd., Los Angeles, Calif. 90048.
ELECTRONIC PARTS, semiconductors, kits. FREE FLYER.
MECHANICAL, ELECTRONIC devices catalog 10 cents.
ELECTRONICS SUPERMARKET
Large catalog $1.00 deposit. BIGELOW ELECTRONICS,
Bluffton, Ohio 45817.
Greatest Values -
Lowest Prices. Fertik's, 5249 "D ", 65teeo.$55 001+05
srsl x MN r e SW

RADIO -T.V. Tubes -36 cents each. Send for free catalog.
Philadelphia, Pa. 19120. 120100, 1149002 DIODES ,. ,u SOCKET

SOUND SYNTHESIZER KITS -Surf $12.95, Wind $12.95,

N
i i iii
Cornell, 4213 University, San Diego, Calif. 92105.
Wind Chimes $17.95, Electronic Songbird $6.95, Musical 0. .
$.N
AMATEUR SCIENTISTS, Electronics Experimenters, Accessories, many more. Catalog free. PAIA Electronics,
91,13 D11,1
n,aa,
I NA003
rvaErn ,, t
12

Science Fair Students... Construction plans -Complete, Box J14359, Oklahoma City, OK 73114. RESISTORS '.wSat
"` Are YOU o mailing list?
including drawings, schematics, parts list with prices and

-- - - - BUGGED ? ?? New locator finds them fast. Write, Clifton, CALL TODAY FOR YOUR...
sources. Robot Man Psychedelic shows Lasers ONLY ixió ïm
EmotionlLie Detector Touch Tone Dial Quadraphonic
11500-L N.W. 7th Avenue, Miami, Florida 33168.
- '1--DISCOUNT -i.) FREE CATALOG
Adapter
Sound Meter
- Transistorized Ignition -Burglar Alarm
over 60 items. Send 50 cents coin (no
B &K, SENCORE,
PRICES
LEADER, RCA
stamps) for complete catalog. Technical Writers Group,
Box 5994, University Station, Raleigh, N.C. 27607. EICO, FLUKE and HICKOK
METERS -Surplus, new used, panel or portable. Send for Test Equipment
list. Hanchett, Box 5577, Riverside, CA 92507. ICC /Servicemaster, RCA and Raytheon Tubes
Complete line of electronic supplies
TELEPHONE "BUGGED "? Countermeasures Brochure Free Catalog
$1.00, Negeye, Drawer 547, Pennsboro, W. VA 26415.

ALTAIR 8800 USERS

,558
FORDHAM RADIO SUPPLY CO., INC.
Morris Ave. Bronx, N.Y. 10451 f
!
FREE CATALOG. Parts, circuit boards for POPULAR
DID YOU KNOW... ELECTRONICS projects. PAIA Electronics, Box C14359,
that our 4K memory board can
remember things after you pull the
Oklahoma City, OK 73114.
plug! YOU WILL SAVE BIG MONEY! Surplus, Clearouts,
that our I/O module will interface
two TV
Bankruptcy, Inventory, Deals. Catalog $1 (redeemable).
typewriters, with keyboards, a ETCOA Electronics, Box 741, Montreal, H3C 2V2. U.S.
teletype and modem, all at the same Inquiries.
time! HEAR POLICE /FIRE Dispatchers! Catalog shows
that all of our modules are 100%
compatible with the 8800 computer! exclusive directories of "confidential" channels, receivers.
that our Software is FREE! or close to it Send 10 cent stamp. Communications, Box 56 -PE,
that we deliver on time!! Commack, N.Y. 11725.
INPUT /OUTPUT CONVERT any television to sensitive. big- screen oscillo-
This one card will meet all common I/O scope. Only minor changes required. No electronic ex-
requirements. Interface your Altair with perience necessary. Illustrated plans $2.00. Sanders,
the TV Typewriter and at the same time Dept. A -33, Box 92102, Houston, Texas 77010.
a teletype or modem, plus other devices.
Two parallel input and output ports CD IGNITIONS, VHF /UHF monitors, crystals, CB radios,
One serial I/O for any teletype and /or Southland, Box 3591 -B, Baytown, Texas 77520.
EIA RS -232C device, uses a UART CRYSTALS, Scanners, $3.88, include make and frequency.
Two special ports for any imaginable
control needs G Enterprises, P.O. Box 461PC, Clearfield, UT 84105.
Serial data rate from 35 to 9600 baud ALPHA /THETA BRAINWAVE biofeedback instruments.
Full I/O handshaking provided Analog instruments from $125; digital processing systems
ORDER KIT No. 3P +S $125. from $225. BioScan, Box 14168 -E, Houston, Texas 77021.
MEMORIES SURPRISE! Build inexpensively, the most Unusual Test
Our high speed, low power static read Instruments, Futuristic Gadgets using Numerical
write memory (RAM) allows the 8800 to
run at top speed. All our memory IC's Readouts! Catalogue Free! GBS, Box 100A, Green Bank,
are 100% tested to Military STD-883! West Virginia 24944.
Each card accepts up to 4096 8 bit words. WHOLESALE Scanners, CB, Crystals, Directories,
ORDER KIT No. 4KRA SSB /AM, Catalog 25 cents. G- Enterprises. Box 461P,
4KRA -4, w/4096 8 -bit words $215.
4KRA -2, w/2048 8 -bit words $135. Clearfield, Utah 84105.
Our PROM card accepts up to eight LEARN DESIGN TECHNIQUES. Electronics Design
1702A or 5203 erasable programmable Newsletter. Digital, linear construction projects, design
read only memories. All necessary 8800 theory and procedures. Annual subscription $6.00, sample
interface logic is provided but NO copy $1.00. Valley West, Box 2119-B, Sunnyvale, California
PR OM's. 94087.
ORDER KIT No. 2KRO $ 50.
TELEPHONES UNLIMITED, equipment, supplies. Catalog
Write for assembled unit pricing Send 50 cents. Box 1654E, Costa Mesa, Calif. 92626.
for our FREE flyer or order now from:
PROCESSOR TECHNOLOGY CO. SURPRISE! SURPRISE! Digital Piano Tuning Device tunes
musical instruments Accurately! Perfectly! Inexpensively!
2465P Fourth St., Berkeley, Calif. 94710 Construction -Instruction -Plans Complete $12.95 Airmailed
(415) 549 -0857 Postpaid! Moonlighting quickly repays $40 electronics in-
Terms: All items postpaid if full pay- vestment! GBS, Box 100P, Green Bank, West Virginia
ment comes with order. Calif. residents 24944.
add sales tax. COD orders must include
deposit. Discounts: 5% orders over PYROTECHNICAL chemicals, casings, fuse, tools,
25%
$375; 10% orders over $600. literature, supplies. Catalog -50 cents, with samples -
$2.00. Westech, Logan, Utah 84321.

CIRCLE NO 44 ON FREE INFORMATION CARO

96
www.americanradiohistory.com
PART OR PACKAGE
TERMINAL COMPONENTS FOR YOUR SYSTEM OR OURS
PACKAGE FOUR
C -MOD 8 Minicomputer(Order: RM C8)

a®®unst
ia@itf#1ilItAla®ul1
®ngaAfQ asa
mann am anani
í## .Tr
_.
Introducing the C-MOD 8 in conjunction with the RM
Terminal unit - a second generation system based on a
design of an 8008 system originally developed by
Microsystems International, called the MIL Mod 8. The
system offered is a minimum system, priced less memory,
and consists of a CPU and address latch board, and an
amsom_n_

interface board to the RM Terminal. Comes with

plated- through hole PC boards, all TTL, 8008, resistors,
Baudot Keyboard (Order: RMK) caps, and the RM terminal as
Micro Switch Hall effect solid -state keyboard manufactured by Honeywell - no
contacts or parts to wear out - 51 keys and two special direct control keys plus
16 additional encoded keys. NEW. 5 volt supply, 8 level
Baudot code. Add $1.50 for shipping, handling, insurance.
Baudot -ASCII Keyboard (Order: RMKA)
$44.50
described, and a backplane
with 6 connectors.

PACKAGE FIVE
4995
With plug in conversion board to ASCII code, including lower case, and ASCII C -MOD 80 Minicomputer (Order: RM C80)
control functions. Custom encoding and new custom key Introducing the new C -MOD 80 system - the 8080 version of
tops will be available. Add $1.50 for handling, shipping, $54.50 the system above featuring faster processing times and twice
insurance.
as many instructions, the minimum system is offered - A
CPU board and an interface board to the RM terminal,
PACKAGE ONE (Memory, and other input and output cards extra - see below)
TV Terminal III (Order: but comes with backplane with 6 connectors, all TTL, the

4900
RM TVT)
A complete I/O device- our RM Terminal unit using the case, famous 8080 8 bit CPU chip,
keyboard, (combination Baudot or ASCII code), power resistors, capacitors, in corn -
supply, the complete RM terminal, and including our TV bination with the RM Terminal
TERMINAL III kit of parts and PC boards, including all IC's, described below.
transistors, memories, resistors, caps. The display terminal
is an improved version of the device described in February,
March, April issues of Radio -Electronics. Complete RM
terminal and TV Terminal III. Riker -Maxson Terminal (Order: RMT)
Add $5.00 for shipping, handl-
ing, and insurance. 95 MiniMicroMart has obtained a quantity of
new Riker -Maxson computer reservation
terminals. Complete, less teletype
printer. Contains Micro Switch
keyboard, shown above, and a panel
PACKAGE TWO of 11 push- button illiminated
Altair-TV Terminal III (Order: RM TVALT) momentary contact Dialco switches,
as well as power supply, Boxer fan,
Same as above but includes interface to Altair 8800= plug in all enclosed in an attractive
parallel I/O card (kit version) for complete input and output housing - could be used to
display capabilities. Add
$5.00 for handling, shipping,
and insurance.
7 95 house complete minicomputer
system. Also contains
complete terminal electronics, 7
PC boards ITTL logic]; it transmits a
distinct code of its own, responds to
PACKAGE THREE being polled by central computer, provides for
special formatting, and has capability of STORING and EDITING 512 eight bit
Mark 8 Minicomputer(Order: RM MK8)
words, then transmitting them on command. Unit can be used as is or
The Famous Mark 8, as described in July, 1974 modified for your requirements. Originally sold for more
Radio -Electronics (construction manual available from tiem than $3000. Add $4.00 for handling, shipping, insurance. $109.95
at $5.00) using the 8008 8 bit micro processor IC - includes Power Supply Module (Order: RMPS)
PC boards, 8008, all TTL, resistors, caps (no switches, The modular power supply is available separately. It will supply 5 amps at 5
hardware, or Memory IC's, or Memory Boards). Memory volts, with overvoltage crowbar protections. Furnishes -5 volts (regulated] and
listed separately below. Does
include input and output boards.
4 95 two windings offering 24 volts DC unregulated: When our RM Terminal is
offered with a kit, we supply necessary components to
alter the PS to supply needed voltages. NE'N.Add $2.00
for handling, shipping, insurance.
$42.50

Memory Boards For Any Above Systems Other Combination Offers

These can also be used with Mark 8, Mod 8, (also Sclebi, We will be offering the terminal units with the world famous
Altair 8800' with proper adaptation). DEC PDP -8A and LSI -11 systems - perhaps the two most
C -MOD 8 -9 board with 256 x 8 of memory $33.95 popular minicomputer systems ever introduced - featuring
C -MOD 8 -5 board with K x 8 memory
1 49.95 brand new boards, fully built, tested, and guaranteed by the
C -MOD 8 -5 board with 2K x 8 memory 77.95 Digital Equipment Corp. The PDP -8A is a 12 bit machine - the
C -MOD -6 Accomodates 4 - eight bit inputs 24.95 LSI -11 -s a 16 bit machine. The backplane and the interface to
C -MOD -7 Accomodates 4 - eight bit outputs 24.95 the RM Terminal is of our design. Please write for prices and
Please note - above boards quoted with normal speed details.
memory - 1000 ns. For 8080 based systems 500 ns memory is
recommended - please add $2 per each 256 bytes (256 x 8) of
memory ordered.

*TradeMark
C.O.D. orders will be accepted ($1 extra charge), if a 20% deposit is sent with
the order.
All prices subject to change without notice; all offers subject to withdrawal.
1
N.Y. residents add 7% tax. 1618 James Street, Syracuse, N.Y. 13203, Phone: (315) 422 -4467
CIRCLE NO. 36 ON FREE INFORMATION CARO
SEPTEMBER 1975 97

www.americanradiohistory.com
 DATA SHEETS

FREE WITH EVERY ITEM

749 IC WITH
EVERY $10 ORDER; boec/

***CO EEFO:ll **
REDUCE YOUR PROJECT COSTS dndn
d
MONEY -BACK GUARANTEE "O Qg3,60i NEW
24-HOUR SHIPMENT 1.7
did /$serte
ALL TESTED AND GUARANTEED I ®DODJ9
Bill
IT j
- -.1- n7Nrerp
rat
d
063,.
_
ass
TRANSISTORS (NPNI: o,,
2N3563 TYPE RF Amp & O c to GHz (p1.2N918)
1 6/$1.00 j 8080 cps E onics Jrd priz''b j n'
r/ 766'ndki
2N3565 TYPE Gen. Purpose High Gain (TO- 92/106) 6/$1.00
We were 1st to offer the 8008 to hobbyists over 16 I
2N3567 TYPE High -Current Amplifier /Sw 500 mA
2N3866 TYPE RF Power Amp 1.5 W @ 450 MHz
4/$1.00
$1.50
I months ago; now we're setting
powerful new 16
Ile pace again with
bit microcomputer IC Ina 40 pin DIP,
a
j
aa
4. re? rhré
n
2N3903 TYPE GP Amp & Sw to 100 mA and 30 MHz 6 /$1.00
2N3919 TYPE RF Power Amp 10-25 W @ 3.30 MHz $3.00 made by:
fnattZ MdCROCO IPUTER C§bB i
2N4274 TYPE Ultra -High Speed Switch 12 ns 4/$1.00
i YOU MAY WIN ONE OF THESE CHIPS -- SIMPLY: CATALOG
MPS6515 TYPE High -Gain Amplifier hFE 250 3/$1.00
-
i NUMBER
PRICES
Assort NM GP TYPES, e.g. 2N3694, 2N3903, etc. (15) $2.00 1)Reveol the Secret Microcomputer Co.'s true identity I DESCRIPTION 1 -10 11 -99
2N3638 TYPE (PNP) GP Amp & Sw to 300 mA 4/$1.00 Tell us in 25 words or less why you should re- 13 -0Oó1 12 pos. rt. angle connector .90 .85
2N4249 TYPE (PNP) Low-Noise Amp 1µA to 50mA 4/$1.00 ceive a f ree c hip 13 -0002 12 position wafer .70 .65
FE Ts: I If you con convince our jaded judges, in a form suit. I 13 -0003 9 pos. rt. anale connector .80 .75
N- CHANNEL (LOW-NOISE) ; able for use in finis magazine, you win.
2N4091 TYPE RF Amp & Switch (TO- 18/106) 3/51.00
I
MC14435 L MC 400..
2N4416 TYPE RE Amplifier to 450 MHz (TU -72)
295163 TYPE Gen. Purpose Amp & Sw (T0 -106)
2/$1.00
3/$1.00
I 1,1121K1 I
I
system rm
pace 3,i, Oda ND convener

w"unemeaa. $30.00
peel meters and DAIS g POWER SUPPLY CORDS
Gray $1.46 M.
2N5486 TYPE RF Amp to 450 MHz (plastic 2N4416) 3/$1.00 I FI PRINT: ALL ENTRIES MUST BE POSTMARKED BY AUG 31 AND
BE N WR HANDS BY SEP 7, 1975; ENTRIES BECOME PROPERTY I
El 00 TYPE Low-Cost Audio Amplifier 4/$1.00
i 166314 NATIONAL CLOCK CHIP
1.NE.

OF BILL GODBOST ELECTRONICS. ALL CONTESTANTS RECEIVE AI DATA

11E4866 TYPE Ultra -Low Noise Audio Amp 2/51.00 ie SHEET ABOUT OUR FIRST PRIZE. WINNER WILL BE NOTIFIED BY 415 LINEAR
TIS74 TYPE High -Speed Switch 4052 3/$1.00 OCT 1, 1975. IF YOU 009'7 WIN ANYTHING THIS TIME AROUND I
Assort. RF & GP FET's, e.g. 2N5163, MPF102, etc. (8) $2.00 FEEL TOO BAD; ENTER OUR COMING CONTEST FOR ACON-
DON'T ELECTROLYTIC CAPACITORS NE501A 2.80
P- CHANNEL:
1 PLGTE 16 BIT MICROCOMPUTER KIT. THESE CONTESTS SPOTLIGHT ei Am
PLEASE oR R w0
2N4360 TYPE Gen. Purpose Amp & Sw (TO -106) 3/$1.00 I PRODUCTS MERE INTRODUCING FOR FALL '75. SEND ENTRIES TO I
Oe 5
WORKING ie" NE555A 1.00
E175 TYPE High -speed Switch 12551(T0 -106) 3/$1.00 16 BIT CONTEST ", BOX 2355, OAKLAND AIRPORT, CA 94614. luFI VOLTS DC S A710CA .60
10 516,35.50 .16 A741V .74
SEPTEMBER SPECIALS: SURPLUS BARGAINS, Computer Accessories. Equipment, 20 116,35,50 J6 A747CA 1.10
194154 010D 30V/10mA -1N914 exc. 30 V 20 31.00 30 16 .16 A748CV .74
Energy Conservation, Technical Reports, Kits, Semi-
2N3904 NM TRANSISTOR GP Amp & Switch
2556 DUAL 555 TIMER 1 µsec to hour (DIP)
1
5/$1.00
$1.00
conductors, Specifications, 20% 90% Discounts.
Catalog 751, 50 cents. E/S Lab, Box 738, College Park.
- 50 116.35 .22
100 516,35,50 .25
A723CA
MC1468L
1.00
3.90
2N2222 NPN TRANSISTOR GP Amp &Switch 5/$1.00
292907 PNP TRANSISTOR GP Amp & Switch 5 /$1.00 Maryland 20740. 200 16 22 Red Led A Mtg. Rrdware
2N3553 RE Power Amp 5W@ 150 MHz, 10W@ 50 MHz $2.00 500 16 .34
ALTAIR OWNERS-we have accessory boards, corn -
BUILD IN ONE HOUR! 1000 16 .52
ponents, memories, etc. Boards, IC Kits for most popular -10 11-100
0 -DIGIT MEMORY CALCULATOR KIT -Pocket size, 5 function 2200 16 1
minis. Mini Micro Mart, 1618 James, Syracuse, NY 13203. $Peeler ONE '80 .35
-x +10, addressable 5 I .29
memory with individual recall plus constant
and floating decimal. Timed display turnoff (saves batteries). Easy MINIATURE FILM CAPACITORS ill
to assemble. Everything you need -ICs, keyboard, LED array, hand-
some case, etc.; just add solder and batteries.
LINEAR IC's:
$19.95
AUDIO PROGRAM CONTROL CENTER
$14.95 PPD. USA
10 inputs,
out- 4
E _`
y VA
ILWE
.001
.0047
1.14
.10
.10
PRICE
CET
.10
.10
0B-E
A
51100
.09
.00
308 Micro -Power Op Amp (T0- 5/MINI -GIP) $1.00 puts. Switch TV, Nose vnn, ere made
.01 .10 .10 .5
309 K Voltage Regulator 5 V @ 1 A (T0 -3) $1.50 .14 .17 .15
Short -Wave, Ham, Or ire,eoon Con '
.1 .24 .21 .20
324 Quad 741 Op Amp, Compensated (DIP) $1.75 FM to Stereo Ampli- pants
on Con ter .22 .2e .29 .25
,tern too v
380 2-5 Wett Audio Amplifier 34 dB (DIP)
555X Timer 1 js -1 hr. Oil. pinout from 555 (DIP)
$1.29 fier & Recorder.
$ .85
POWERCOM CORPORATION Listen & Record. FIXED POWER SUPPLY KITS
709 Popular Op Amp (DIP/TO -51 $ .29
723 Voltage Regulator 3-30 V @ 1 -250mA (DIP/TO -5) $ .58 Box 454 Dept 4 Troy, N. Y. USA 12181 4Fadltarr,,: EOM 91210
739 Dual Low -Noise Audio Preamp/Op Amp (01P) $1.00 Iput voltage 150500011 105 125e 105.125v 110125e
DIGITAL
1458 Dual 741 Op Amp (MINI -DIP) $ .65 Output Voltage 5. t 5% 12v r 5% lye t 5%
POLICE, Fire monitors, scanners, crystals discount priced. auto. Current Cr. 25° Cl 1.5A Mar. 1.5A Mae. 1.1A Mar. CNtCUITs
741 Freq. Comp. OP AMP (DIP/TO -5 /MINI -0IP) 3/$1.00
New crystal -less scanners. Box 19224, Denver, CO 80219. PRICE 514.00 $11.60 814.50 CATALOG
IN
DIODES: MINCES
ZENERS-400mW, Specify Voltage 3.3, 3.9, 4.3, 5.1, 6.8, 8.2, TELETYPE EQUIPMENT for sale for beginners and exper- INDEFINITE SHORT CIRCUIT pOrECTION Prim ,rci , Predr,IAd
010 eerd, All Para and Transformer. 7400 34
9.1, 10, 12, 15, 18, 22, 24, 27 or 33V (110%) 4/$1.00 ienced computer enthusiast. Teletype machines, parts, 7402 34
7404 .34
1N3600 TYPE Hi -Speed Sw 75 V/200 mA 6 /$1.00 supplies. Catalogue $1.00 to: ATLANTIC SALES, 3730 7410 .34
193893 TYPE RECTIFIER Stud Mount 400 V/12 A 2/$1.00
1N914 or 1N4148 TYPE Gen. Purp. 100V /10mA 10/$1.00
Nautilus Ave., Brooklyn, NY 11224. Tel: (212) 372 -0349. DISPLAY BEZELS 7413 .75
CATALOG FILTER .54
D5 VARACTOR 5.50 W Output @ 30 -250 MHz, 7 -70 pF $5.00 PRICE OIMENs!OW Tlua. Seele sr. 7415
F7 VARACTOR 1.3 W Output @ 100 -500 MHz, 5-30 pF $1.00 Electronics Ns_
90650
ode COLOR
Red
1.54
$ 2.50 1.37
C
Sat resistant
.0.0c .ith .
7417
7420 .42
t.4

MAIL NOWI FREE DATA SHEETS supplied with every item from this L 91000 Red 2.55 2.00 black nuts 7447 1.40
ed. FREE ON REQUEST -749 Dual Op Amp 1$1.00 value) with every
order of $10 or more. postmarked prior to 10/30/75.
Enclosure L 91650
920-60
Rod
Red
2.05
2.70
3.W
4.00
finish. FiNeeS
nevi,
7473
7475
62
Be
92070,1 Amber 2.70 4.00 poly ia.dtYp. 7475 .49
ORDER TODAY-All items subject to prior sale and pries subject to
change without notice. All items are new surplus parts - 100% func-
$1 7.95 Ó ... -1
Per
-. 0 C
7490
740
a7
tionally tested. .97
discounts for Add A 7497 .Q
WRITE FOR FREE CATALOG offering hundreds of semiconductors not 7477
quantities osa I 6- .70
listed here. Send 104 stamp. 74192 3.70
TERMS: All orders must be prepaid. We pay postage. $1.00 handling
Port
RN
charge on orders under $to. Calif. residents add 6% sales tan. Foreign size, approximately
-
sedera add postage. COD orders - add $1.00 service charge. 3'Hx6"Ds7"W TRANSISTORS
S

ADV
LOW PROFILI Pol. le max.
Tracewell Electronic Enclosures will give your protect
These sockets we 2N3638A P .5 TO -92 .25
that look of a thoughtfully designed commercial product. front TI.
2N3643 N TO -5 -4
.5 .27
ELECTRONICS Tracewell Enclosures are beautiful blue, textured, 'e ABS 2N5133 N .05 TO-18 .25
BOX 4181 AR, WOODSIDE, CA 94062 plastic with black knobs and handle. Front and rear panels 2N5494 N 7.00 TO -220 1.05
are flat 'he" anodized aluminum for easy punching and silk 2N4401 N .60 TO -92 .60
Tel. (415) 851 -0455 14
iv
.60 TO -92 .30
CIRCLE NO. 3 ON FREE INFORMATION CARD screening. Extra panels are available. 2N4403 P
2$
Features include molded -in vertical grooves and stand- TIP32 P 3.00 TO -220 1.05
SAVE ELECTRIC POWER! offs for PC board mounting, light weight and ventila- TRIMMER MO OP 50 MOLEX PIN N
Save up to 80% electrical power with this unique. tion slots. POTENTIO- 7p I n style 9 2.00
inexpensive, portable, permanent and legal method To order, send $17.95 plus $2.00 shipping and handling s pin 52.26
applicable for shops, homes, factories, businesses. METERS
in check or money order to: Tracewell Enclosures. Inc.
farms, sites. 100% Refund Guaranteed if not scien-
Telephone and mail COD orders also accepted. Ohio
Thew ore 5/8- diameter MOLEX IC TERMINAL
tifically sound or if it employs gimmicks. thumbwto.l 100119 41.00 300 for 52.9 500 for 54.20
trimmer
Information $1.00 residents add 4% sales tax. T R A C E W E L L putent,ometees.
200 6,1.01.80 40010, 63.40 5001. 15.00

CONSUMERTRONICS CO. Tracewell Enclosures, Inc. , -II

700 for 15.80
8001orss.10
eso fer t7.40
1000 fer 0120
P.O. Boo 1399 Alamogordo, N.M. 88310 200 Montrose Way
, 'Co.
Am' of50,000 S 2.79,80
334

RECORD TELEPHONE CONVERSATIONS

ly -Unattended. Numerous other devices
Automatical-
Latest Most
-- Columbus. Ohio 43214
phone: 614 /263 -3702 ENCLOSURES.,,
VALUE` GUAM
I00 500 IK 5K 1050
REGULATOR CIRCUITS
5010 10010 500K MC7605CP 5vol regubta ms..
r Sa 1149
Sophisticated. Very Reasonable. Don't pay high mark-up MC7812CP 12 volt regulator 6 IAA me.. 2.00
prices other companies charge! Send $1.00 for information EXPERIMENTER supplies and components. Free list. PRICE TABLE MC7815CP 15volt,.,eese 1.6N MON 2.05
applied to purchase. D. Pasquerello, Highland Terrace,
Schwenksville, PA 19473.
Greiner, 2330 Rebecca Drive., Hatfield, PA 19440.
ELECTRONIC COMPONENTS, Meters, Government Sur-
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16 Page DIODES
plus Receivers. Catalog Free. Ed French, P.O. Box 249, Catalog 1N4001 ...., 14/51.00
VOICE DESCRAMBLERS, works with all scanners, several ERMe MOO Mln. Order. 154002 $11.00
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196401
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98 POPULAR ELECTRONICS
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 C-MON WAVEFORM GENERATOR LEDs
DISPLAYS

1
e
1-9 10 up
XR205K KIT Only $25.00 DUAL
400046 .26 .25 OPCOA O .125" dia.
400146 .26 .25 Herne a highly versatile lab in-
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EP 9125
400246
400446
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5.83
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40064E 1.35 1.34 two XR205 IC's, date & applica- V¡p=6mV SLA7 Red 1.60 $7.90
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40084E 1.79 1.78 ready for assembly) and detailed lb= 2000 nA DL80 Red 6.00 compact, thin PC
400946 .60 .59 216 Red .25
instructions. Noise" 1.5dB DL81 Red 6.00 package 216 Yellow .30
401046 .59 .58
$2.20 DL10 Red 6.00 wide viewing angle 216 Green .30
401146 .26 .25 DL1OA Red 4.00
401246 .26 .25 DL101 Red 4.90 .200" dia.
401346 .47 .46 7400N TTL PKOPEIC DL57 Red 9.90 OPTOISOLATORS 220 Red .25
401446 1.49 1.48
7400N $.13 7444N $1.05 DL61 Red 12.00 220 Yellow .30
40154E 1.26 1.25 7496N $.85 74161N 1.28 MONSANTO
7401N .17 7445N .93 74100N 1.30 74162N 1.50 DL33 Red 4.00 220 Green .30
40164E .56 .55
7402N .14 7446N 1.10 DL44 Red 6.00 MCT2 1.35
40174E 1.20 1.19 74104N 1.25 74163N 1.48 LOW PROFILE
7403N .17 7447N .88 74105N .45 74164N 1.22 DL402 Red 4.00 LITRONIX
40184E 1.491.48 7404N .20 7448N 1.00 DL701 Red 3.40 L1 1.30 226 Red $.25
40194E .52 .51 74107N .40 74165N 1.78
7405N .20 7450N .15 74109N .75 74166N 1.50 DL704 Red 2.25 L12 1.40 226 Yellow .30
40204E 1.49 1.48 DL707 Red 2.35 L16 1.80 226 Green .30
40214E 1.34 1.33 7406N .30 7451N .20 74110N .72 74170N 2.60 THE SMALLEST
7407N .30 7453N .20 74111N .92 74173N 1.55 AC /DC POWER DL747 Red 2.50 L74 1.35 226 Orange .30
40224E 1.11 1.10 XCITON LD74 1.75
402346 .26 .25 7408N .18 7454N .26 74114N .92 74174N 1.20 SUPPLY EVER!
7409N .22 7455N .37 74115N .92 74175N 1.60 Only 1.70" x 1.00" x XAN72 Red 2.00 LQ74 3.40 5053 Red .35
402446 .90 .89 XAN52 Green 2.00 5053 Yellow .40
40254E .26 .25 7410N .18 7460N .25 74118N 1.51 74176N 1.30 0.85 ", output preset
40264E 7411N .27 7462N .37 74121N .37 74177N 1.50 ±5 %, nine models: 5053 Green .40
3.72 3.70 9300 SERIES 5053 Orange .40
40274E .60 .59 7412N .52 7464N .37 74122N .37 74180N .73 VDC mADC Price 74LS
402846 .98 .97 7413N .65 7465N .37 74123N .90 74181N 3.20 5 140 74LS00 5.50 74LS76 .92 9300PC 1.00
40294E 1.27 1.26 7414N 1.80 7470N .30 74125N .48 74182N .75 8 115 74LS01 .58 74LS78 .92 9301PC 1.20
216= MV5024
40304E .44 .43 7415N .37 7471N .49 74126N .64 74184N 2.90 10 100 74LS02 .58 74LS107 .92 9304PC 1.50 5053 = MV5053
40334E 3.01 3.00 7416N .22 7472N .32 74128N .94 74185N 2.29 12 90 $39.80
ea.
74LS03 .58 74LS109 .92 9306PC 6.90 111
40354E 1.27 1.26 7417N .34 7473N .38 74132N 1.74 74168N 4.90 15 70 74LSO4 .60 74LS112 .92 9308PC 2.50 MV50 Red 5.30
40404E 1.49 1.48 7420N .17 7474N .33 74136N .92 74190N 1.49 18 50 74LS05 .63 74LS113 .92 9309PC 1.60
40414E 4.06 4.05 7421N .60 7475N .60 74140N 2.50 74191N 1.20 20 35 74LS08 .58 74LS114 .92 9310PC 1.50
40424E .75 .74 7422N .27 7476N .33 74141N 1.19 74192N 11.40
22 25 74LS09 .58 74LS138 2.38 9311PC 2.30
404346 .60 .59 7423N .48 7478N .55 74145N 1.08 74193N 1.00 24 15 74LS10 .58 74LS139 2.38 9312PC 1.20 1 -AMP RECTIFIERS
404446 .60 .59 7425N .34 7480N .60 74147N 2.35 74194N 1.35 74LS11 .58 74LS151 2.10 9314PC 1.30
7426N .25 7481N 1.19 74148N 2.20 74195N .80 10 100 1000
404746 3.54 3.53 7427N .31 7482N .90 74150N .99 74196N 1.90 1024 -BIT 74LS15
74LS20
.58
.58
74LS153 2.38 9316PC 1.50 1N4001 1.00 7.00 60.00
40484E 1.43 1.42 74LS157 2.10 9318PC 2.30
40494E .52 .51 7428N
7430N
.52
.20
7483N
7484N
.65
3.02
74151N
74152N
.75
1.50
74197N
74198N
.80
2.00
N- Channel 74LS21 .58 74L$158 2.40 9321PC 1.20 1N4002
1N4003
1.10
1.20
8.00
9.00
70.00
80.00
40504E .52 .51 RAM 74L522 .58 741_5160 2.70 9322PC 1.30
4051AE 1.34 1.33 7432N .25 7485N 2.50 74153N 1.05 74199N 2.09 74LS27 .64 74LS161 2.70 9324PC 2.00 1N4004 1.30 10.00 90.00
40524E 1.34 1.33 7433N .62 7486N .36 74154N 1.48 74200N 5.90 74LS30 .58 74LS170 5.92 1N4005 1.40 11.00 100.00
7437N 7489N 2601 -1 11.40 9328PC 2.50 1N4006 1.50 12.00 110.00
40534E 1.34 1.33 .36 2.40 74155N 1.08 74221N 1.75 2601 -21 11.40 74LS32 .64 74LS 174 3.02 9334PC 2.95
40554E 7438N .35 7490N .54 74156N 1.18 74251N 1.75 74LS38 74LS175 2.90 1N4007 1.60 13.00 120.00
2.68 2.58
7439N 7491N 74157N 26028 8.00 .65 9338PC 3.30
40564E 3.43 3.39 .39 1.00 1.18 74278N 2.95 2602 -1B 8.00 74LS51 .58 74LS181 3.72 9340PC 5.00
40604E 1.50 1.49 7440N .16 7492N .60 74158N 1.44 74279N .99 2602 -28 8.00 74LS54 .58 74L$251 2.55 9341PC 4.10 PHASE- LOCKED
7441N .95 7493N .60 74160N 1.50 74293N .95
40664E .90 .89
7442N .69 7494N 1.20 74298N 2.24
MK4102P 11.40 74LS55 .58 74LS253 3.05 9342PC 1.15 LOOPS
40694E .78 .68 7552 -1CPE 8.00 74LS73 .92 74LS260 .58 9360PC 1.75
40714E .26 .25 7443N .95 7495N .80 7552 -2CPE 8.00 74LS74 .92 LM567CM Mini dip $1.70
9366PC 1.75
40764E 1.68 1.48
40814E .26 .25
45084E 2.30 2.20 DECODED
451046 1.98 1.78
45164E 2.30 2.20 READ/WRITE PREMIUM QUALITY COMPONENTS INTERFACE MODULES
Instr. Amp., Bipolar Input 29.00

®
46184E 3.28 2.98 CY1010
45204E 1.88 1.68 RAM We've been buying and selling top quality components for nearly CV 10114 Instr. Amp -, Bipolar Input 49.00
45284E 2.30 2.20 CY1020 nstr. Amp., FET Input 34.00
P1103 I

49014E .43 .36 ten years. Our annual volume exceeds $3 million. CY1021 Instr. Amp., FET Input 49.00
49114E .43 36 CY1021A Instr. Amp.. FET Input 59.00
We handle only original parts, from the world's CY2137 DAC, 10 Bit, Low Drift 39.00
745158N 2.40
SCHOTTKY TTL 74S160N 4.70 leading manufacturers and our customers include CY2218 DAC, 12 Bit, Z Quad Multiplying 149.00
.45 74S74N 1.30 745161N 4.70 CY2237 DAC, 12 Bit, Low Drift 69.00
74SOON some of the largest and most quality- conscious CY2735 DAC. 4 Digit BCD, Low Coat 79.00
74S02N .80 74585N 6.10 74$174N 3.30
74S03N .75 74586N 2.70 745175N 3.30 companies. Now you can take advantage of our CY3035 ADC, 8 Bit, Sect. Counting,
74SO4N .75 745112N 2.20 748181N10.20 Low Cost 89.00
74S08N .80 74S113N 1.50 745189N 5.10 component buying skills and power and select CY3635 ADC, 3 Digit BCD, Sect. Count,
7481 ON .75 748132N 3.60 745194N 3.30 from a broad range of advanced circuits. Low Cost 119.00
74511N .65 74S133N .90 745195N 3.30
74820N .80 74S138N 2.40 745251N 2.40
74830N .80 745139N 2.40 745253N 2.40 AUDIO AMPS IC SOCKETS LINEAR Ks
74832N .80 74S140N .90 746257N 2.40
74540N .80 74S151N 2.40 74S258N 2.40 Type V W 52 Price SOLDER H=T05 N=DIP D=CER-DIP K=T03
74851N .80 745153N 2.40 745260N .90 TIN -24 25 100
LM352 6.15 1.15 8 1.60
1
LM114H 3.00 LM311 H 1.70 LM711CN .90
74S64N .80 74S157N 2.40 748280N 5.70 LM354A 6-27 2.80 8 2.50 8 pin DIL .21 .19 .17 LM300H 1.20 LM311D 1.90 LM715CH 4.30
TAA611B12 6-15 1.15 14 pin DIL .25 .22 .20 4.60
8 1.60
16 pin DIL .28 75107 LM300N 1.20 LM311M 1.75 LM715CD
TAA621412 6-27 .25
LOW POWER 1.40 8 2.00
24 pin DIL .67 .61 .55 75107BN 2.60 LM301AH .90 LM311 N 2.00 LM723CH 90
HIGH SPEED TTL TBA641B11 6.18 2.20 4 3.00 28 pin DI ,88 .80 72 751088N 2.30 LM301AM .80 LM312H 2.70 LM723CN .75
74H00N .34 74H53N .36 TBA800 5-30 4.70 8 2.20
36 pin DI 1.09 .98 89 75109N 2.20 LM3otAN 1.10 LM318H 2.60 LM725CH 5.00
74L00N .34 74H01N .25 74H54N .36 TBA810AS 4-20 2.50 4 3.00 40 pin DIL 1.24 1.12 92 75110N 2.20 LM 301 M .90 LM324N 1.90 LM725CD 5.20
74L02N .34 74H02N .30 74H55N .36 784820 3-16 0.75 4 1.70 LM301H
75115N 2.25 .90 LM331N 2.20 LM733CH 1.40
74H04N .38 74H60N .36 TCA830 5-20 2.00 4 2.20 WIRE WRAP -GOLD LM302D 3.50 LM339N 3.20 LM733CD 3.50
74L03N .39 14 pin DIL .45 .41 .37 75138N 2.95 1.30
74L04N .39 74H05N .37 74H61N .36 TCA940 6-24 6.50 8 4.40
44 LM302N
75150N 3.1 0 1.30 LM320-5K 2.90 LM733CN
74H08N .40 74H62N .36 16 pin DIL .54 .49 LM302H 1.50 LM320-5T 2.50 LM741CH .45
74L1ON .34 SOLDER - GOLD 4.1075154N 1.25
74L20N .39 74H10N .36 74H71N .80 2.70 LM304H
75208N 1.50 LM320-12K 2.90 LM741CD
74H11N .36 74H72N .74 14 pin DIL .34 .31 .28 75234N
LM305H 1.05 LM320-12T 2.50 LM741CM .44
74L42N 1.62 16 pin DIL .37 .34 .31 2.50 .70
74H2ON .36 74H73N .90 75450N
LM305AH 1.05 LM340-05K 2.60 LM741CN
74L51N .34
74L73N .74
74L74N .89
74H21N .36
74H22N .36
74H74N
74H76N
.87
.90
2524V TEFLON
3 pin TO -5 .55
1.25
1.00
1.00
LM305N
75451N
LM306H
75452N
1.00
.95
LM340-06K
LM340-08K
2.60 LM747CH
2.60 LM747CN
1.70
.90
74L90N 1.62 74H30N .36 74H101N .80 Recirculating 512 Bit 4 pin TO -5 .65 1.00 LM307H
75453N .75 LM340-12K 2.60 LM747CD 2.50
74H40N .36 74H102N .80 LM307M .95 LM340-15K 2.60 LM748CM .55
74L93N 1.74 Dynamic Shift Register
74L95N 1.62 74H50N .36 74H103N 1.10 8áiß TO-5 ,:10 7520 SERIES LM307N 1.50 LM340-18K 2.60 LM748CN .55
93L00 1.50 74H51N .36 74H106N .95 1-24: $3.40 25 up: $3.30 10 pin TO -5 1.40 LM308H 1.20 LM340-24K 2.60 LM777CH 2.15
931_01 1.60 74H52N .36 SENSE AMPS LM308AH 5.00 LM555CM .90 LM777CM 2.10
4.00 LM308D 2.00 LM556CN 1.30 LM3046CN .95
93L08 3.20 FM STEREO 7521N 2.00 LM308M 1.20 LM709CH .45 LM3054CN 1.50
93L09 1.80
4.25 LM309H 1.75 .45 SG4501T 2.20
93L10 2.80 BIPOLAR DEMODULATOR 7523N 1.75 LM309K 1.95
LM709CN
LM7IOCH .90 SG45o1N 2.20
93L11 4.20 MEMORY MOS-LSI XR1310 $3.20 7524N 2.00 LM31oH 1.60 LM7IOCN .90 LM5000K 7.50
93L12 1.80 1.80
93L14 1.70 C3101 6.50 P11014 6.90 C2102.1 8.00 4035 4.95 7525N 4.50 LM31oM LM711CH .90
93L16 3.20 P3101 4.90 P110141 8.50 P2102-1 5.40 4102 4.95
93L18 3.50 C31014 7.30 1402AN 5.40 C2102-2 8.00 7552 4.95 MM IC POWER REGULATORS
93L21 1.50 P31014 5.80 14034H 8.00 P2102-2 5.50 7552-1 5.40 MM404H 12.00
93L22 1.80 IM5501CDE 7.30 1403AN 5.40 2505K 3.30 7552-2 5.50 MM405H 23.00 HYBRID LM335K'. 5V, 600mA 2.40
14044H 8.00 2512K 5,50 8102 4.90 MM406H 6.50 LM336K 12V, 500mA 2.90
93L24 2.80 IM5501CPE 5.80
1404AN 5.40 2521V 4.00 8102-2 5.10 MM407H 6.60 power LM337 K'. 15V, 450mA 2.90
93L28
93L34
93L38
3.70
4.00
4.20
MM556013
MM5560N
DM8599N
7.30
5.80
5.80
1405A
1506
4.10
4.00
2524V
2525V
3.40
5.30
9102PC 5.50
MM5025N20.00
MM451H 11.40
MM454F 18.00
AMPLIFIERS'
SI -1010G 10W $6.40 COM2601
-" .,
-4".*'-
93L40 6.50 93403PC 5.80 1507 4.00 2533V 8.50 MM5026N20.00 MM500H 2.00 SI -1020G 20W 9.90
93L41 6.50 1602 33.00 2602 4.95 MM5027N20.00 MM506H 3.20 51.1030G 30W 18.70 USRT
931-60 300 33.00 2602-1 5.40 MM5055N 5.50 MM507H 3.20 81.1050E 50W 24,90
93L66 2.70 TWO -PHASE 02102 8.00 2602-2 6.50 MM5056N 5.50 MM550H 5.90 S¡ -10500 50W 24.90 UNIVERSAL SYNCHRONOUS
MOS CLOCK P2102 5.00 3341PC 8.20 MM5057N 5.50 MM551H 5.60
MM555H 5.60 RECEIVER /TRANSMITTER
DRIVER
4034 5.50 MM6058N 5.50 POWER
from Standard Microsystems
COMPUTER MHOO26CN $5.50 XR-215 PHASE TRANSISTORS STR, BSC, bi sync and interleaved bi -sync modes
INTERSIL 8038 LOCKED LOOP BU204 3A 1300V 54.14 of operation fully programmable full or half
INTERFACE BÚ205 3A 1500V 4.95
DM8820N 2.40
PRECISION WAVEFORM For FM or FSK demodulation, duplex operation *fully double buffered *directly
freq. synthesis and tracking fit. BU206 3A 1700V 5.94 TTL compatible high speed operation low power
DM8820AN 6.90 GENERATOR & VCO ser applications. 5 to 26V from 80207 6A 1300V 5.85 PRICE: 1 -9 10 up
DM8830N 2.40 For simultaneous sine, square 0.5Hz to35MHz. Accepts ana- BU208 6A 1500V 6.93
DM8831N 5.20 COSA 2601 $30.00 $24.00
and trianguler waveforms G.001 log signals 300mV to 3V. In- BU209 6A 1700V 8.64
DM8832N 6.00 Hz to 1MHz. terfaces with DTL,TTL & ECL
N8T268
9600PC
9601PC
4.40
1.30
1.20
ARP
A PORTABLE
4% DIGIT
Part No.
8038CCPD
1 -9

$3.90
10 up
$3.70
1-9
$6.56
25 up
$5.74 ^°
tTTTTTTTfl;TTm-:
COM2502
9602PC 2.10
MULTIMETER
iT UART
9614PC 2.30 MINIMUM ORDER: $10.00. Add$1.00 to cover postage and handling.
9615PC 2.40 FOR $299.
SEND CHECK OR MONEY ORDER TO:
UNIVERSAL ASYNCHRONOUS
96160C A 10 MHZ

art
5.00 RECEIVER /TRANSMITTER
9617PC 3.50 COUNTER OPTION California residents add 6% sales tax.
9620PC 4.00 FOR $50. from Standard Microsystems
9621PC 4.00
Direct TTL compatibility full or half duplex op
PULSE eration fully double buffered fully program-

gabli GENERATOR
Intlesign 1101: 0.1Hz -2MHz, MAIL ORDER: P.O. BOX 2208P, Culver City, CA 90230
Visit our Electronic Shop: 11080 Jefferson Blvd., Culver City, CA
mable high speed operation
PRICE:
COM2502P 8.00
1 -9
COM2502 $13.20 $10.60
tri-state outputs
10 up

6.85
0 -5V Output, ver. width line or
battery operation. $159.00 Phone Order: (213) 641 -4064 SPECIFICATION SHEETS: 5.25 ea.

CIRCLE O. a ON FREE INFORMATION CARD

SEPTEMBER 1975 99

www.americanradiohistory.com
 BUILD THAT ELECTRONIC ORGAN YOU ALWAYS
POTTER WANTED AT A PRICE YOU CAN AFFORD. Third edition of
a

T,,6111, "Organ Builder's Guide," pictured product kit line, cir-

BRUMFIELD
N +
C STEREO TV
1! cuits, block diagrams, design rationale using IC divider
Type Relay
'

i,!, KHP
1I 4 PDT 3A Contacts and independent generators with diode keying. $3.00 post-
,Olt .13f. 24 VDC coil) $1.50 EA.
(650 paid. Also, free brochure on keyboards. DEVTRONIX The TE -200 TELEDAPTER EASILY CONNECTS TO ANY TV 8
ORGAN PRODUCTS, Dept. C, 5872 Amapola Dr., San STEREO SYSTEM. Using our coupling and matrix circuit. teledepter takes
120 VAC (10.5 MA coil) $1.75 EA. a Imo impedance output from the television and delivers two HIGH
Jose, CA 95129. IMPEDANCE CHANNELS OF SIMULATED STEREO. to drive any
amplifier. Frequency response ,s maintained so you an hear the tinkle of
DIP 50[MET5 TTL SPECIAL bells or booming bass sounds as it happens on TV. With service warrant,
and hookup instructions $19.95 ppd. Guaranteed to make your TV 100,
PIN PCB
8 .22 7400 DIP TTL Signetic/ HYBRID AUDIO AMPLIFIER more enjoyable.
PIN PCB
14 .26 House Numbered EPITEK Model 1240 OUR NEW TE.300 VHF.UHF TELEVISION High Fidelity AUDIO
16
PIN PCB .30 TUNER is now available. Completely sohd.state Recording and amp
12 Watts RMS
24
PIN PCB .75 7404 DIP TTL Hex Inverter output lacks Anodized Aluminum front panel and simulated Walnut
PIN PCB
40 Signetic /House Numbered Distortion 0.6% at 12W Cabinet. 110 volt operation, 5169.95 ppd.
1.25
14 PIN WIRE WRAP .35 Price: $6.95 + 50 cents postage. SEND CHECK. M.O., MASTERCHARGE, or BANKAMERICARD NO.
Each $ .17 Ten for $1.50 and Expiration date TO- RHOADES NATIONAL CORP DEPT NO 50
(CA Residents add 6% tac) BO% 817, HENDERSONVILLE, TENNESSEE 37075.

FAIRCHILD "TRIMPOTS" L____-_,_*. ROYER COMPONENTS

NAME
Send Money Order P.O. Box N
Brand new 20 turn precision trimmers. These or COD Bellflower, CA 90706 ADDRESS
are prime parts mostly individually packed
in sealed envelopes. These values in stock:
50 OHM 1K 5K 25K
DIGITAL CONSTRUCTION PLANS: IC Tester, Pulse Gen- CITY STATE ZIP

500 OHM 2K 10K erator, others. Free info. T. Wong, 103 E. Bway, Dept. 40,
Each only $ .89 10 for $7.50 New York, N.Y. 10002.
MEMORIES. Prime 2101, No surplus, $4.45. Plug in com- PLANS AND KITS
CARBON RESISTORS patibility with Altair systems; superior specifications.
Carbon Resistors : -Watt 5% -full prime BankAmericard accepted. JK Electronics, Box 352, Davis,
All values in stock. 10 per value (min-
CA 95616. ATTENTION AUDIO FREAKS!! Audio Processing Cir-
imum quantity). 10 for $ .45
ELECTRONIC MUSICAL CHIME. Program any 10 note cuits designs, kits, units. Laboratory tested designs for
2102-2 MOS 1024 BIT MEMORY (DIP) melody: Plans $3.50. TV PING PONG game. Plays through hobbyist through professional use -limiters, compressors,
FULLY DECODED STATIC RANDOM ACCESS MEMORY /y` your set's antenna terminals: Plans $3.25. ARS SYSTEMS, equalizers, phasers, mixers and more! Send now-$1.00
(refundable) for complete catalog- CIRCUIT RESEARCH
DIRECTLY TTL COMPATIBLE INPUTS AND OUTPUT Box 1922K, Sunnyvale, CA 94088.
SINGLE 5V SUPPLY - - NO CLOCKS OR REFRESH LABS, 3920 E. Indian School, Phoenix, AZ 85018.
JAPANESE TRANSISTORS, all transistors original factory
$5.00 each 8 for ;34.95 made. Free catalog. West Pacific Electronics, P.O. Box AMAZING ELECTRONIC PRODUCTS -Pocket Laser, See -
25837, W. Los Angeles, CA 90025. In- The -Dark, Scramblers, Penlight Strobe, Energy Devices,
DIODE ARRAY Disruptor, Many More, All New. Catalog $1.00.
1Y I'l' l TCT'T'l'l' N UNIVERSAL TTL/DTL/CMOS IC TESTER 100,000 test oper-
ations in 0.66 seconds. Will test 16/14 Pin Digital ICs. Cir-
TV
INFORMATION UNLTD., Lord Jeffrey Drive, Box 626,
10 - 1N914 Silicon Signal Diodes in one
package. 20 leads spaced .1i'; no conmon cuit is easy to understand and build. ICs needed cost less Amherst, N.H. 03031.
connections. Each A .25 10 for $2.25 than $20.00; All are TTL. Plans $1.40: NORTHSTAR EN- CYCLOPS TV CAMERA KIT, featured on cover of February
GINEERING, 3617 North Crede Drive, Charleston, WV PE, available from CROMEMCO, 26655 Laurel, Los Altos,
Numeric Display SPECIAL
25302. California 94022.
PR
1/4" Single Digit INTEL 8080: $125.00; INTEL 8008: $25.00; TV -II KIT:
GaAsP LED
Colin CATHODE WITH RH DECIMAL
-.
I RIM
I,
PROM
$112.00 (less power supply and case). ELECTRONIC DIS-
COUNT SALES, 138 N 81st Street, Mesa, Arizona 85207.
NEW FROM EICO- Listen to official FCC -Licensed back-
ground music (SCA) on your FM radio without com-
mercials. EC5000 Kit, $12.95 Postpaid. M&K Electronic
FREE FLYER. Semis, Components, Electronic Hardware. Corp., 135 -33 Northern Blvd., Flushing, N. Y. 11354.
SUPER SPECIAL $.59 32BWORD
ACTUAL SIZE MEMORY
Lowest Prices. Vanguard Electronics, Ltd., Box 1193, DIGITAL CLOCK KIT $22.50, Frequency Counter kit, PC
TEN for $4.95
0300 EA.
Edmonton, Alberta, Canada. T5J 2M5. boards only silk screened for component mounting double
Canpact - Io digits in 3° panel width
Highly legible - bright red h" character easily read 10 - $29 UNUSUAL ELECTRONIC PLANS. Projects, Security Equip- sided, no jumpers, full instructions $25.00. New 2N4424 or
within 10 feet overr a wide viewing angle (140')
Low power - 125 aw per digit at typical brightness
yC pa RA ment, etc. Catalog $1.00. McCord Electronics, Box 276 -PE, 2N4248 or 1N5391, mixed or not 7 for $1.00. EAST COAST
rba eOL5 EA(n H
Sylvania, Ohio 43560. ELECTRONICS, 50 Scott, Hamburg, NY 14075.
RECTIFIER 1N4007 - 1 AMP - 1000 volt PRO EXCITING, high -paying jobs in communications elec-
SPECIAL! $ .13 each 10 for $1.00 tronics are opened when you get an FCC License! Just
published research report reveals best type of license to
SEND FOR C.O.D. PHONE ORDERS
get, how to get it, much more. Order Report R102 /E1, $3
postpaid. Radio Research, Box 50406, Nashville,

meae
ACCEPTED --$1O MINIMUM
FREE FLYER! Tennessee 37205.
All IC's new and fully tested, leads plated CONSTRUCTION MANUALS
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Model 740 Digital Crosshatch Generator. Compact crystal
Vista - 1 year $6.98

Payment enclosed (1 extra BONUS issue)

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 TTL EXAR I.C.'s
S N 7400 S .15 SN 74121 .38 XR -100K XRChip Custom IC Design Kit 79.00
CONVERT TV TO 7401
7402
.15
.15
74122
74123
.44
.74
XR -B101
XR -8302
NPN Transistor Array, Small Signal
PNP Transistor Array
3.45
3.45
NEW 6 FT. WIDE SCREEN! 7403
7404
.15
.18
74125
74126
.54
.54
XR -C101
XR -C102
NPN Transistor Array, Small Signal
PNP Transistor Array, Lateral 8 Substrate
3.45
3.45
7405 .18 74128 .84 XR -C103 NPN Transistor Array, Power & Schottkey 3.45
Easy Do -It- Yourself Kit 7406 .34 74132 1.45 XR -C104 Diffused Resistor Array 3.45
7407 .34 74136 .64 XR -C105 Diffused á. Pinch Resistor Array 3.45
Project a giant S'x6' picture onto wall or screen. 7408 1B 74141 .94 XR -C106 Balanced Modulator A NPN, PNP Current Source 3.45
B &W /Color. Kit contains detailed plans, Inst., and 7409 .18 74142 3.70 XR -5200 Multi- Function IC 20.95
Precision Lens System. Only $15.95 ppd., 7410 .15 74143 3.98 Xa -205 Waveform Generator IC 6.25
7411 .25 74144 3.98 XR -205K Waveform Generator Kit 24.50
or write for Free illustrated details. 7412 .30 74145 ,98 XR -210 FSK Modulator Demodulator 3.89
7413 .45 74147 2.30 XR -210M FSK Modulator Demodulator 7.75
The Macrocoma Co., Dept. DWE 7414 1.49 74148 1,90 XR215 General Purpose PLI. .91
Washington Crossing, PA 18977 7416 .33 74150 .94 XR -320 Timing Circuit 1.13
7417 .33 74151 .69 XR -555CP Timing Circuit .59
7420 .15 74153 .79 XR -556M Dual Timing Circuit 7.91
7421 .32 74154 1.09 XR -556CN Dual Timing Circuit 2.15
TESLA COIL -40" SPARKS! Plans $7.50. Information 75 7423 .27 74155 .79 XR -556CP Dual Timing Circuit 1.25
9.71
7425 .27 74156 .79 X8 -567M Tone Decoder
cents. Huntington Electronics, Box 2009-P, Huntington, 7426 .24 74157 .69 XR567CN Tone Decoder 1.37
Conn. 06484. 7427 .27 74159 3.50 XR -567CP Tone Decoder 1.25
7428 .39 74160 .99 XR -1310P Stereo Demodulator 2.39
7430 .15 74161 .99 XR- 1310EP Stereo Demodulator 2.39
MOS 60HZ crystal time base kit. 4 to 15V. Board, all parts. 7432 .24 74162 .99 XR- 1468CN +5V Tracking Voltage Regulator 2.50
$9.50. AY5 -1013A UART, $10.95, 2/$19.95. MC 1405L, 7433 .37 74163 .99 XR- 1468CP ¡SV Tracking Voltage Regulator 1.85
7437 .29 74164 1.10 XR -1488N Quad Line Driver 4.25
MC14435, 3 -1/2 digit DVM chip set with diagrams, $29.95. 7438 .29 74165 1.10 XR1488P Quad Line Driver 3.85
7440 .15 74166 1.35 XR- 1489AN Quad Line Receiver 3.55
Postpaid. Latest flyer, 10 cents stamp. TRI -TEK, 6522 N 7442 .59 74170 2.25 XR- 1489AP Quad Line Receiver 3.20
43rd Ave., Glendale, AZ 85301. 7443 .85 74172 8.75 XR3568M .0.5 Volt Tracking Voltage Regulator 10.73
7444 .85 74173 1.35 XR1568N Y15 Volt Tracking Voltage Regulator 5.35
7445 .79 74174 1.15 XR1800P Stereo Decoder 2.39
FREE CATALOGUE KITS, COMPONENTS. Audio equip- 7446 .87 74175 .99 XR -2206N Monolithic Function Generator 8.35
ment, Sinclair Kits, radio parts. Gladstone Electronics, 7447 .a7 74176 .79 XR -2206P Monolithic Function Generator 7.67
7448 .85 74177 .79 XR- 2206CN Monolithic Function Generator 4.61
1736 Avenue RD., Toronto, Canada, M5M 3Y7. U.S. 7450 ,15 74178 1.95 XR- 2206CP Monolithic Function Generator 3.83
7451 .15 74179 1.95 XR -2207M Voltage- Controlled Oscillator 11.50
Inquiries. 7453 .15 74180 .79 XR -2207N Voltage -Controlled Oscillator 5.81
7454 .15 74181 2.40 XR -2207P Voltage-Controlled Oscillator 5.03
7460 .15 74182 .69 XR- 2207CN Voltage -Controlled Oscillator 3.55
7470 .28 74184 1.95 XR- 22O7CP Voltage- Controlled Oscillator 2.85
BURGLAR ALARMS 7472
7473
.28
.34
74185
74186
1.85
13.95
XR -2208M Operational Multiplier
Operational Multiplier
13.30
6.65
XR2208N 5.93
7474 .34 74188 4.75 XR -2208P Operational Multiplier 4.19
7475 .49 74190 1.33 XR- 2208CN Operational Multiplier 3.89
BURGLAR -FIRE alarm supplies and information. Free 7476 .35 74191 1.33 XR-2208CP Operational Multiplier 5.67
7480 .48 74192 1.10 XR- 2211CN FSK Demodulator /Tone Decoder 5.15
catalog. Protecto Alarm Sales, Box 357 -G, Birch Run, 7481 .99 74193 1.30 XR- 2211CP FSK Demodulator /Tone Decoder
14.63
7482 .69 74194 1.05 XR -2240M Programmable Timer /Counter 6.59
Michigan 48415. 7483A .78 74195 .74 XR -2240N Programmable Timer /Counter
7484 1.95 74196 .99 XR -2240P Programmable Timer 'Counter 5.39
BURGLAR ALARM dialing unit automatically calls police. 7485 1.08 74197 .89 XR- 2240CN Programmable Timer Counter 4.67
7488 .34 74198 1.69 XR- 2240CP Programmable Timer Counter 3.59
$29.95. Free literature. S &S Systems, Box 12375C. North 7489 2.35 74199 1.69 XR -2556M Dual 555 Timer 7.91
7490 .49 74221 1.50 XR- 2256CN Dual 555 Timer 2.63
Kansas City, MO 64116. 7491 .79 74246 1.95 XR- 2256CP Dual 555 Timer 2.39
7492 .49 74247 1.85 XR -2567M Dual 567 Tone Decoder 12.70
PRESSURE sensitive miniature cable for burglar alarm 7493 .49 74248 1.75 XR- 2567CN Dual 567 Tone Decoder 5.92
7494 .79 74249 1.75 XR-2567CP Dual 567 Tone Decoder 3,88
systems. Place under carpet in any contour for intrusion 7495 .74 74251 1.40
detection or secret switching. $4.95 for twenty feet. Cable 7498 .79 74265 .85
74100 1.25 74273 2.75
Switch Corp., Box 72 -PE. West Long Branch, NJ 07764. PLASTIC POWER
74104
74105
.43
.43
74278
74279
2.45
.95 METAL
BURGLAR -FIRE ALARM components, hardware. Free 74107
74109
.34
.74
74283
74284
1.75
4.50 TRANSISTORS TRANSISTORS
catalog. Information. Silmar, 133 S.W. 57 Ave., Miami, Fla. 74110 .54 74285 4.50 TIP29A NPN IA 60V S 45 214696 5 .39 2N2222A .19
74111 .74 74290 .85 TIP30A PHP IA 60V ,49 214697 .39 282369A .19
33144. TIP31A NPN 3A 60V .52 28706 .25 282484 .24
74116 1.98 74293 .85 TIP32A PNP 3A 60V .55
1.35 74298 1.98 28708 .28 282857 .95
ALARM Equipment supplies. B &B Alarms, P.O. Box 298, 74120 1.40 74367 .95 TIP34 PNP 10A 40V .99 2N2904A .28
Newtonville, Mass. 02160. TIP35 NPN 25A 40V 1.99 28718 .25 .27
TIP36 PNP 25A 40V 2.25 28910 .27 2N2907A .24
TIP41A NPN 6A 60V .65
.75 281131 .39 283054 .9
C/MOS TIP42A
TIP47
PNP
NPN
BA 60V
1A 250V .88 281303
281304
.29
.29
283055
283137
.69
1.50
CALCULATORS CD4000
4001
S .24
.24
CD4033
4035
1.95
1.50
TIP48
TIP49
NPN
NPN
IA 300V
IA 350V
.96
.99
281305 .29 2N3250 .29
281420 .19 283253 .40
4002 .24 4040 1.24 TIP310 NPN 2A 60V .92 281613 .30 283375 4.95
4006 1.50 4041 .89 TIP121 NPN SA 801/ 1.64 2141711 .35 2143866 .98
TEXAS INSTRUMENTS CALCULATORS DISCOUNT HOT 4007 .24 4042 .79 TIP127 PNP SA 100V 2.02 281890 39 2N036 .55
4008 .99 4043 .79 TIP295S PNP 15A 60V .89 2N1893 .39 2N4234 .55
LINE Toll Free (800) 638 -8906. Phone us long distance free 4009 .49 4o44 .79 TIP3055 NPN 15A 60V .85 2N2060 2.75 2N4237 .55
4010 .49 4049 .49 2142102 .35 2145415 1.25
for the low discount price on the Texas Instruments Calcu- 4011 .24 4050 .49 2N221BA .29 285416 1.50
lator of your choice: SR -50, SR -51, SR -16, TI -2500 II, TI- 4012
4013
.24
.49
4051
4052
1.50
1.50 I.C. SOCKETS
4014 1.24 4053 1.50 8 Pin DIL 5.18 16 Pin .24
1500, TI -2500, TI -2550, TI -5050. All of the great new Texas 14 Pin DIL .22 SIL
24 Pin DIL .59
4015 1.24 4055 1,99
Instruments models. Capital Calculator Company, 701 East 4016 .49 4056 1.99
Gude Drive, Rockville, Maryland 20850. The discount super
4017
4018
1.24
1.24
4060
4066
1.99
.79 LED's & OPTO SCR's 2N5063 .32
CIO6B1 5.55
4019 .49 4069 .35 2N5064 .34
market for top brand name calculators. Mail and phone 4020 1.24 4071 .35 ISOLATORS C106D1
2N5061
.85
.28 TIC47 38
orders accepted. BankAmericard and Master Charge 4021 1.24 4076 1.24 DL707 7 Se9 0.3" 51.70 2N5062 .30
4022 1.24 4081 .35 DL747 7 Sep 0.63" 2.45
accepted. 4023 .24 4507 1.25 8L2 Red Led .19" .23
024 .99 4510 1.24 TIL2O9
TIL111
Red Led .125" .19
1.20
4025 .24 4511 2.50 Opto- Coupler
4026 1.95 4512 2.95 TIL220 Red Led .20" .24
HIGH FIDELITY 4027
4028
.59
.99
4516
4518
1.75
1.95
IL35
IL16
OptoIsolator
Opto- Isolator
1.25
1.40
LOW POWER
4029
4030
1.24
.49
4520
4528
1.95
1.50
TIL312
TIL313
7 Seg.
7 Seg.
0,3"
0.3"
1.70
1.70
SCHOTTKY
SN74L5OO S .42 5N74L5114 .68
74L501 .42 741.5122 .68
DIAMOND NEEDLES and Stereo Cartridges at Discount 74L502 .42 74L5123 .84
PLASTIC 74L503 .42 74L5125 .68
prices for Shure, Pickering, Stanton, Empire, Grado and LINEAR I.C.'s 74L504
741.505
.47
.47
74LS126
74L5132
.68
1.58
ADC. Send for free catalog. LYLE CARTRIDGES, Dept. P. LM300H Positive Voltage Regulator can TRANSISTORS 74L508 .42 74L5136 .68
Box 69, Kensington Station, Brooklyn, New York 11218. LM303AH Hi Performance Op Amp (meta .35 2N3415 S.17 74L509 .42 74L5338 1.94
LM304H Negative Voltage Regulator (meta can) .75 2N3563 .15 74L530 .42 74L5139 1.94
LM305H Positive Voltage Regulator (meta 2313564 .15 74L511 .42 74L5145 1.58
LM307H Op Amp (Super 741) mea can) .28 2N3565 .15 74LS12 .42 74L5151 1.58
LM307 mini Op Amp (Super 741) 2N3566 .15 74L513 .84 74L5153 1.94
WANTED LM309H 5V 1 Amp Voltage Regulator (mea scan) .99 2N3567 .15 74LS14 2.22 741.5155 1.94
1M309K SV 1 Amp Voltage Regulator (TO3 1.39 233568 .15 74L515 .42 741.3156 1.94
LM310H Voltage Follower Op Amp (meta can) 1.09 2N3569 .15 74L520 .42 741.5157 1.58
LM324 Quad Op Amp (DILI 1.75 2N3640 .15 74L521 .42 74LS158 1.58
QUICKSILVER, Platinum, Silver, Gold, Ores Analyzed. LM339 Quad Comparator 2N3641 .15 741.522 .42 74L516a 2.27
LM555 Timer (mini dip) 1.54 2N3643 .15 74L526 .54 74L5170 5.36
Free Circular. Mercury Terminal, Norwood, Mass. 02062. LMSSBN Dual Timer 2N3702 .17 74L527 .47 74L5174 2.27
LM709CH Op Amp (metal can) .29 2N3703 .17 74LS28 .54 741.5175 2.27
AMATEUR EQUIPMENT wanted for handicapped people in LM709 mini Op Amp (mini dip) .29 2N3704 .17 74LS30 .42 741-5181 6.30
LM709CN Op Amp (DIL) .29 2N3705 .17 74L532 .47 741.5190 2.87
Israel. Please send whatever you have to: Handicapped LM711CH Dual Difference Comparator (metal can) .50 2N3706 .17 741.533 .54 74L5191 2.87
LM723CH Voltage Regulator (metal can) .54 2N3707 .17 74L537 .54 741.5192 2.87
Workers, 43 Chefetz- Chaim, Petaah -Tiqwa, Israel. LM723CN Voltage Regulator (14 .54 2N3708 .17 74L538 .54 74L5193 2.87
LM741CH OP Amp ) ) .29 2N3709 .17 74L540 .54 741.51948 2.27
LM741 i Op Amp (mini dip) .28 2N3710 .17 74L542 1.25 74LS195A 2.27
LM741CN n Op Amp (14 2N3711 .17 741.548 1.25 741.5196 2.27
TUBES LM747CH Dual 741 Op Amp .65 2N3819
2N3820
.29 74L549 1.25 741.5197 2.27
LM747CN Dual 741 Op Amp (14 pin DIL) .75 .35 74LS51 .42 741.5221 1.41
LM748 mini Dual 741 Op Amp (mini dip) .29 2N3903 .15 741.554 .42 741.5247 1.25
LM1458H Dual Op Amp (metal can) .65 2N3904 .15 74L555 .42 741_5248 1.25
RADIO & T.V. Tubes -36 cents each. Send for free LM3046 Transistor Array .85 2N3905 .15 74L573 .68 741.5249 1.25
LM3900 Quad Amplifier .79 2N3906 .15 74L574 .68 741.5251 1.94
Catalog. Cornell, 4213 University, San Diego, Calif. 92105. 2N4058 .17 74L575 .84 74L5253 2.27
2N4059 .17 74LS76 .68 74LS257 1.94
RECEIVING & INDUSTRIAL TUBES, TRANSISTORS. All 2N4060 .17
Brands - -
Biggest Discounts. Technicians. Hobbyists.
Experimenters Request FREE Giant Catalog and SAVE! MEMORIES
2N4061
2N4062
2N4123
.17
.17
.15
741.578
74L5583A
74LS585
74L586
.68
2.27
2.88
.68
74L5258
741.5261
74LS266
741.5279
1.94
5.36
.68
.84
AY5 -1013P UART S 9.00 234124 .15 74L590 1.25 741-5283 2.27
ZALYTRON, 469 Jericho Turnpike Mineola, N.Y. 11501.
, AY5 -2378 Keyboard Encode, ROM 19.95 2N125 .15 741.591 1.25 741.5290 1.25
1101AP 256 Bit Static RAM MOS 3.95 2644126 .15 741.592 1.25 74L5293 1.25
TUBES receiving, factory boxed, low prices, free price list. 1403AT Dual 512 Bit Dyn MOS 5/R 3.75 2N4250 .15 74L593 1.25 74L5295A 2.27
1404AT Single 1024 Bit Dyn MOS S/R 3.50 2N4275 .15 74L595A 2.27 741.5365 .68
Transleteronic, Inc., 1365 39th Street, Brooklyn, N.Y. 1702A 2048 Bit Er le Elect. Reprogrammable 2N4401 .15 74L5595B 2.27 741.5366 .68
Static MOS RAM 23.95 2N4403 .15 74L596 1.94 74L5367 .68
11218A, Telephone: 212 -633-2800. 2102P 1024 Bit Static RAM MOS 3.95 2N5400 .22 .68 74L5368 .68
2N5447 .16 741_5107
8008R 8 Bit Central Processing Unit 44.00 741_5109 .68 741.5375 .84
TUBES "Oldies ", latest. Lists free. Steinmetz, 7519 8080 8 Bit Parallel CPU 195.00 2N5449 .16 741.5112 .68 741.5386 68
Maplewood, Hammond, Indiana 46324. TM54030NL 4K RAM 4096 Bit 19.95 2N5525 .39 741.5113 .68 74L5670 6.30
T1543 .39
CASH PAID FOR OLD TUBES RCA45, RCA50, WE205B,
WE252A, WE300B, WE350B, WE274A, and sound Hi -Fi
equipment of Western Electric, Macintosh, Marantz, Leak,
Quad, old and new types. Contact: M. Takabe, Room 1816,
303 Fifth Ave., NYC 10016.
FREE SELF-SERVICE TUBE TESTER -Receiving tube types
Active Electronic Sales Corp.
P.O. BOX 1035 FRAMINGHAM, MASSACHUSETTS 01701
75% plus off list. Top manufacturers. Brand new cartoned, Telephone Orders (617) 879 -0077
FREE LIST. CECO COMMUNICATIONS, 2115 Avenue X, MINIMUM ORDER $10.00 ADD $1.00 TO COVER POSTAGE & HANDLING
Brooklyn, N.Y. 11235. (212) 646 -6300.

CIRCLE NO. 64 ON FREE INFORMATION CARO

SEPTEMBER 1975 101
www.americanradiohistory.com
 PROGRAMMABLE COUNTER MOVIE FILMS

Counter used by manufacturer of copying mach- 8MM -SUPER 8 -16MM MOVIES! Biggest Selection! Lowest
ines. A number from to 99 is preset on the 2
1
Prices! Free Catalog! Cinema Eight, Box PE, Chester.
S! rotary switches. The counter will then count to
this number with each pulse. When the preset
count is reached, a voltage appears on a pin,
For Connecticut 06412.

which can trip a relay, or perform any desired ELECTRICAL SUPPLIES & EQUIPMENT
function.Readout tubes are NIXIE tubes,
BURROUGHS 5092A, currently listing for
over $15.00 ea. Requires 24 V DC & 180V DC.
faster PLATING Equipment, Portable Platers, Supplies and
"Know- How." Build your own tanks for nickel, chrome,
5 % "x5" 2 lbs. STOCK NO.P9201 $6.95 ea. 2/12.00 etc. Easy -to- install PVC liners. Rectifier components -all

LATE MODEL PARTS BOARD. service sizes. Schematics, parts lists, formulas, operating
instructions for all plating. Guaranteed to save you 25 %-
Board contains the following semicon- 75%. Some good used units for sale. Write for details.
Platers Service Company, 1511 -PE Esperanza, Los
ductors: 1 741 Op-Amp, 1 LM300 2 to Angeles, Calif. 90023.
20 volt voltage regulator,1 D41d1 6W.
G.E. PNP power tab transistor, 2
D42C5 12.5 W. G.E. power tab trans- GOVERNMENT SURPLUS
istors, 2 Motorola SJE
an SCR and a rectifier
5039 Power transistors,6 small transistors,
bridge. Plus many 'AO/ resistors, electroytic caps,
USE
diodes, a 1 K trimpot. A parts bonanza. With data sheet. GOVERNMENT Surplus. How and Where to Buy in Your
3/6.00 Area. Send $2.00. Surplus 30177 -PE Headquarters Bldg.,
STOCK NO.P9033 2 lbs,

750 WATT HIGH POWER TRANSFORMER

$2.50 ea.
ZIP Washington, D.C. 20014.
MANUALS for Govt Surplus radios, test sets, scopes. List
50 cents (coin). Books, 7218 Roanne Drive, Washington,
30 volts ct with 12 volt taps, @ 25 Amps. 750 watts of power. D.C. 20021.
Makes heavy duty + 15 volt and + 5 volt supply, or 12 volt
and 30 volt supply, or combinatióñ of above & more. We
supply data sheet showing many possibilities.
CODE RECEIVE Weekly Catalogues containing hundreds of Sur-
plus Electronics Bargains, plus "Buying Surplus"
19.95 ea. 2/38.00 $6.00 /year. Send for Free Newsletter. Insidescoop, 5050
STOCK NO.P9839 wt. 20 lbs. Roseville Road, North Highlands, Calif. 95660.
COMPUTER GRADE CAPACITORS GOVERNMENT Surplus Electronics: How, Where, Your

4000 Mfd.
7000 Mfd.
50 V. K2189
50 V. K2239
2.50 ea.
2.75 ea.
4/9.00
4/10.00 on Area, $1.50, Pennington, 6542 Fair Oaks, Carmichael,
Calif. 95608.

PERSONALS
Include sufficient postage. Excess will be refunded. Send for
new catalog 14. 64 pages of electronic bargains. MINIMUM
ORDER, $5.00.
all MAKE FRIENDS WORLDWIDE through international
correspondence. Illustrated brochure free. Hermes, Berlin

ELECTRONICS CO. mail 11, Box 110660/ZD, Germany.

WINEMAKING. Make delicious homemade wine expertly.

ADELTA BOX 1, LYNN, MASSACHUSETTS 01903

Phon. (Si?) 35$ -4705
Recipe, $2.00. GIGI. Box 220-B, Miami, Florida 33168.
UNEMPLOYMENT INSURANCE. Collect every penny. De-
tailed Instructions, $2.00. Clifton, Box 220 -A, Miami,
Florida 33168.
CIRCLE NO. 11 ON FREE INFORMATION CARO

CB SPECIALS OEM SPECIALS

1N270 .06 2N630 3.10 2811540 .90 2N2325 2.10 2N3247 3.50 2813856 .20 2N4403 19
2SC517 4.75 2SC781 3.25 2SC1237 2.00 2SC1678 5.75 1N749.A .16 2N677C 5.00 2N1543 3.00 2812326 3.00 2N3250 .40 2813866 .90 2N4409 19
2SC710 .70 2SC799 4.25 2SC1239 2.80 2SC1679 5.75 1N750.A .16 2N706 .20 2811544 .80 2N2327 4.00 2813375 4.95 2813903 .19 2N4410 19
2SC711 .70 2SC1013 1.50 2SC1243 1.50 2SC1957 3.50 1N751,A 16 2N7068 .35 2811549 1.05 2812328 4.25 2813393 .19 21(3904 .19 2N4416 75
1N914 .08 2N711 .35 2811551 3.50 2812329 6.00 2N3394 .19 2813905 .19 2N4441 85
2SC735 .70 2SC1014 1.50 2SC1306 5.25 2SD235 1.00
.50 2N1552 3.50 2812368 .25 2813414 .19 2N4442
.22 2813906 90
1N4148 .06 2N711B
2SC756 1.50 2SC1017 1.50 2SC1307 6.25 MRF8004 3.00 1N4746 .50 2N718 .18 2N1554 1.75 2N2369 .19 2813415 25 2193924
3.25 2N4443 1.25
2SC773 .85 2SC1018 1.50 2SC1377 6.75 4004 3.00 1N4747 .50 2N718A .25 2N1557 1.50 2812484 .20 2N3416 4.50 2N4852
.28 2193925 60
2SC774 1.75 2SC1173 1.25 2SC1449 3.50 4005 3.00 1N4749 .50 2N720A 1.35 2811560 3.00 2812712 .25 2813417 4.50 2N5061
.30 2N3954 .25
1N5355 .75 2N759A 90 2811605 .35 2812894 .40 2193442 4.90 2N5064 .40
1.90 2N3954Á
1N5357.A.B.75 2N760 40 2N1613 .30 2N2903 3.50 2813553 250 2N5130 .19
1.50 2813955
2K3563 2.90 2N5133 .15
JAPANESE TRANSISTORS 1N5358.A,B75 2N877
1N5359,A.B.75 2N894
201173 2.00 2N918
2.25 2N1671 1.00 2N2904
1.75 2N1711
.19 2N1907 4.25 2N2905
.19
.30 2N2904A .25
.19
.18 2193955Á
2N3565 .18 2N3957 1.30 2815138
2N3638 .18 2N3958 1.20 2N5154 6.25
.15

2N178 .90 2N930 .19 2N2060 1.90 2N2905A .25 2N3642 .19 2N4037 .60 2N5157 8.95
2SA52 .60 258370 1.10 2SC478 .80 250829 .75 2501509 1.25 .20 2N2102 .40 2192906 .19 2N3643 .15 2814093 .90 2N5198 3.85
250833 250 1569 1.25 2N327A 1.25 2N956
2SA101 .70 2513379 .65 250482 1.75 .70
2N334 1.25 281960 .40 2N2218 .20 2N2906A .20 2N3645 .15 2N4124 .18 2N5294 .60
2SÁ103 .70 258380 .70 250491 2.50 250838 .70 2501758 1.25 .40 2N2218A .25 2N2907 .19 2193646 .10 2N4126 .23 2N5296 .45
2N336 .90 2N962
2SÁ221 .60 258405 1.00250495 .70 250839 .85 25030 as .40 2N2219 .20 2N2907A .25 2N3730 1.25 2N4141 .23 2N5306 .20
25045 2.00 2N338A 1.10 211967
2SÁ473 .85 258407 210 250497 1.60 250830 .65
2N3988 .90 2N1136 1.25 2N2219A .25 2N2913 .75 283731 1.85 2N4142 ..16 2N5354 .25
2SÁ495 .65 258415 1.05 2SC515 .80 250945 .65 25064 .75
1.65 2N2221 .19 2N2914 1.25 2N3740 1.00 2N4143 .15 2N5369 .20
25065 281404 .20 2N1137A
2SÁ497 55 258461 1.25 250535 .95 2501010 .80 .75
1.05 2N1142 1.95 2N2221A .19 2N2916A 3.75 2N3771 1.90 2N4220A .90 2N5400 .50
281443
2SÁ505 65 1.65 250536 .65 2SC1012 .80 25068 .70
1.15 2N1143 1.75 2N2222 .19 2193019 1.25 2N3772 2.00 2N4234 1.25 2N5401 .50
1.00 281456
2SÁ562 .70 2584 17 1.75 250537 .70 2501013 1.50 2SD72 2N501A 3.50 2N1302 .25 2812222A .19 2813053 .79 2N3773 2.10 2N4235 1.80 2N5457 .35
2SÁ607 2.25 258474 1.75 250563 2.50 250 1014 1.50 25088 1.50
2N508Á .35 2N1305 .30 2N2270 .30 2N3054 .70 2N3819 .25 2144400 .19 2N5458 .35
2SÁ613 1.00 258481 2.10 2SC564 .70 250 1018 1.50 250 120 .85
2815128 250 2N1377 1.25 2N2322 1.50 2N3055 .75 2813823 .80 2N4401 .19 2N5467 28.00
2SA843 .85 2SB492 1.25 250568 .70 2501030 3.25 250130 1.50
281555 .45 2N1420 .18 2192328 1.60 2N3227 2.10 2N3843 .25 2N4402 .19 C10681 45
2SÁ647 2.75 258495 .95 250582 .85 2501051 2.50 250141 2.25
2N652A .90 2N1483 1.00 2N2324 2.00
2SÁ673 .85 258605 2.00 250591 2.50 2501061 1.65 250 151 2.50
2.25 2SB606 2.00 250605 1.00 2SC1079 3.95 250170 2.00
2SÁ882 .95 25C15 .65 250819 70 2SC1096 1.20 250/80 3.00 SILICON UNIJUNCTIONS INTEGRATED CIRC. RECTIFIERS
2sÁ699 1.30 2SC24 .65 250620 .80 2SC1098 1.15 250198 2.50
10 100
25Á889A 2.00 .65 250627 1.75 2501115 2.75 250201 2.50 2N2646 To-18 .50 UA703C .40
2SÁ705 .55 2SC33 .65 250644 .70 2501166 .70 250218 5.00 2N2647 To-18 .65 CA3066 4.00 1N4001 .60 5.00
2SÁ714 2.50 2SC41 4.00 2SC645 .85 2501170 4.00 2SD235 1.00 2816027 PUT To-92 .55 CA3068 6.50 1N4002 .70 6.00
2SÁ720 .70 2SC49 .80 250681 2.50 25011728425 250261 .80 2N6028 PUT To-92 .75 MC1305 1.50 1N4003 .80 7.00
2SÁ733 .65 2SC56 95 250684 2.10 2SC1173 1.25 250291 .85
2N1671 To-5 1.00
.65 2SC 143 3.50 2SC887 2.50 250 1213 .75 250292 .85 Replacement for Zenith 1N4004 .90 8.00
25822 D5E37 To-18 4/1.00
25854 .0 2SC 154 3.75 250696 2.35 2501226 1.25 250300 2.50 221 -36, 221.37, 221 -39 3.50 1N4005 1.00 9.00
25856 .70 250162 3.75 25C710 .70 2501237 2.00 250313 1.20 1814006 1.10 10.00
.70 250163 4.50 250711 .70 2501239 2.80 2513315 .75 1814007 1.20 11.00
251377
2513128 2.50 250185 1.00 250712 .70 2SC1293 .85 250318 .95 TRANSISTOR GRAB BAG
258135 .95 1.00 250713 .70 2801308 5.00 2513341 .95
258152 4.50 250206 1.00 2SC732 .70 2SC1317 .60 250350 3.50 Untested. 50/1.00 FAIRCHILD 9L00 IC's, prime units

ï
258172 55 250240 1.10 250733 .70 2501325 5.00 250352 .80 HOBBYIST'S 16 Pin Digital IC- Untested. 15/1.00 709C Hi -Peu. Op Amp 5/1.00 29
258173 55 250261 65 2SC735 .70 2SC/347 .80 250380 6.00 741C Hl -Peu. Op Amp 4/1'.00
258175 55 250291 65 2SC739 .70 25801377 6.75 250389 .95
258178 1.00 2SC320 .75 2SC756 1.50 2301383 .75 250390 .75
íi10111111ii New -Tone Electronics
ïi "
258186 60 250352 .75 250774 1.75 2SC1393 .60 250437 6.00
258187 60 250353 .75 250775 2.00 2501409 2.75 250458 .80
256235
258303
258324
1.95
65
1.00
250371
250372
250360
.70
.70
.70
2SC778
2SC783
250784
3.00 2501410
1.00 2501446
.70 2501447
2.75
1.25
1.25
2501111
2501115
251(19
3.50
3.75
2.25
IN'. is r d"` 11 wr
P.O. Box 1738 A
Bloomfield, N.J. 07003
258337 2.10 2SC387 .70 250785 1.00 250 1448 1.25 2SK30 1.25
258364
258365
65 2SC394
65 2SC458
.70
70
2SC792
250793
3.00
2.50
2501450
2501454
1.00
2.75
23K40
3SF11
1.60
3.14 Phone: (201) 762 -9020
258367 1.60 2SC460 70 250828 .75 2501507 1.25 SG609 4.95
ALL PARTS GUARANTEED AND TESTED ON PREMISES.
Terms: Check or money order. COD's accepted. Include 10% for postage and
FAIRCHILD 7400 IC -While They Last! 8/$1 00 handling. N.J. residents add 5% sales tax. Minimum order $5.00.
CIRCLE NO. 31 ON FREE INFORMATION CARO

102 POPULAR ELECTRONICS

www.americanradiohistory.com
 BUY ANY 10 9- FUNCTION, 8 -DIGIT DOUBLE MEMORY
Percent, Constant,
TAKE 15% MEMORY CALCULATOR KIT Display Restore

BUY 100 It's the easiest multi -function kit today!

Lightweight. 51/ x 3 x (2" at back aide) x 11/"
front side of angular display panel black case. Nifty
TAKE 25% unit for business, school, home, and for the youngsters.
5N741 22 .48 Slips into any pocket, briefcase with ease Easy -to-
SN741 23 .85 understand pictoral instruction booklet and how -to-
.- hook. AC /DC too!
SN741 25 .59 KIT INCLUDES: case, 22 -key keyboard kit, ON -OFF
SN741 26 .59 switch (part of keyboard) PC board, driver and memory
5N741 32 1.75 calculator chips, 9 -digit 'bubble" magnifier LED array.
SN741402.10 4. Function
array cable. AC adapter jack A wiree, battery case 6 Arithmetic
SN74145 1.05 battery card display, instruction and pictural step -by-
SN74148 2.25 step construction booklet. 22 KEYS!
SN7400 $.16 SN7462 $.22 SN74150 .98
SN7401 .16 SN7470 .29 SN74151 .75
SN7402 .16 SN7471 .49 SN74153 .90
OSN7403 .16 SN7472 .29 SN74154 1.35 THE SIMPLEST! FINEST! SMALLEST!
SN7404 .19 SN7473 .36 SN741 55 .95 IDalloncI
BRITE
SN7405 .19 SN7474
.36
SN7475
.59
SN741 56 .95
DIGITS 6- FUNCTION AC-DC
5N7406
SN7407
SN7408
O SN7409
.35
.35
.19
.19
5N7476
.39
SN7478
.79
SN7480.52 SN74161
SN74157
SN74158
SN74160
.95
.95
1.35
1.25
CALCULATOR KIT!
kit pecked in a multicolor attrac-
. Simplified Indexing
Mark up and Mark down
$13
i
SN741 0 .16 SN7481.99 The entire is even Constant multiplication
SN74163 1.35 tively designed box that in itself telle the min calcula-
SN7411 .25 SN7482.89 SN74164 1.50 tor story. Kit includes: attractive black case with red and division
SN7413 .59 SN7483 1.25 SN741 65 1.50 filtre: Flex Key (type 2OSK -66) 18 her keyboard that AC adaptor lack
SN7414 1.65 SN7485 1.25 SN74166 1.50 measures only 2'/s x 2" with 2 witches, one for ON-
SN7416 .34 5N7486 .37 SN741 73 1.45 OFF. one for K c .tant: MAIN pc board; readout Lightweight, pocket sine
SN7417 .34 SN7488 3.95 SN741 74 1.39 board: famous Cal Tech 6030 26 -pin calculator chip: Extra large display
two 75491 it drivers: 9 digit array:
SN7420 .16 SN7489 2.45 SN74175 1.30 ac iack: 9 Volt battery connector resistors: two tren-
functions plus, minus,
SN741 2 .45 SN7490 .59 SN74176 1.20 istors: back protective plate: necessary wire plugs; times, percentage, constant
SN7423 .29 SN7491 1.10 SN74177 1.20 easy instructions. (Lees 9 volt standard battery and Floating decimal
SN7425 .29 SN7492 .59 SN74180 .95 adapter) EASIEST KIT TO BUILD calu I a ti ons
al
SN7426 SN7493
C
Chain and Min
.25 .59 SN74181 2.98
SN7427 .29 SN7494 .95 0SN74182 .74
SN7430
SN7432
.16 SN7495
SN7496
.79 5N74184 1.98
4 -DIGIT AM -PM
Timer
$2.50
SN7433
.25
.49
.79
SN74100 1.40
SN74185 1.98
SN74190 1.40 o555 24V FILAMENT
SN7437
SN7438
.34
.34
SN74104
SN74105
.44
.44
SN74191 1.40
SN74192 1.25
FLUORESCENT $9.99 OR TRANSFORMERS
SN7440
SN7441
.16
1.00
SN74106
SN741 07
.52
.44
SN74193 1.25
SN74194 1.20
CLOCK PANEL D 558 Scarce and very popular.
115 vac primary 24VCT
SN 7442 .70 SN741 08 .89 SN741 95 .85 "PANEL OPTICS" Dual 741 aecondary at 600 mils.
SN7444 1.25 SN74112 .89 SN74196 1.80 Color -coded leads. 1000's
SN7445 .89 SN74113 .89 SN74197 .90 YOU ASKED FOR IT! Found only at Poly Palie at th,e 2 for $1 of low voltage ideas. Metal
5N7446 1.15 SN74114 .89 SN74199 1.75 -o -w price! Its ONLY 1 3/4 x 1 3/16 x 3/8" deep encased. 2112 x 2 x 2 ". Wt.
3 for S6
1

SN7447 .99 SN74121 .49 SN74200 4.95 panel. Designed apecifically for our MM -6316 fluoree- lb.
I

SN7448 .99 driving clock chip. Indicates 4- digits, AM -PM. Made

SN7450 .16 pulsating second indicator, requiers minimum f parte
pent
N1CAD tu build. Color: BLUE- GREEN: you c e RED or By
SN7451 .17 POWER PAK GREEN filters. Character height: 0.5". Filament volt-
SN7452 .17 Include. n "A" cell n cad age is 1.76 VAC or DC @ 160 mile. Anode voltage TUNG -SOL
SN7453 .17 bat s hooked u o `ive 25V @ 250 microamps per segment. With spec sheets,
SN7454 .17 ut 6-volts for a1Ì type. M clock c natruclion diagrama, P.C. board layout.. specs. D2004
SN7455 .22 orgy u The beet bat
.

A DIGITAL CLOCK BUILDER'S SPECIAL.

SN7460 17 tens. mane. Rechargeable.

This unit is not advertised POSTAGE STAMP LOWEST PRICES IN U.S.A.!

anywhere! Made for MONSANTO! XCITON!
MOBILE SPKR

k
Motorola Communications at NATIONAL "BLASTAWAY"
the original coat of $4.50
each (for insertion in their' MIKE $1.98 LM -340T VR's ON 1N4000
í1LITRONIX1 OPCOA!
Walkie Talkie Program) too, covering broad ca nee
It's a 60 -ohm imp MIKE.
.

in sound. Extremely well - RECTIFIER PRICES 5 for $1

It's an excellent speaker made. $1.75 Each - .340x.260 240x.200
I INDUSTRIAL SPEED CONTROL
A $30 item from G.E. Model 533A (made for /tereo,
$4.95 e.
Type
1N4001
1144002
P1V
S010
10010 for SSe
Sale
for 4Se Jumbo
Rad
Medium
Red
that controle home. shop and industrial lighting too! A LMY aaODT r 1144003 200 10 for 65c Green Yellow
y elaborate circuit for controlling many electrical LM.140.0eT 1N4004 400 10 for 75e Yellow Green
ae electronic devices. Easily controls speeds of electric for 85c Amber Amber
lit, PI
and
drills. brush type motora, etc. 115vac, rated at 1100
watts. With variable speed or dimming control in
IN4005
I144008
600
800
10
10 for 99e Clear Clear
5N4007 1000 10 for1.29
lier
heavy -duty aluminum case. 3 x 2s /y x 2. With diagram Micro 210x.128
and hookups. Red Yellow
Green Amber

,.
MICROPROCESSORS!
4% DIGIT DIGITAL VOLTMETER ROMS! RAMS!
Micro (Axial) MV -50 style
$1.
Clear 10 for
DVM CHIP MM5330
circuit for digit
Type by National utilizes P channel low- thresh-
old enchancement mode devices and ion mplanted deple-
tion mode devices. Provides logic 41/2
MEMORIES!
MV -55 Red e for $1.

DVM. All logic for four decade counters, a divide by

four counter, a divide by te'o counter for over-range
8008 Microprocessor $44.00
250.00 7- SEGMENT READOUT SALE!
output ROM 8080 Super 8008 Up to 20 mils per seg. at 5V. RAM-1
blanking, latches for all c unter stages, 2102 1024 Static RAM 3.95
t g ate BCD to 9'a complement BCD of the latches 1101 256 bit RAM 1.50 All fit lato 14 -pin IC socket.
and a module 4 counter to sequentially present each 2.95 Type Sixe Color Sale 3 for
to BCD outputs plus 1103 1024 bit RAM $2.60 $6.00
of decade latches thru ROM the MM5260 1024 RAM 2.95 MAN1 .27 Red MAN -3
four outputs to indicate which decade is display. A 31185282 2048 bit RAM 6.50 MAN -3MA .12 Red .69 2.00
reset for all counter stages. transfer pulse generator to 2513 Character generator 12.50 MAN -4AB .27 Red 1.95 5.00 '

set the latches. To 400 Khz operation. TTL compatible, MMS2030 Eraceable PROM 19.95 MAN -5 .27 Green 1.50 4.00
With instruction sheets and diagram on ''how -to -build 4.50 12.00
.

MM52020 Eraceable PROM 19.95 MAN -6 .6 Red

a d1/2 digit DVM ". Ideal w.,ith dr Litronix 1z single. .

MAN -64 .4 Red 3.50 9.00

1702A Eraceable PROM 19.95
S14a95 11/2" and dual digits. 16 -pin DIP, 1.00 2.50
. .

8223 Programmable ROM 2.95 MAN -7 .27 Red

MAN -8 .27 Yellow 1.50 4.00

Here is what
Poly Paks is Fabulous p za For the first time anywhere, Poly Pak
merchandisers introduce new war
in buying the economical way. Raw
stock from the "berro! ". Remember
ALL ABOVE BY

Typa
SLA -1
SLA -I
Slew Color
.33 Red
.33 Green
MONSANTO

Sale 3 for
51.95 SS.00
1.95 5.00
Famous for... T
They're back

tiBARRE1 sALF
the "good one days ,33 Yellow 1.95 5.00
again. The same way m handisert SLA1
throughout the United a Statea buy SLA -3 .7 Green 4.95 12.00
oir as 75 for various tactari.s ... their SLA -3 .7 Yellow 4.95 12.00
r IC s ir tress.
run n barreis. Poly Pak has done
the acme. Therefore you are getting
707 .33 Red 1.95 5.00
1.95 5.00
Marked 14 and/ i h Ifi
with 704A .33 Red
m0 dips, y lude gatee, the same type of meterial as the 701C .33 Red 1.50 3.00
flops. count- RE-TESTERS DO!
FND -70 .25 Red 1.50 3.00 SLA 3
era. Who known
s 75 for
A- Common Cathode, others Common Anode
B -With bubble magnifier
AMPS. $1.98 Your c ojee
LINEAR OP
709'., 741'.,
25 BARRELS PURCHASED FOR THIS SALE! of anY kit C-Plus or Minus 1
May Include
703's, 660 serie.. 666 In- BUY 'EM FROM THE "BARREL" AND SAVE!
eludes arked
marked. DIPS
and un-
LITRONIX "JUMBO'S"
NIT: Singles size: 1 x 3/4 x 5 /18
11011
SWITCNINO DIODES
rtaa
11/741 -® -100 for
$1.98
" " RECTIa cs 1ltp sass. TemC . 40 for
$1.98 30 for $1.98
aDuals R.: .8 x .9 x .29
100 for $1.98I'-"
May in-
41)ADRACS
All the famous plsetic pow- Raw fallout tock, arked
7- Segment. 25 -mlis per wgment
you never saw this before. 1154000 eriee
and unmarked stocky.. Bah- Type Sie. Color Sala 3 for
er tab type. Raw factory
Imagine famous switching
diodes at these prices!
elude 26. s 60. 100, 200,
400. 600. 800 .nd1000v etockl All the 10 amp type.. cock. Leach, etc. All types, I j 721D .5 Red $5.95 $13.00
727E .5 Red 5,95 15.00
VOLUME CONTROL
T fl SUBMINI eT4
TRANSFORMERS seas. Maca
eiT to
RUMS
NIT rtO
-Rt OISTt RS 746F .6 Red 3.95 11.00
40 for $1.98 747 .6 Red 3.93 11.00
40 for $1.98 40 for 51.98 30 for S1.98
Singles, duale, variety Amacing, Includes 466kce, 28 to 40 pin devices, D -Plus or Minus 1 plus a digit (11/ digits)
values, styles, big ones
of
antenna, who knows? All clod [,'Des, east
and voltasse.
am ákd, internal factory E-Dual digits
amall ones. om traneiator radio man- cresce numbers, eto F-Plus Minus 1

Tell RIT rte TEST 'EM

POWER TAe i s s 40 for 40 for rows ,g."" RESISTOP N[TWORNS PRECISION RESISTORS
Terms: :,.IAp -t:t u e Rated: net :t0
ISTORS $1.98 $1.98 sISTORS 40 for $1.98 200 for 51.98 YOURSELF hone Or 6 Del li'urvii M sen. f

/r
Marked and unmarked 1/ AND SAVE! Retail: 16-1n Del Carmine D.' tit.. Wakefield. Macs.
Mass.
NPN, plsetic 10220 type. PNP, Dl antic u'0220 type Sc Corning Glass. ,
tuft Water Street, C.O.D.'S MAY HE PIIONE[I
1/2.2 watt..
Aeeorted 2N numbers,
Mosrn
NIT t5
TRARSISroRs
Aeeorted 214

DISC CA
bers.

Np I TORS
pin dip pales.

LINEAR
RIT :IT
140 DIPS
KIT ra
.R CTIFIER MIY
Every kit Li 20c CATALOG On Fiber Optics,
MINIMUM ORDER 54.00 -
Semi's, Parts

loo for $1.98

POLY PAKS
100 for $1.98 carries
30 for 51.98 100 for $1.98 Subminiature,DO7'e, rnoney bank
All 4 leaders TO -18 case, Marked and unmarked.
a in-
includea UHF trenei.tors Marked and unmarked. Red ternal nu bers of fac- eludes asst. end guarantee.
tool case type asid. values. ory stuck, rectifiers. It's m zed s P.O. BOX 840E, LYNNFIELD,MASS.

CIRCLE NO. 43 ON FREE INFORMATION CARD

SEPTEMBER 1975 105

www.americanradiohistory.com
 OLD RADIO SHOWS, Over 10,000 hours (many rare) Latest
supplement $1.00 (refundable) Free reel coupon. Hart, 1329
MUSICAL INSTRUMENTS HOME ENTERTAINMENT FILMS George Washington, Richland, Washington 99352.
1930 -1962 Radio Programs. Reels, $1.00 Hour! Cassettes,
UP TO 60% DISCOUNT. Name brand instruments catalog. READ THIS AD AND SAVE MONEY! Apollo XV (The Rover $1.00 Show!... Mammoth Catalog, $1.25. AM Treasures,
Freeport Music, 455N Route 110, Melville, N.Y. 11746. Expedition on the Moon) -200' reels, Super 8, B& W, $5.95 Box 192PE, Babylon, N.Y. 11702.
WHOLESALE! Professional Guitars, PA Systems, Altec each PPD (limited quantity). 1972 Super Bowl (Cowboys vs. OLD RADIO SHOWS ON CASSETTES. $1.50 per show.
Speakers, 240W RMS Amplifiers. Free Catalog, Carvin, Dolphins), your choice Super or Standard 8, B &W, $5.95 Catalog 25 cents. Radio Classics, Box 804 A, Mattituck,
Escondido, Calif. 92028. each PPD. 1970 World Series, Super 8, B &W, $5.95 each N.Y. 11952.
PPD. Offer expires September 15, 1975. Save $3.00 on
FREE CATALOG! 30% ro 50% discount. Any model: guitar, STELLAVOX SP -7 Stereo Tape Recorder with 7 -1/2 and 15
every print you buy. 1975 Columbia, Castle & Sport lite film
amp, drum, banjo, dobro! Write: Warehouse, PE -3, Box i.p.s. head assemblies and all accessories in first class
catalogs, 30 cents each (coins or stamps). SPORTLITE, condition $1,500. Zorning, Ansonia Road, Woodbridge, CT
11449, Ft. Worth, TX 76109.
Elect. Dept. -9, Box 24 -500, Speedway., Indiana 46224. 06525.
FREE STEREO Catalog. Amplifiers, Receivers, turntables,
EMPLOYMENT OPPORTUNITIES
TAPE AND RECORDERS speakers, patchcords, cartridges. Audio Out, Box 4299,
Biloxi, Miss. 39531.
ELECTRONICS/AVIONICS EMPLOYMENT OPPORTUN- RECORDS -TAPES! Discounts to 73 %; all labels; no pur-
RENT 4 -Track open reel tapes major labels -3,000 -all
ITIES. Report on jobs now open. Details FREE. Aviation
Employment Information Service, Box 240E, Northport, different -
free brochure. Stereo-Parti, 55 St. James Drive,
Santa Rosa, Ca. 95401.
chase obligations; newsletter; discount dividend certi-
ficates; 100% guarantees. Free details. Discount Music
New York 11768. Club, 650 Main St., Dept 5 -95, New Rochelle, New York,
FOREIGN CIVILIAN JOBS. Information: Foreign assign- MEMOREX CASSETTE BONANZA. C90MRX2 pieces, -6 N.Y. 10801.
ments, American companies, All occupations. Indicate $3.29 each; 12 pieces, $2.39 each; over 12 pieces, $1.99
type work or degree. CMA: Publications, P.O. Box 10412, each. M &K Electronics Corp., 135 -33 Northern Blvd., INVENTIONS WANTED
Dept. F, Birmingham, Alabama 35201. Flushing, N.Y. 1,354.
INVENTORS: Protect your ideas! Free "Recommended
Procedure ". Washington Inventors Service, 422T
SEPTEMBER CALCULATOR CHIPS
Washington Building, Washington, D.C. 20005.
FREE PAMPHLET: "Tips on Safeguarding Your Invention."

SPECIALS Quality Cosmetic Seconds

41
CT5001 $1.79 ea. S .99
Write: United States Inventors Service Company, 708 -T
C15002 149 ea. .99 Carry Building, Washington, D.C. 20005.
SCHOOL TIME SPECIAL CT5005 2.99 ea. 1.49

POCKET CALCULATOR KIT MM5738 8 digit multiplexed -

five function
- -
5 function plus constant
addressable memory with
individual recall- 8 digit
- chain operation
decimal -
2 key memory
independent constant
floating

interfaces with led with only digit driver

-- Inventors Wanted
- -
9 V bats. oper. 24 pin 53.95 RECOGNITION, FINANCIAL REWARD,
display plus overflow
battery saver uses standard
- 9 DIGIT LED DISPLAY - FNA37 OR CREDIT for "inventing it first"
Send for FREE
INVENTORS KIT
or rechargeable batteries all
á On multiplexed substrate, comm. ca- may be yours! We'll develop your Includes Viral Infor-

assemble form
included
-
necessary parts in ready to
instructions
thode compatable with all 8 digit
calculator chips, 7 segment right hand idea, introduce it to industry,
mation on Protection,
Development, Marketing
of your Invention
CALC KIT
ASSEMBLED
$10.95
1 1.95
decimal, red with clear magnifying lens,
.12" character, 1 to 4 MA, 1.8 V typ 29:' x
3/4" x /"s" high $2.95
publicize it, negotiate fdr Cash
Sale or Royalty Licensing.
. Important "Invention
Record Form"
I
SET OF ALKALINE BATT. 2.00 3

Directory of S00 Cor-

TTL LINEAR MEMORIES RAYMOND LEE ORGANIZATION porations Seeking
MM1101 $1.39
7400
230 Park Ave. No., New York, NY 10017 New Products
S .13 3407 5V TO -220 $1.25 MM1103 1.49
7404 .15 340T 15V TO -220 1.25 MM5203 12.95
Please rush FREE INVENTORS KIT A-139
7408 .15 301N MINI DIP .15 MM5261 1.95
7410 .13 307H TO -5 .15 MM5262 3.95
I Name

TTL 7491
7492
.97
.71
re-5% OFF ON ORDERS OVER
10% OFF ON
$50.00
ORDERS OVER $100.00
rMEMORIES Address

7400 s .14 7493 .60 15 % OFF ON ORDERS OVER $250.000 1101 256 bit RAM MOS s 1.50
City State Zip
7401 .16 7494 .94 1103 1024 bit RAM MOS 3.95
7402 .15 7495 .79 2102 1024 bit slack RAM 5.55
7403
7404
.16
.19
7496
74100
.79
1.30
LINEAR CIRCUITS 5203
5260
2048 bit UV eras PROM
1024 bit RAM
17.95
2.49
7405 .19 74105 .44
300
307
Pos V Reg (super 723)
Op AMP (super 741)
TO -5
mDIP
S .71
.26
5261 1024 bit RAM 2.69 BUSINESS OPPORTUNITIES
7406 .35 74107 .40 5262 2048 bit RAM 5.95
308 Micro Pwr Op Amp mDIP .89 7489 64 bit ROM TTL 2.48
7407 .35 74121 .42
309K SV lA regulator TO-3 1.35 IMADE $40,000.00 Year by Mailorderl Helped others make
7408 .18 74122 .45 8223 Programmable ROM 3.69
7409 .19 74123 .85
310 V Follower Op Amp mDIP 1.07 256 bit RAM tri -slate 5.904 money! Free Proof. Torrey, Box 318 -NN, Ypsilanti,
311 Hi pert V Comp wDIP .95
7410 .16 74125 .54 Hi Speed Dual Comp
Michigan 48197. ,

319 DIP 1.13

7411 .25 74126 .63
320 Neg Reg 5.2, 12, 15 TO-3 1.04 FREE CATALOGS. Repair air conditioning, refrigeration.
7413
7416
.55
.35
74141
74145
1.04
1.04
324 Quad Op Amp DIP 1.52 CALCULATOR & Tools, supplies, full instructions. Doolin, 2016 Canton,
339 Quad Comparator DIP 1.58
7417
7420
.35
.16
74150
74151
.97
.79
340K Pos. V reg. (SV, 6V, 8V, CLOCK CHIPS Dallas, Texas 75201.
7422 .26 74153 .99
12V, 15V, 18V, 24V) TO -3 1.69 5001 12 DIG 4 fond li, dec $145 MAILORDER MILLIONAIRE helps beginners make $500
340T Pos. V reg. (SV, 6V, 8V, 5002 Same as 5001 esc blry pwr 195
7423 .29 74154 1.25
12V, 15V, 18V, 2401 TO -220 1.49 5005 12 DIG 4 Iund w /mem 4.95 weekly. Free report reveals secret plan! Executive (1K9),
7425 .27 74155 1.07
7426 .26 74156 1.07
370 AGC /Squelch AMPL DIP .71 MM5725 8 DIG 4 fund chain & dec 1.98 333 North Michigan, Chicago 60601.
372 AF -IF Strip detector DIP 2.93 MM5736 18 pin 6 DIG 4 fund 4.45
7427 .29 74157 .99
373 AM /FM /SS8 Strip DIP .53 MM5738 8 DIG 5 fund K & mem 5.35 PIANO TUNING LEARNED QUICKLY AT HOME! Musical
7430 .20 74158 1.79
7432 .23 74160 1.39
376 Pos. V. Reg mDIP 2.42 MM5739 9 DIG 4 fund Ibtry sur) 5.35 knowledge unnecessary. Free Information. Empire
380 2w Audio Amp DIP 1.13 MM5311 28 pin BCD 6 dig mur 4.45
7437 .35 74161 1.25 380-8 .6w Audio Amp wDIP 1.52
School, Box 450327, Miami 33145.
7438
MM5312 24 pin pps BCD 4 dig mm
1 3.95
.35 74162 1.49 Lo Noise Dual preamp
7440 .17 74163 1.39
381 DIP 1.52 MM5313 28 pin 1 pps BCD 6 dig mux 4.45 $200.00 DAILY In Your Mailbox! Your opportunity to do
550 Prec V Reg DIP .89 MM5314 24 pin 6 dig mux 4.45
7441 .98 74164 1.59 555 Timer mDIP .89
what mail-order experts do. Free details. Associates, Box
7442
MM5316 40 pin alarm 4 dig 5.39
.77 74165 1.59 556A Dual 555 Timer DIP 1.49 CT7001 28 pin 6 DIG alarm, date 6.95 136 -J, Holland, Michigan 49423.
7443 .87 74166 1.49 Phase Locked Loop
560 DIP 2.48
7444 .87 74170 2.30 562 Phase Locked Loop DIP 2.48
FREE BOOK "2042 unique proven enterprises." Work
7445 .89 74173 1.49 565 Phase Locked Loop DIP 2.38 home! Hayling -B, Carlsbad, CA 92008.
7446
7447
.93
.89
74174
74175
1.62
1.39
566
567
Function Gen
Tone Decoder
mDIP
mDIP
2.25
2.66
rLED'S ELECTRONIC Assemby Business. Big profits. Start home,
7448 1.04 74176
7450 .17 74177
.89 709 Operational AMPL DIP .26 MV10B Red TO 18 S .22 spare time. Investment, knowledge, experience unneces-
.O4 710 Hi Speed Voll Comp DIP M550 Axial leads .18
7451 .17 74180 .90
.35
MV5020 Jumbo Vis. Red (Red Dome) .22 sary. Free illustrated literature. Barta, Box 248CW, Walnut
723 V Reg DIP .62
7453 .17 74181 2.98 739 Dual Hi Pert Op Amp DIP 1.07 Jumbo Vis. Red (Clear Dome) .22 Creek, Calif. 94597.
7454 .17 74182 .79 741 Comp Op Amp mDIP .32 ME4 Infra red dill. dome .54
7460 .17 74184 2.29 747 Dual 741 Op Amp DIP .71 MANI Red 7 reg..270" 2.19
P -2
7464 .35 74185 2.29 MAN2 Red alpha num .32" 4.39

Walt
748 Freq Adj 741 mDIP .35
7465 .35 74187 5.95 MANO Red 7 seq..190" 1.95
1304 FM Mulps Stereo Demod DIP
7470 .30 74190 1.35 1307 FM Mulpx Stereo Demod DIP
1.07
.74 MANS Green 7 reg..270" 3.45 Citizens Band
7472 .30 74191 1.35 MANG .6" high solid seq. 4.25
1458 Dual Comp Op Amp mDIP .62
7473 .35 74192 1.25 MAN7 Red seq..270" 1.19
7474 .35 74193 1.19
1800 Stereo multiplexer DIP 2.48
MANO
7

Yellow 7 seq..270" 3.45

DEALER -DISTRIBUTORS
3900 Quad Amplifier DIP .35
7475 .57 74194 1.25 7524 Core Mem Sense AMPL DIP .71 MANM .4" high solid seq. 2.95 Send this ad with Letterhead to
7476 .39 74195 .89 MAN66 .6" high spared seq. 3.75
7534 Core Mem Sense Amp DIP .71
7483 .79 74196 1.25
8864 9 DIG Led Cath Drvr DIP 2.25 MCT2 Opto -iso transistor I PAL ELECTRONICS CO.
7485 1.10 74197 .89
75150 Dual Line Driver DIP 1.95
7486 .40 74198 1.79 75451 Dual Perepheral Driver mDIP .35 2962 W. WELDON - PHOENIX, ARIZ. 85017
7489 2.48 74199 1.79 Dual Peripheral Driver
75452 mDIP .35
7490 74200 5.90
.59 75453
75491
13511 Dual Periph. Driver mDIP
Quad Sect Driver for LED DIP
.35
71
rCMOS 4015A
4016A
1.49
.56
4049A
4050A
.59
.59
GET RICH with Secret Law that smashes debts and brings
Ann 5'.n 75441 Hex Digit Driver DIP 80 4000A S .26 40176 1.19 4066A .89
4001A .25 4020A 1.49 4068A .44 you $500 to $5 Million cash. Free report! Credit 41(9, 333
4002A .25 40216 1.39 4069A .44 North Michigan, Chicago 60601.
Satisfaction guaranteed. Shipment will be made via firs) class mail within 3 days from receipt of 4006A 1.35 4022A 1.10 4071A .26
order. Add 5.50 to cover shipping and handling for orders under 025.00. Minimum order 55.00. 40076 .26 4023A .25 4072A .35 BEAUTIFUL WAY TO MAKE MONEY selling instant
California resident, add sale, tas. 40086 1.79 4024A .89 4073A .39 fountains. Shipped with pools, fill with water, plug in and
40096 .57 4025A .25 4075A .39
enjoy. ROMAN FOUNTAINS, INC., Box 10288 -Z, Albu-
INTERNATIONAL ELECTRONICS UNLIMITED 4010A .54 4027A .59 4078A .39
querque, N.M. 87114,
40116 .29 40286 .98 40816 .26
P.O. BOX 1708/ MONTEREY, CA. 93940 USA 40126 .25 40306 .44 408M .35
FM RADIO STATION. Start your own. Fantastic income.
PHONE (408) 659 -3171 40134 .45 4035A 1.27 4528A 1.60
6.0_014A 1.49 40424 1.47 4585A Frequencies still available. Complete information $3.00.
Concept, Box 106, Lawrence, N.Y. 11559.

CIRCLE NO. 25 ON FREE INFORMATION CARO

106 POPULAR ELECTRONICS

www.americanradiohistory.com
tiff
SN7400N
SN74015
.16
.16
7400N
SN74515
SN7453N .27
TTL
27 SN74151N
SN741535
4011
125
35
DmI
0
Each
- Latches
Board Oscillator
-
Man7 Displays
DIGITAL COUNTER UNIT TTL Logic Probe Kit
Detects TTL levels,
pulses, with man 3 readout
trap/
-_.

IC'S IEKL\ KITS,

FUNCTION GENERATOR KIT
4
S574025 .21 SN7454N 41 SN74154f4 1 25
10000 Counter $9.95 per kit
S574035 .16 S514594 .25 5514155N 1.21
SN7404N .21 SN7460N .12 SN74156N 1.30 Complete with Board
SN1405N .24 S574705 45 SN74151N 1.30 DVM Chip Set Siliconix
257406N 45 SN7472N .39 2574160N 1.75 DIGITAL VOLTMETER KIT LO I IO Digital AID Processor 16.00
$28.00 Sat
SN7407N 45 SN7473N 45 SN74161N 45 Ln1I1 Analog A/O Processor 13.00
S5741635 1.65
1

0 -2 Volt, Auto Polarity 354 digits (MAN7)

SN7408N .25 SN7474N 45
DVM MOS - LSI Design leawres sine,
SN7409N 25 S574755 .80 5574164N I.65
DM889ON triangle and
5574105 20 SN7476N 47 SN74165N 1.65
SN7411N .30 SN74805 .50 SN74166N 1.70 Complete Horiz.Nert. Divider square wale;
SN7412N 42 S0174825 1.75 5574167N 5.50 $39.95 Chain for T.V. Type, Appl. 1.95 Each T HO 0.5% YIP..
SN7413N .85 SN74835
1
1.15 SN74170N 1.00 AM /FM capability
SN7414N
SN7416N
SN7417N
.43
.43
70 SN7485N
SN7486N
SN7488N 3.50
45
SN74172N
SN74173N
SN74174N
18.00
170
1.95
4' POWER SUPPLY CORDS .... 5
POCKET CALCULATOR KIT
function plus constant
addreaabH memory with
-
SN7418N .25 S574895 300 S5141755 1.95 Black individual recall 8 digit -
SN7420N ,21 SN7490N .59 S5741765 90 Oa .594 ea. display plus overflow - battery
S574215 .39 SN7491N 1.20 SN74177N .90 seaer -
uses standard or
SN7423N .37 S574925 12 SN74180N I.05
SN74255 .43 SN74935 .82 SN741815 3.55
rechargeable batteries- all
XR2206KA $19.95
S574265 .31 SN74945 91 SN74182N .95 THUMBWHEEL SWITCHES eaeVary

mble form netructions

pans In

-
ready to
Includes monolithic function generator IC, PC board, and assembly
S574275 .37 S574955 11 SN74184N 2.30 included. 3" a 514" ... ...... $17.50 each instruction manual.
0574295 42 6574965 91 0574185N 2.20 (.4- 111 ui 3.:öenrei OPTIONS -
$29.95
1574305
05743218
2574375
.26
.31
47
SN74100N
SN74107N
08741215
1.25
49
.55
SN74187N
35741905
SN74191N
6.00
.50
.50
i 3
2!
li
EfL:'

IIF
.0
115VAC Transformer
6 each "N" Alkaline Batteries
4.95 each
2 5010
XR- 2206KB
Same as
for PC board.
XRQ206KA above and =Was external components

057438N .40 0574122N .49 S5741925 50 .394" DIAM. TRIMMER

40 TIMERS
5574394 .25 S5741235 1.05 S5741935
0574405 05741255 .60 S5741945 .45 XR -555CP Monolithic Timm $ 1.10
057441N 1.10
.21
SN74126N 81 S5741955 .00
an emu XR320P Precision Timer 1.55
0574425 718 SN74132N 3.00 SN741965 .25 XR-5560P Dua1555 Timer 1.85
21974435 105 SN741418 1.15 SN74197N 00 XR-2556CP Dual Timing Circuit 3.20
0574445 1.10 SN74142N 6.50 05747985 .25 11011111..0
1-1 OR240CP Programmable Counlet/Timer 4.80
SN74455 1.10 SN74143N 7,00 SN74199N .25 Model
S574465 1.15 58747448 7.00 S5742008 .00
mn b PHASE LOCKED LOOPS
01874475 .89 S14741455 1.15 S14742515 .50 XR -210 FSK Demodulator 5.20
04 -215
0574488
S874508
.99
.26
S8741488
SN 14150N
08742845
290
55742855
1 II
00
.00 : 1/16 VECTOR BOARD OR-567CP
High Frequency PLL
Tone Decoder (mini DIP)
6.60
1.95
20% Discount Inr 100 Combined 7400's XR 567CT Tone Decoder (T0-5) 1,70
STEREO DECODERS
C04000
C04001
.29
.29 CMOS 740105
74C20N
6S
65 XR1310P PLL Stereo Decoder 3.20
C04002 .29 C74070 65 14C30N 65 X R- 1310EP PLL Stereo Decoder 120
C04006
004007
CO4009
2.50
.29
.59
004035
C04040
C04042
1.85
2.45
1.90
740425
74C73N
74074
2.15
1.50
115
°PROIOBOAID.100 X R1800P PLL Stereo Decoder
WAVEFORM GENERATORS
3.20

34010 004044 1.50 74C90N 3.00 Here a IoW COS?,Ilog 10 IC rapacity X R-205 Waveform Generator 8.40
C .59
c04011 .29 C04046 2.51 74C95N 2 00 breadboardkit with ail the quality of XR- 2206CP Monolithic Function Generator 5.50
C04012 .29 C04047 2.75 7401015 125 OT Sockets and the best of she Proto WALL or T.V. DIGITAL CLOCK OR- 2207CP Voltage -Controlled Oscillator 3.85
C04013 .53 C04049 .79 74C151 290 Board a complete down to the 12 or 24 Hour OTHER EXAR IC'S
C04016 .69 C04050 .79 140154 3.00 Iasi nut, bolt and screw. Includes
25' VIEWING DISTANCE
298 07355 107358 XR- 1468CN Dual 9 15V Tracking Regulator 3.85
C04017 1.35 C04051 74C157 215 2 Sockets. Bus Strip:
Walnut Case.6" a 3" x 1"
C04079 C04053 2.98 14C160 3.25 2 5Way binding posts; 4 rubber feet. OR -1488N Quad Line Driver 5.80
.69 Hr. & Min. 6" High
C04020 1.69 C04060 3.25 740I61 3.25 screws. nuts, bolts; and easy assembly XR-1489AN Quad Line Receiver 4.80
004022
004023
C04024
1.25
.29
1.50
004066
C04069
004071
1.75
.45
.45
74CI63
740764
74C113
3.00
3.25
2.60
COMPLETE KIT $1995 Seconds -3" High
KIT All Comp. & Casa
Wont
-

& Assembled 115 Vac

03195
$44.95
SR -2208CP Operational Multiplier
XR -2211 CP FSK Demodulator/Tone Decoder
5.20
6.70,
C04081 .45 X0 2261 Monolithic Proportional Servo IC System
C04025 .34 74C 193 2 75
w/4 ea. Driver Transistor 3.79
C04027
004028
.85
1.65
14C008
74CO2N
.39
55
74C195
80C91
2.75
1.50
DISPLAY LEDS DISCRETE LEDS
Common Cathode
*Special Requested Items*
CA Common Anode CC
C04029 2.90 74C04N 75
MAN 1
Com. Ano. .270 $1.95 MV IC Rea 5/51.00
LMIOOH 15.00 LM1310N 2.95 MAN 2 5x7 Matrix .300 4.25 MV 50 Per 6/S1.00 a o4,1710 V Oo S595 N4T97 S3.00 2531 Sil 115
LM106H 2.50 144135114 I 65 MAN 3 Com. Cath. .125 .95 MV 5024 Red 5/Sl SO
Bc4195 15r clan Rae Me 225 5.95
3 25 6261
LM171H 3.75 LM3735 325 LM1414N 1.75 MAN 4 Com. Cath. .187 1.95 MV 5024 Green 4/51 00 MC1141 Hien Sias OS Amp 4.00 2511 1I 00 8261 215
LM212H 7.00 1M3775 4.00 1M14580 65 MAN 7 Com. Ano. .30 1.50 MV 5024 Yellow 4 S00 14404111 4 50 151A 7 00 s 1.15
CA3130 lunar CMOS O0Amp149 2524 250 6826 3.00
LM300H 80 153808 1.39 LM1496N 95 DL33 Com. Cath. .125 1.95 MV 5024 Orange 4 S1 00
40410 3* ANA 600
175 1525 8860 1 35
LM301H 371.00 0M38005 1.05 LM1556V 1.85 01545 Com. Ano. .625 2.50 0673 3. NAN 5 2527 5.00 91 5 00
LM30ICN 3/190 LM381N 1.79 1M21115 95
-
1

1913025 .75 LM3825 1.79 LM29015 295 IC SOLDERTAIL LOW PROFILE (TIN) SOCKETS
07/130411 1.00 NE501K 800 LM3065N .69 124 2549 50100 124 2549 50100 IZ,na,/ DIODES I RatdielI
LM305H .95 NE510A 6.00 0539008 .55 TYPE VOLTS W PRICE TYPE VOLTS W PRICE
8 pin 2.19 .18 .17 24 pin S 68 .62 56
LM307CN .35 NE531H 3.00 LM39055 60 N746 3.3 40011 4/1.00 54003 200 PIV 1 AMP 10
14 pin .23 .22 21 28 pm 89 81 .73
LM308H 1.00 5E5367 6.00 1M555601 1,85 5751A 5.1 400m 4/1.00 54004 400PIV I AMP 10
l6 pm .27 .26 24 36 pin 110 99 90
LM308CN 1.00 5E5401 900 1105558V 1.00 14752 53 400m 4/1.00 53600 50 200m 6 /1.00
18 pin 46 41 .37 40 pin I.25 1.13 93
LM309H 1.10 5E5505 .79 1.575255 90 N753 6.2 40011 4/1.00 N4148 75 10m 15/1.00
22 Pm 65 59 53
LM309K 1.25 NE553 2.50 LM75285 2.20 N754 6.8 400m 4/1.00 54154 35 10m 12/1.00
LM310CN 1.15 NE555V 75 1.575348 2.20 SOLDERTAIL STANDARD (TIN) N9658 15 400m 4 /1.00 54734 5.6 I. .28
LM3I1H .90 NE565H 1.25 LM75355 1.25 14
pm $30 28 26 28 pin 5 99 90 81 55232 5.6 500m .28 54735 6.2 1w 28
LM31IN 90 5E5655 1.95 80389 495 16 pm 33 31 29 36 pm 1.39 1.26 1.15 55234 6.2 500m .28 N4736 6.8 I. 28
LM318CN I 50 NE566CN 1.95 LM75450 49 18 pin 42 39 37 40 pin 1.59 I 45 1.30 55235 6.8 500m 28 N0738 8.2 I. 28
LM3195 1.30 5E56711 1.25 75451CN 39 24 pm 59 .54 49 N5236 7.5 500m 28 54742 12 lw .28
LM3190 9.00 NE567V 1.95 75452CN 39
SOLDERTAIL STANDARD (GOLD)
5456 25 40m 6 /1.00 N4744 15 I. 28

15320K 5 135 LM703C5 45 75453CN 39 5458 150 Inn 6 /1.00 51163 50PIV 35 AMP I 60
8 pin 5.30 17 24 24 pin 8 70 63 57
51184 100 PIV 1.70
LM320K9.2 1.35 LM709H .29 754540 el 39 5485A 180 10m 5 /1.00 35 AMP
pin .35 32 29 28 pin 1.10 I 00 90
18320K12 7.35 LM7095 .29 75491CN 79
14
54001 50PIV 1 AMP 09 NIIB6 200 Ply 35 AMP 180
16 pin 38 75 32 36 pin 1.55 I 40 1 26
LM320K15 I.35 LM710N .79 75192CN .89 54002100PIV I AMP 10 N1198 400 Ply 35 AMP 3.00
18 pin 52 41 43 40 pin 1.75 1 59 I 45
LM323K9 14.00 LM7115 .39 75494CN 89
LM3245 1.80 1917235 .55 RCA LINEAR WIRE WRAP SOCKETS (GOLD) LEVEL 3 TRANSISTORS
LM3395 1.70 LM723H 55 CA3013 1.70 10 pin S 45 41 37 24 pm 51.05 95 85
LM340K-5 1.95 LM7335 1.00 CA3023 2.15 14 pin 46 42 .38 28 pm 1 40 1 25 1.10 MPS A05 5751 253905 4;51
45 130 25918 M' .25 2529064 4/S1 253900 4 /SI
LM340K 12 1.95 11017395 1.29 CA3W5 2.25 16 pin 55 50 45 36 pin 1.59 1

252219A I 3 /SI 2N2907Á 5/S1 P54249 4 /SI

LM340K-15 1.95 LM74ICH 3/1.00 CA3039 1.35 18 mn 15 68 62 40 pin 75 1 55 140
P54250
1

252227 III' 4/51 253053 2/SI 4/$1

18340K24 115 LM74 ION 3/1.00 CA3046 1.15
2522224 5,/1 253055 95 254409 5 /SI
LM3401n-5 1.75 14741-145 39 CA3059 2.46 252369 5/SI 253725A 2/S7 255129 . 19
LM340TO.6 1.75 1M7475 .79 CA3060 2.80 50 PCS. RESISTOR ASSORTMENTS $1.75 PER ASST. 2523694 4 /S1 283903 5/S1 255139 19
LM340TO.12I.75 LM7475 .79 CA3080 85 252484 4'91 253904 4/S1 C106819CR 2/51

,-
1M340T0.151.75 15174811 .39 CA3083 1.60 10 OHM- OHM 15 OHM. 18 OHM 22 OHM
12

15134070 241.75 1M7485 .39 CA3086 .59 ASST. 1 5 ea: 27 OHM. 33 OHM- 39 OHM. 47 OHM 56 OHM 1/4 WATT 5% ' 50 PCS.
LM3505 1.00 LM13O35 10 CA3089 CAPACITOR CORNER j____04
25 68 OHM- 82 OHM -100 OHM.120 OHM I50 OHM
1035105 .65 1M13045 1.19 CA3091
3

8.25 ASST. 2 5 ea: 180 OHM -220 OHM-270 OHM -330 OHM390 OHM 1/4 WATT 5 %= 50 PCS. fil 50 VOLT CERAMIC DISC CAPACITORS
1913705 115 19413055 I 40 003123 I 85 I.9 1049 50.100 19 1049 50 100
470 OHM.560 OHM.680 OHM 820 OHM 1K
16137011 1 15 LMI3OI5 VS CA3600 I.75 lops .05 04 03 001 05 04 .035
ASST. 3 5 ee: 2K 1.514 7.8K 2.2K 2.7K 1/4 WATT 5 %= 50 PCS. 035
1

22 el 05 .04 03 0017 05 .04

MICROPROCESSOR COMPONENTS 13K 3.9K 4.7K 5.6K 6.8K 47 pl 05 04 03 01 05 .04 035
ASST.0 5ea: 8.2K 10K 52K 15K 18K 1/4 WATT 5 %= 50 PCS. 100 PI 05 04 03 022 .06 05 .04
8008 CPU $29.95 8111 1024 RAM $12.95 220171 .05 14 .03 047 .06 .05 04
8080 CPU 149.95 1702A OK PROM 29.95 22K 27K 33K 39K 47K 470 pl 05 04 .035 I .12 .09 .075
7489 646 RAM 2.95 52032 214 PROM 19.95 ASST. 5 5 a.: 56K 68K 82K 100K 120K 1/4 WATT 5 %n 50 PCS.
100 VOLT MYLAR FILM CAPACITORS
8599 Tri -State 7489 3.50 8223 PROM 3.00 150K 180K 220K 270K 33014 l0 .022mf .13 .11 .08
.001mí .12 .01
1101 2568 RAM 2.25 2401 2K SR 9.95 ASST. 6 5 ea: 390K 470K 560K 680K 82054 1/4 WATT 5 %= 50 PCS. .0470 .21 .17 .13
3022 .12 .10 .07
2102 114 RAM 4.95 2533 1K SSR 11.85 .1mí .27 .23 .17
IM 12M 1.5M 1.8M 2.2M .0047mí .12 .10 .07
8101 1024 RAM 11.95 AY 3.1013 UART 7.95 .72 .07 .22mí .33 .27 .22
ASST. 7 5 ea: 2.7M 13e 19M 4 7M 96M I/4 WAIT 5%. 50 PCS. .01mí .10
1010 1K NMOS Retains data w/o Power
RAM 29.95 220% DIPPED TANTALUMS MOL ID/ CAPACITORS
2107 4K RAM 45055 Access Ome -22 pin DIP 1935 35V 28
I 23 17 1.5 35V .30 .26 21
Vector General Purpose Logic CARO Board 1495 SN 74130 7401 1402 7403 7404 35V .28
15 .23 17 2.2 25V 31 27 .22
ASST a 3 e ì6i,TTL S5.95 ASST
'Very High Noise Immunity Holds 12 ea. 14 pin GIPS PRIME SN1410 7430 7438 7440 7472 35V 28
22 23 .17 33 25V 31 27 22

44 pin Edge Connection 35V 28

33 23 17 4 25V 32 .28 23
INTEGRATED 0,19 lea
SN1441
SN74a5
7490
74175
74491
74180
74100
74191
74101
14193
MSI/7T1 59 95 ASST 47 35V .28 23 17 6.0
7

25V .36 .31 25

THE KILOBYTE RAM CARD Per Oil 69.95 CIRCUIT C04001 4002 4011 4012 4013
.68 35V .28 .23 II 10 25V 40 .35 .29
IO 1a. CMOS 09 95 ASST 0 35V 20 23 17 15 25V 63 50 .40
'Complete IKx8 Memory High Noia Immunity Components ASSORTMENTS ASST C04016 4017 419 4023 4030 1

Single 54 supply 50055 Access Time &Kit includes sockets, ICI & 1a LM30It 3018 317 309íc MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS
i
74, SIO 95 ASST Racier Lead
Amer Lead
Board
47 50 15 .13 10 .47 25 15 13 10
50 16 .14 .11 47 50 16 .11 .11
FREE With each $75 order of Microprocessor components, Satisfaction Guaranteed. $5.00 Min. Order. U.S. Funds. 1

13 50 16 15 13 10
California Residents -Add 6% Sales Tax
15 13 10 1

$12.00
Value
get
compuar
one year subscription
PHR EA KS
to BYTE the megaaine for
FREE FREE FREE
Write for FREE 19755 Catalog Data Sheets .25e each - 47
10
25
25
16
15
14
13
12
10
I
I
25
50
16
I6
.14
.14
11
11

;rfN$S
10 50 16 14 12 4.7 IB 15 .13 10

1091 598000 3nn

SERIES8552 2 49
49
22
22
25
50
17
24
15
20
12
18
47
4.7
25
50
15
16
.13
11
10
11
8092 59 8223 8554 2
47 19 17 15 10 16 14 .12 09
25
8095 I 39 8230 2.59 8810 79 41 50 25 21 19 10 25 15 .13
8121 89 8263 7.00 8820 200 100 25 24 20 .18 10 50 16 14
8123 1 59 8267 4 00 8826 3 00 100 50 35 30 28 41 50 24 21 9
8130 2 19 8280 75 8830 259 220 25 12 28 25 100 16 19 15
24
8200 2.59 8281 85 8831 259
P.O. BOX 822, BELMONT, CA. 94002 220 50 45 41
29
38 TOO
100
25
50 35
20
.30
8

- (415) 592 -8097

8210 3 49 8288 115 8836 49 470 25 33 27
129 1000 16 55 50 45 220 16 23 17 6
8214 69 8520 8864 2.00
PHONE ORDERS
1

2200 16 70 62 55 470 25 37 28 6
8720 169 8551 165 8880 135
I
CIRCLE NO. 26 ON FREE INFORMATION CARD
SEPTEMBER 1975 107

www.americanradiohistory.com
 QUALITY ELECTRONIC COMPONENTS\
- SAME DAY SERVICE - INSTRUCTION
NEW DISCOUNT SCHEDULE
NEW KITS ! NEW KITS !

SAVES YOU EVEN MORE!

LEARN ELECTRONIC ORGAN SERVICING at home all
makes including transistor. Experimental kit- trouble- JAMES ELECTRONICS
1024 BIT STATIC MOS RAM shooting. Accredited NHSC, Free Booklet. NILES BRYANT P. 0. BOX 822 BELMONT. CALIFORNIA 94002

2102...
(415) 592.8097
SCHOOL, 3631 Stockton, Dept. A, Sacramento, Calif.
$3.50 95820.
DIGITAL VOLTMETER
INTEGRATED CIRCUITS - TTL, CMOS, LINEAR 8 MOS LEARN WHILE ASLEEP, Hypnotize! Strange catalog free.
Auto -suggestion, Box 24 -ZD, Olympia, Washington 98501.
7<53N 351851 28
.AE 5a 5.1
14015 24c 74545 22c 74156N 10214E. 45207E SI18
74035 24c 74605. .M5 71157N 40715..
51.56
S112 15MAF. 5100 DEGREE IN ELECTRONICS through correspondence. Free T
71051. 24c 14705. ... 315 7416M S'.. 55350E 9á This is a 3121 digit, 0,2 volt Digital Voltmeter,
74015. Nc 71135 .34c 74161X. SI '`
4017AE. ..51
47737E 215
18
NE5401 S2.04 catalog. Grantham, 2000 Stoner Avenue, Los Angeles, with a .5% full wale accuracy. It is baud
74055. .. 247 74715 ...
74065 M[ 74715. .
31c
31C
74162E
741635..
. SI 19
SI 19
40744E
40750E ..
46,
74
555537
5E5555
S1.81
f1.87
California 90025. >u the Slliconix LD110 L0111 DVM
sd
et. The voltmeter uses MANINI ,..dosed
74075
7409N
7101N
74c
242
74c
]a76N.
74108..
74805.
.

..
Slc
313
687
741745
711755
711755.
SI 20
5109
51.02
4026ÁE. ..51 77
/0212E .. 642
40290E .. SI 04
5E555V
M5560..
NF5600... 53.83
88c
eE5 INTENSIVE 5 week course for Broadcast Engineers. F.C.C. 111111110P I.3u high) to provide a h,ghly readable dis-
play. The unit requires the following supply
741p1 N5 74835.. .68c 711805 .. 77c I0294E SI 36 5E5618... 53.83 First Class license. Radio Engineering Incorporated, 61 N.
voltages: 12, -12, 5. The unit comes co
.

245 74835 711815. .. 5E5619... 53.83

74135 ... 24[ 74855 ..51
685
11 741935 ..
53.13
857
4030ÁE
4033AE 516I
507
5E5655 S1 45
Pineapple Ave., Sarasota, Florida 33577 and 2402 Tide- plate with all components to build the unit
74135. 2k 14969 pictured et the left that is a complete DVM
1165 51 .07 745095 .. f113
315 741915
741915
. S115
fl IS
40347E... 5J.34
40355E 36
5E56713..
NE5678 ..
SI
SI
38
34
water Trail, Fredericksburg, VA 22401.
74175 ..
51
less power supply
24, 74915 18 741935. 51.19 40175E SI .60 u5709C5.. 433

MIER!
74175 ... 14c 749151. 775 741935 51 11 40415E ... 90c u0710CA,. 373
74205 .. 24, 11931 585 741945 51 11 40135E ... 97c ,4711[5. 37c
74215
74255
.. 21c
65c
74935
74955
48c
Mc
741955...
702795.
fI.II
56c
40435E
18400E
.. 67c
675
u4713C0.
u5711CV...
405
535
$39.95 Per Kit
74265 345 71955 95c 10004E. 74c 40465E 51.35 u0747C5.,.7e4
74315 43, 74965 773 40815E 7<c 40595E 52c u57100/. .. 41c
74335.. ..53 741035 fl 14 1002.5E .. 155 10505E 525 3171558V... 515
PASS FCC EXAMS1 Memorize, study - -Tear
74375.
74305.
.210
. 210
741075
111115
53
kc
48065E..
40075E ..
51.50
747
40517E
40515E
SI 44
SI 44
1129
1.130 ..51.25
51.25
A, .,S" for FCC 1st end 2nd claw Radio. LOGIC PROBE
74405 . .. 217 741n5 accord SI 17 10534E. 5111 1131 ...51.30 Telephone Irene, Newly reread multiple
7415 _.31.11 711135 IS 10094E 645 40604E... 51 67 IM309A ..51.90
74431
.

61c 741255... Ac 48104E.. 744 40775E.. .917 I7A324A .51.28

droiw queerness end d.agrrne cover ell ores
74435 61c 741165 ... 390 40115E.... II0 40715E. 270 u470050. 11.25 Meld In FCC exams plus "self -Study Ability The Logic Probe is a unit which is for the
74445 61c 741315.... 73. 10125E ..14 40724E 267 .57806C1). 51.25 Tea." SILO peeped. Moneybaok Goerone . most part despensble in trouble shooing
71455 61c 741115. 91[ 40130E SN 10730E .. 264 u57909CU,51,25 logic families: TTL, DTL RTL CMOS. It
74175 IIc 40750E ..
74475 1)5
141105
)41505
51.16
51 .36
4011AE
.01504 .51
51 58
11 40815E ..
26e
767
u57813717. 51.25
4078152U 51.25
t OMMAND PRODUC 71ONS P.O. 80X 26348-P de' h power' t needs to operate erectly "ggrit- ---
off of the orcuit under test, drawing a scant
7449N. 855 741515....857 40164E ..5D 40825E
45pL5E...SLI6
..1M W781000.51.25 4E80 1404118187 47477754 SAN FRANCISCO, CALIF. 94126 It LW a MANS readout to
74515 225 141535... Pa 40175E... R.76 3A7821CU. 51.30 A
74515 n[ 711515... 51.34 .0187F 51 .44
.
45114E.. . f1 60 2103 ...
53.50 . d v f the follong
following states by these
SCORE high on F.C.C. Exams Over 300 questions and symbols IRN a (PULSES-P. The
SILICON TRANSISTORS answers. Covers 3rd, 2nd, 1st and even Radar. Third and
'.
1400O911
1

Probe can detect high frequency Pulses to

E81915 213 10/$2.00 IC/517.85 2N3640 215 10/12.00 1C/517.85 45 MHz. It can't be used at MOS levels or
EN930 16c 10/11.55 1C/S13,60 2153641 16c 10/51.55 10573.60 Second Test, $14.50; First Class Test, 515.00. All tests, circuit damage will result,
MP5930 70/51.55 1C/513.60 2N3643 10/11.55 1C/513.60
16c 16c $26.50. R,E.I., Inc., Box 806, Sarasota, Fla. 33577.
EN2722 16c 10/51.55 1C/513.60 MP53643,...165 10/11.55 1C/513.60
MP522720 .., 10/51.55 1C/113.60 253645 10/12.00 1C/117.85 UNIVERSITY DEGREES BY MAIL! Bachelors, Masters,
E623690....160
16c
10/51.55 1C/513.60 253646
215
215 10/52.00 1C/517.85 $9.95 Per Kit
MPS2369A,..16c 10/11.55 1C/113.60 253904 16c 10/51.55 1C/113.60 Ph.D's. Free revealing details. Counseling, Box 1162 -PE9,
MP52712.,.,163 10/51.55 1C/513.60 263906 165 10/11.55 1C/513.60
E152907 16c 10/51.55 1C/513.60 254124 16c 10/11.55 1C/513.60
Tustin, California 92680.
MP52907A,..165
2533914. 216
10/51.55
10/12.00
1C/513.60
IC/SI 7.85'
254126
2N4401
160
16c
10/11.55
10/51.55
1C/113.60
1C/513.60
SELF -STUDY CB RADIO REPAIR COURSE, THERE'S DIGITAL COUNTER
263392 160 10/11.55 1C/513.60 204403 165 10/51.55 1C/113.60 MONEY TO BE MADE REPAIRING CB RADIOS. This easy - This a 4 dig,. outer unit Which will
MPS3392....163 10/51.55 1C/513.60 265087 16c 10/51.55 5C/513.60 UP 0 5909 and than provide an over
2N3393 16c 10/11.55 1C/51160 265089 16c 10/11.55 1C/513.60 to -learn course can prepare you for a career in electronics flow tpulse. It is based around the Moetak
MP53393.... 16c 10/51.55 1C/113.60 1 255129 215 10/12.00 1C/117.85 enabling you to earn as much as $16.00 an hour in your MK5007 digital counter chip. The unit P.O.
2153394 16c 10/11.55 40/513.60 265133 21c 10/52.00 1C/577.85 forms the following functions, Count Input.
spare time. For more information write: CB RADIO REPAIR

I6
MP53394....16c 70/51.55 1C/513.60 265134 215 10/52.00 1C/517.85
MPS3395.,,, 16c 265137 1C/517.85 RESET, Latch, Overflow. The counter ope.
10/11.55 1C/113,60 215 10/52.00 COURSE, Dept. PE095, 531 N. Ann Arbor, Oklahoma City,
263563 21c 10/12.00 1C/517.85 255138 215 10/12.00 1C/517.85 ates up to 250 kHz, The counter Is en ideal
263565 21c 10/52A0 1C;517.85 265139 215 10/12.00 1C/117.85 Okla. 73127. to used e
a 14791.470, countar, wore

1(11 3.60 765210. 10/11.55 1C/513.60 urneba

be extra W needed would be
263638
163638

,,.16c
MP536380
16c 10/51.55
10/11.55
10/51.55
1C113.60
10113.60
265457..,..
MPE-102 .... 48c
16c
520 10/54.08
10/34.50
1C/544.20
1C/540.80
DRAFTING- Blueprint Reading (Mechanical, Electronic, divider chain
n
and pace. unir
5V, and -12V. The u
equires
MPS-A 13 . . . . 408 10/53,75 1C/534.00 Architectural). Home Courses $25.00. Send $2.00 first les- complete es shown on the left less power
son. Prior, Inc., 23 -09 169th Street, Whitestone, N.Y. 11357. SuPPN
ELECTROLYTIC CAPACITORS

lufd/50v
- Radial Load
8c 10/64c
-
A:IaI Lead
1C/S 5.41 10u651/500....
- 145 10/51.13
- 1C/5 9.56
UPDATE your electronics knowledge and add a FCC first
class license. Home study. Free catalog. Gann Tech., 5540
$29.95 Per Kit
2.2ufd/50v 8c 10/64c 1c/5 5,41 22ufd/16v.... 12c 10/98c 1C/S 8.31
Hollywood Blvd., Los Angeles, CA 90028.
3.3ufd/SOv Bc 10/64c 1C/1 5.41 22ufd/25v .... 13c 10/11.03 1C/5 8.74
4,72fd/25v 8c 10/64c 1C/S 5.47 33ufd/16v ,... 125 10/11.00 1C/1 8.48
FM BROADCAST STATION. Start your own. Learn how. ONE KILOBYTE RANDOM ACCESS MEMORY
1OUfd/25v Sc 10/67c 1C/S 5.66 33ufd/25v ... .14c 10/51.13 1C/i 9.56
10ufd/50v, 10c 10/770 1C/S 6.58 47ufd/16v .... 148 10/11.13 1C/S 9.56 Details free. Broadcaster, Box 5516AK, Walnut Creek, CA
220651/255 9c 101728 1C/S 6.09 47ufd/25v .... l7c 10/1732 1C/S11.22
94596.
22ufd/50v.,, 10/11.00 123 IC/5 8.48 lOOufd/16v ...17c 10/11.32 IC/511,22 This memory card is for the most part a
IOOufd/6.3v 90 10/740 1C/1 6.32 100ufd/25v 200 10/51.57 1C/113.30 universal u that can be used in almost any
-Calculators,
. e

100ufd/16v .,,11c 10/865 1C/5 7.28 100u1d/50v ..,29c 10/12.32 IC/119.70 UNDERSTAND DIGITAL ELECTRONICS e, from a HOMEBREW to an
100ufd/25v

lufd/50v
-
13c 10/11,08
Axial Load
11c 10/900
- IC/S 9.15

1C/1 7.65
220ufd/16v ... 20c
220udd/25v
330ufd/16v
29c
29c
...
,..
10/51.57
10/52.35
10/52.35
1C/553.30
1C/519.96
1C/519.96
Microprocessors, clocks. New programmed learning
courses. Design of Digital Systems, 6 volumes, only $14.95.
ALTAIR 8800. It uses an array of 21021k,
1 static random access memories Io produce
a 1024 s 8 memory compatible with mosl
2,2ufd/SOv 12c 10/925 1C/S 7.82 330ufd/25v .. 32c 10/12.54 1C/521.62
3.3ufd/355 .. 12C 10/93c 1C/S 7,91 470ufd/165 32c ,.. 10/52.54 1C/121.62 Digital Computer Logic, 4 volumes, $9.95. Both $19.95. Un- standard microcomputer system,.W5 Prov,de
everything from the sucer low noix vector
3,3054/507 128 10/980 1C/S 8.31 470094/255 ,..37c 10/52.98 1C/525.36 conditional refund if dissatisfied. Cambridge Learning, 300 Iog,c card, to fine quality low profile lockets.
4.7ufd/35v .., 125 10/93c 1C/5 7.91 1000ufd/160 . , 39c 10/53.13 IC/526.61
East 56th Street. New York, N.V. 10022. to me eight 2102'1. We even include timing
50654/160 115 10/905 1C/5 7.65 1000ufd/25v ..56c 10/S4.50 1C/538.23
10ufd/25v , 12c 10/985 1C/S 8.31 2200ufd/16v .. 62c 10/14.94 1C/541,98 diagrams eM taneulumn bypass cap...
DISC CAPS HARDWARE
100pf/500v ... 4c
... 4c
10/360 2C/S 6.09 2 -561/4 Screw.... 90c/C 1 7.20/M TREASURE FINDERS $69.95 Per Kit
220pf/500v 10/36c 2C/1 6.09 2 -561/2 Screw.... 980/C 7.80 /M
470pí/500v ... 4c 10/36c 2C/S 6.09 4-40 1/4 Screw.... 96c/C
S
S 7.80 /M
1000pf /5005 4c 10/370 2C/S 6.22 4-40 1/2 Screw.. 92c/C S 7.30/M FREE FACT -FILLED CATALOG! World's largest selection!
VOLT AMP T2 L SUPPLY
,

2200pí /500Y
4700pf /5005
..
..
4c
4c
10/37c
10/32c
2C/S 6.22 6-32 1/4 Screw.... 92c/C
632 1/2 Screw.... 88c/C
S 7.30/M
Metal detectors starting at $79.50. Two year guarantee! 5 1
2C /S 5.41 S 7.00 /M
.01ufd /5005... 6c 10 /50c 2C /S 8.55 8-32 3/8 Screw .. 51.05/C S 8.40/M Three factories, U.S.- Canada. 1,200 dealers - Service
.01ufd /505 3c ... 10/24c 2C /5 4.05 8-32 5/8 Screw .. 11.35/C 510.80/M
.0221Ád /255... 3c 10/280 2C /S 4.73 256 Hex Nun 11.35 /C ... $10.80 /M Centers nationwide. Finest instruments at any price! VOLT
5 1 AMP
.0470d/25v... 55 10/420 2C /5 7.17 4-40 Hex Nun 11.45/C ... 111.60/M Budget Terms. Dealer inquiries invited. Write: White's
.lord /255 .... 8c 10 /620 2C/510.57 6-32 Hex Nut 11.45/C , . ,
111.70/M
Electronics, Inc. Dept. PD5W, 1011 Pleasant Valley Road,
T'L SUPPLY
8-32 Her Nut 11.50 /C .., 511.80 /M
SILICON DIODES No. 2 Lock Washer. 450 /C 1 3.50/M Sweet Home, Oregon 97386. This is a standard TTL power supply using
No. 4 Lock Washer. 455/C the well Known LM309K regulator IC to
184148.. 10/40c 10/53.50 1M/534.00 S 3.50 /M

564001.. 10/70c 1C/56.13 1M/559.50 No. 6 Lock Washer. 450C S 3.50/M TREASURE FINDER locates buried gold, silver, poins, Ovide a solid AMP of current et 5 volts.
1

No. 8 Lock Washer. 452/C 3.50/M We try to make things easy for you by
1E14002.. 10/72c
treasures. 6 powerful models. Instant financing available.
0010,
C/56.30 1 1 M/561.20 S

N40o3.. 10 /74c C/56.48 M/162.90 Providing everything you need in ne pack

1

164004.. 10/76c 1C/56.65

1 1

IM/164.60 REED RELAYS

5 V. Cá1... 51.70 Write or call for freE' catalog. Phone (713) 682 -2728 day or age, Ince..the hardware for only
154005.. 10/82c 1C /57.18 1M/569.70 6 V. Coil 11.70
164006.. 10/90c 1C/57.88
6 AMP SPST N.O. 12V. Coil
, ,

... 57.70
,

night. Dealer inquiries invited. Relco, Dept. AA20, Box

1 M /176.50
CONTACTS ... 1l.70 10839, Houston, Texas 77018.
164007.. 10/99c 1C/58.75 1M /585.00 245. Coil
$9.95 Per Kit
1/2 & IA WATT CARBON COMP. RESISTORS
5 each of the 85 standard 10% values (2.2 -22M) 1st W Resistors (425 pcs.) REAL ESTATE
Sorted by value 513 /set 2 -4 ore 112 /sat 5 -9 are S11 /set.
5 each of the 70 standard 10% values (10 -5.6M) 4. W Resistors (350 pcs.)
PLASTIC INSTRUMENT CASE
Sorted by value 513/set 2 -4 ore S12 /set 5 -9 ore 511 /set.
BIG NEW FALL CATALOG! Over 2,600 top
FREE.
MOLEX SOLDERCON IC TERMINALS , .

values in 40 states coast to coast! UNITED FARM These cases are fine
4,alay urnts made by a
100 /11 500/54.20 1000 /56.20 5000/538.20 50,000/5275
AGENCY, 612-EP, West 47th St., Kansas City, Mo. 64112. Germen manufacturing firm wh,ch tit to the
dimensions of our DVM and COUNTER kit
VOLUME DISCOUNT SCHEDULE I.C. SOCKETS with room enough left for power supply or
.erekaea EMr[YrAse
Mane Ted Pin Solder -Tab 17c batteries. Excellent for many other projects
Ted
S 0.015 9.99.... NET
Reuere
f 100.065499.00 LESS 15%
8
14 Pin Solder -Tab
.

. 207 RECORDS as well. Dimensions 2"x 3.1/8"x 57/8 ".

S 10,005 24.99. 1250 3% 5 5!3.06509.99 LDS 30% 16 Pin Solder -Tab .. 22,
18 Pin Solde.Tab .. 29,
S

- Tb.,,
15.005 99.99165 101
Add the Standrad Charge Selen
51010.00 8 up.. LESS 255.
24
28
Pin
Pin
Solder -Tab
Solder -Tab
,. 38c
.. 45c
OLDIES. 45rpm. Free Catalog. Corny's Record Shop, Box
STANDARD SHIPPING /HANDLING ., 43c 166TM, Mason, Ohio 45(140.
CHARGE
40
8
Pin
Pin
Solde -Tab
Wire -Wrap .. 34c $5.95 Per Case
.. 52c FREE RECORD COLLECTION Reviewers wanted. Anyone
An* Mr.n, 14 Pin Wire-Wrap

--
II nw wwthrdire led .her le
.. 58c Satisfaction Guaranteed. $5.00 Min. Order. U.S. Funds.
f
16 Pin Wire -Wrap
Wire -Wrap .. 601
qualifies. We ship you new records to review. You pay
0.005 4.99 odd T2.00 50.00599.0. Md 57.30 18 Pin
S 5.065240 ..
.

add 5075
5
5100.00 8 up .. No Charge 24 Pin Wire -Wrap , . 960 postage. Records are tree. Applicants accepted "first Add $1.25 for Postage Write for FREE 19755 Catalog
5 75 00549.99 , odd 51.50 28 Pin Wire -Wrap S1.12 .

come" basis. Write: Research PE, 6162 Washington Circle, California Residents Add 6% Soles Tax

Ml/ÍES
hd,dw WNW. t harm. to USA e Comae 40 Pin Wire -Wrap, 51.56
Sad h het melee Milwaukee, Wisconsin 53213.
sel noire
COO ORDERS
SHIPMENT -
AMSTED
CALL
EOS SAME DAY
2184814474 aller
"Un(y pSeliFr Components sn,lrc.' RUBBER STAMPS
P.O. BOX 822, BELMONT, CA. 94002
DIGI -KEY CORPORATION"
°O. Box 677 Thief River Falls, MN 56701 RUBBER address stamps. Free catalog. 45 type styles.
Jackson's, Box 443G, Franklin Park, III. 60131.
PHONE ORDERS - (415) 592 -8097
CIRCLE NO 19 ON FREE INFORMATION CARD CIRCLE NO. 62 ON FREE INFORMATION CARD

108 POPULAR ELECTRONICS

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 NOT WORTH AS MUCH AS IT USED TO BE, WE ALL MUST
IS

Money CAREFUL TO GET TOP VALUE PER COST. COMPARE

BE
THESE PRICES WITH OUR COMPETITORS' (DON'T FORGET
SCHOTTKY TTL
TO INCLUDE VOLUME DISCOUNT) AND SEE IF YOU WON'T SPECIAL CLOSEOUT Catalog Unit
Number Price
GET MORE FOR YOUR MONEY. REMEMBER, OUR'S ARE FACTORY TESTED, SALE on 74500 series 74901 .50
FIRST RUN PRIME PARTS- NOT FACTORY FALLOUTS OR SECONDS. IF YOU'RE A Schottky TTL. This is a 74503 .50
REGULAR CUSTOMER, INQUIRE ABOUT OUR NEW BLANKET DISCOUNT. 74504 .55
one -time offer, as we are 74505 .55

SEMICONDUCTORS discontinuing our line of

this fast TTL. These
74309
74515
74520
.50
.50
.s0
Solid State Systems, Inc. has in stock a wide range of items are offered at our 74321 :50
SEMICONDUCTORS including 7400 TTL, Linear IC's,
Diodes, Transistors, and TRIAC's.
7400 SERIES cost, but only while
74522
74540
.50
.55
Unit Unit 74350 .50
These items are ALL factory tested FIRST -RUN
Catalog Catalog they last. These items 74351 .50
Number Price Number Price
PRIME. All IC's are supplied in 18 -, 14 -, 16 -, or 24 -pin 7400 .20 7484 2.80
will NOT be backorder- 74560 .50
74565 .50
DIP plastic or ceramic package except for NE540 and 7401 .20 7485 1.40 ed and credit will be 74574 .99
5E540, which come in a TO -3 package. 7402 .20 7486 .45
issued for all items 74576 .99
7403 .20 7489 3.50
Catalog Unit 74378 .99
Descrition 7404 .21 7490 .68 SOLD OUT.. Get them 745107 .99
Number Prices 7405 .21 7491 1.00
12 -17501 NE501A Video Amplifier 2.50 7406 .40 7492 .68 while they are still in 745112 .99
745113 .99
12 -27531 NE531 V High Slew Rate OP Amp 2.60 7407 .40 7493 .68 stock! 745114 .99
12 -37540 NE540L Power Driver 2.00 7408 .22 7494 .98
12 -35540 SE540L Power Driver 4.00 7409 .22 7495 .98
12.17550 NE550A Precision Voltage Regulator 1.00 7410 .20 7496 .98
82 -03554
12 -27555
SI- 3554E, 5V 3 Amp Voltage Reg
NE555V Timer
7.50
.80
7411
7413 .45
.21 74100
74104
1.25
.60 4000
12.25556
12 -25558
12 -17560
N5556V Operational Amp
N5558V Duel Operational Amp
NE5608 Phase Locked Loop
1.50
.68
2.25
7416
7417
7418
.38
.38
.30
74105
74107
74121
.60
.42
.48
CMOS SERIES
12 -17561 NE561B Phase Locked Loop 2.25 7420 .20 74122 .60
12 -17562 NE562B Phase Locked Loop 2.25 7421 .20 74123 1.00 Calog Description
12 -17565 NE565A Phase Locked Loop 2.25 7423 .40 74141 1.25 Number Prices

12 -27566 NE566V Function Generator 2.25 7425 .40 74145 1.21 4000 Dual 3 -Input Positive NOR Gate Plus Inverter .29
12 -27567 NE567V Tone Decoder PLL 2.25 7426 .26 74150 1.42 4001 Quad 2-Input Positive NOR Gate .29
12 -15595 N5595A Linear 4 -Quad Multiplier 2.25 7430 .20 74151 1.00 4002 Dual 4 -Input Positive NOR Gate .29
12-15596 N5596Á Balanced Modulator -Demod 1.65 7437 .44 74153 1.25 4006 18 Stage Static Shift Register 2.55
12.25709 709CV Operational Amp .38 7438 .44 74154 1.95 4007 Dual Complimentary Pair Plus Inverter .29
12 -15710 710CA Voltage Comparator .30 7440 .20 75155 1.25 4008 4-Bit Full Adder W /Parallel Carry Out 1.36
12 -15711 711CA Dual Voltage Comparator .32 7441 1.00 74156 1.25 4009 Hex Buffer, Inverting Type .74
12 -15723 723CA Precision Voltage Reg .85 7442 1.00 74157 1 .30 4010 Hex Buffer, Non -Inverting Type .74
12 -15733 733CA Differential Video Amp 1.40 7443 1.00 74158 1.30 4011 Quad 2-Input Positive NAND Gate .29
12 -25741 741CV High Performance Op Amp .45 7444 1.00 74161 1.50 4012 Dual 4 -Input Positive NAND Gate .29
12-15747 747CA Dual Operational Amp .95 7445 1.20 74162 1.50 4013 Duel D -Type Flip-Flop W /Set -Reset .67
12 -25748 748CV High Performance Op Amp .35 7446 1.00 74163 1.50 4014 8 -Stage Static Shift Register 1.86
7447 1.50
DIODES
2110270 N270 Germanium Switching Diode
1 .12 7448
.90
1.00
74164
74165 1.50
4015
4016
Dual 4 -Stage Static Register
Quad Bilateral Switch
1.79
.67
42 -14001 1N4001, 1Amp, 5OPRV, Rec Diode .07 7450 .20 74166 1.50 4017 Decade Counter /Divider WlDacoded Outputs 1.69
42 -14002 1N4002, 1Amp, 100PRV, Rec Diode .08 7451 .20 74170 2.75 4018 Presettable Divide- By --"N" Counter 1.86
42 -14003 1N4003, 1Amp, 200PRV, Rec Diode .09 7453 .20 74175 2.00 4019 Quad AND-OR "Select" Gate .67
42 -14004 1N4004, 1Amp, 400PRV, Rec Diode .10 7454 .20 74176 1.75 4020 14 -Stage Ripple-Carry Binary Counter /Divider 1.86
42 -14005 1N4006, 1Amp, 600PRV, Rec Diode .11 7459 .20 74177 1.75 4021 6 -Stage Static Shift Register 1.79
42 -14006 1N4006, 1Amp, 800PR V, Rec Diode .12 7460 .20 74180 1.00 4022 Divide By -B Counter W/8 decoded outputs 1.69
42 -14007 1N4007, 1Amp, 1000PRV, Rec Diode .13 7470 .32 74181 3.95 4023 Triple 3 -Input Positive NAND Gate .29
42.14148 1N4148 Silicon Switching Diode .08 7472 .29 74182 .95 4024 7 -Stege Binary Counter 1.43
73-10746 1N746A, 3.3V, 5 %, 400MW, Zener Diode .15 7473 .40 74192 1.25 4025 Triple 3 -Input Positive NOR Gate .29
73 -10747 1N747A, 3.6V, 5 %, 400MW, Zener Diode .15 7474 .40 74193 1.25 4026 Decade Counter /7 -Seg. Decoder, Disp. Enable 2.89
73 -10748 1N748A, 3.9V, 5 %, 400MW, Zener Diode .15 7475 .64 74196 1.95 4027 Dual J -K Master -Slave Flip -Flop W /Set & Reset .84
73 -10749 1N749A, 4.3V, 5 %, 400MW, Zener Diode .15 7476 .42 74197 1.95 4028 BCD -To- Decimal Decoder 1.43
73 -10750 1N750A, 4.7V, 5 %, 400MW, Zener Diode .15 7480 .50 74198 2.65 4029 Presettable Up /Down Counter, Binary or BCD 2.11
73 -10751 1N751 A, 5.1V, 5 %, 400MW, Zener Diode .15 7482 .93 74199 2.65 4030 Quad Exclusive -OR Gate .67
73-10752 1N752Á, 5.6V, 5 %, 400MW, Zener Diode .15 7483 1.30 4033 Decade Counter /7 -Seg. Decoct. & Ripple Blank. 3.23
73 -10753 1N753A, 6.2V, 5 %, 400MW, Zener Diode .15 4035 4 -Stage Shift Register (Parallel -In, Parallel Out) 1.86
73 -10754 1N754A, 6.8V, 5 %, 400MW, Zener Diode .15 4040 12 -Stege Ripple -Carry Bin. Counter/Divider 1.86
73.10755 1N755Á, 7.5V, 5 %, 400MW, Zener Diode .15 If your merchandise total is between:
1.35
4041 Quad True /Compliment Buffer
73 -10756 1N756A, 8.2V, 5 %, 400MW, Zener Diode .15 4042 Quad Clocked "D" Latch 1.28
73-10757 1N757Á, 9.1 V; 5 %, 400MW, Zener Diode .15 STANDARD CHARGES 1.26
4043 Quad NOR R/S Latch
73-10758 1N758A, 10V, 5 %, 400MW, Zener Diode .15 4044 Quad NAND R/S Latch 1.26
73-10759 1N759A, 12V. 5 %, 400MW, Zener Diode .15 $ 0.00 - $ 4.99 add $2.00
Hex Buffer /Converter, Inverting Type .72
$ 5.00 $24.99 add $0.75
TRANSISTORS
54 23860 2N3860 NPN General Purpose Transistor .21 $ 25.00
-

- $49.99 add $0.50

4050 Hex Buffer /Converter, Non -Inverting Type .72
4051 Single 8-Channel Multiplexer 2.11
$ 50.00 $99.99 add $0.25
TRIACS
45 -03003 3mA Gate 50V 3 Amp. TRIAC 1.31 5100.00
-

and up NO CHARGE
4052 Differential 4- Channel Multiplexer 2.11
4053 Triple 2- Channel Multiplexer _2.11
45 -03203 3mA Gate 200V 3 Amp. TRIAC 1.69 The above charges include shipping via 4060 14 -Stage Ripple -Carry Bin. Count./Div. W /Osc. 2.55
45 -03403 3mA Gate400V 3 Amp. TRIAC 2.11 First Class or UPS (your Choice), and 4066 Quad Bilateral Switch 1.26
45 -10003 10mA Gate 50V 3 Amp. TRIAC 1.06 insurance for all domestic shipments. 4071 Quad 2.Input OR Gate .36
45-10203 10mA Gate 200V 3 Amp. TRIAC 1.36 4072 Dual 4 -Input OR Gate .36
45 -10403 10mA Gate 400V 3 Amp. TRIAC 1.70 SPECIAL CHARGES 4073 Triple 3_Input AND Gate .36
45 -25003 25mA Gate 50V 3 Amp. TRIAC .85 4075 Triple 3 -Input OR Gate .36
4525203 25mA Gate 200V 3 Amp. TRIAC 1.19 COD $1.00 -additional 4081 Quag 2-Input AND Gate .36
45 -25403 25mA Gate 400V 3 Amp. TRIAC 1.53 Air Mail $0.50- additional 4082 Dual 4 -Input AND Gate .36
45 -50010 5OwA Gate 50V 10 Amp. TRIAC .84 Postal Insurance $0.25- additional 4502 Stobed Hex Inverter /Buffer 1.28
45 -50015 50mA Gate 50V 15 Amp. TRIAC 1.31 Special Delivery $0.75- additional 4510 BCD Up /Down Counter 1.96
45 -50210 50mA Gate 200V 10 Amp. TRIAC 1.36 4511 BCD -To -7 Seg. Latch/Decoder /Driver 1.96
45 -50215 50mA Gate 200V 15 Amp. TRIAC 2.33 4512 8- Channel Data Selector 2.13
VOLUME DISCOUNT SCHEDULE
45 -50410 50mA Gate 400V 10 Amp. TRIAC 1.72 4514 4 -Bit Latch /4- 16- Decoder(Hi) 2.47
45 -50415 50mA Gate 400V 15 Amp. TRIAC 2.95 4515 4 -Bit Latch /4- 15- Decoderi Lol 2.47
Merchandise Total Discount
46-50010 50mA Gate 50V 10 Amp. TRIAC .75 4516 Binary Up /OOwn Counter 1.96
46 -50015 50mA Gate 50V 15 Amp. TRIAC 1.18 $ 0.00 -$ 9.99 NET 4518 Dual BCD Up Counter 2.04
46 -50215 50mA Gate 200V 15 Amp. TRIAC 2.10 $ 10.00 - $ 24.99 Less 5% 4520 Dual Bin. Up /Down Counter 2.04
46 -50410 50mA GAte 400V 10 Amp. TRIAC 1.55 S 25.00 - $ 99.99 Less 10% 4528 Dual Monostable Multivibrator 1.69
4650415 50mA GAte 400V 15 Amp. TRIAC 2.60 $ 100.00 - $499.99 Less 15% 4585 4 -Bit Magnatude Comparator 2.13
500.00 $999.99
- Less 20%

SEND YOUR ORDER TO: $1000.00

$ and uD
OR CALL: 800- 325 -2981 Less 25 °'

SOLID STATE SYSTEMS, INC.

P. O. BOX 617 master charge
iRS cars Resax CRD
BANKAMERICARD

i Itylniur /Iirc
1-1 COLUMBIA, MISSOURI 65201
SEPTEMBER 1975 109

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BOOKS AND MAGAZINES REMAILS
Popular Electronics
FAST CONFIDENTIAL, your mail received. forwarded from
FREE catalog aviation /electronic /space books. Aero
Publishers, 329PE Aviation Road, Fal!brook, California
mini computer capital of the world. B.J., Box 441, Maynard, SEPTEMBER 1975
MA 01754.
92028.
FREE book prophet Elijah coming before Christ. Wonderful ADVERTISERS INDEX
bible evidence. Megiddo Mission, Dept. 64, 481 Thurston MAGNETS
Rd.. Rochester. N.Y. 14619.

READER PAGE
MAGNETS. All types. Specials -20 disc, or 10 bar, or 2 stick,
or 8 assorted magnets, $1.00. Magnets, Box 192 -H, SERVICE NO. ADVERTISER NUMBER
HYPNOTISM
Randallstown, Maryland 21133.
1 A.D.R. Audio Video 92
SLEEP learning, Hypnotic method. 92% effective. Details 2 A P Products Incorporated 2
free. ASR Foundation, Box 23429EG, Fort Lauderdale. MISCELLANEOUS 14 Ace Electronic Parts 79
Florida 33307. 64 Active Electronic Sales Corp 101
WINEMAKERS: Free illustrated catalog yeasts, equipment. 3 Adva Electronics 98
FREE Hypnotism. Self- Hypnosis. Sleep Learning Catalog!
Drawer H400, Ruidoso, New Mexico 88345. Semplex, Box 12276P, Minneapolis, Minn. 55412. 68 Allison Automotive Company 90
6 Alpha Electronics 93
AMAZING self- hypnosis record releases fantastic mental CORVAIR PARTS -1300 different Corvair parts stocked:
power. Instant results! Free trial. Write: Forum (AA9), 333 7 Altaj Electronics 111
large catalog $1.25. Clark's Corvair Parts, Shelburne Falls,
North Michigan, Chicago 60601. Mass. 01370. 8 Ancrona Corp 99
9 Audio Technica U.S. Inc 73
10 B &K Precision, Products of Dynascan 7
INTEL 8080 CPU $169.00 TRANSISTOR SPECIALS C/MOS (DIODE CLAMPED) 11 Babylon Electronics 100
8008 8 BIT MICRO PROCESSING 2N6517 NPN Si TO-92 441.00 74CO2 -$
.50 CD4019-$ .58
CHIP (with data book)
2102-2 1024 BIT RAM
$35.00
$3.95
2N5086 PNP Si T0-92 411.00 74C10 -$
.50 CD4022-$1.25
Bell & Howell Schools 18 19, 20, 21
2N4898 PNP TO-66 $ .60 74C157-$2.00 CD4023-$ .30 CREI Capitol Radio Engineering
5202A UV PROM $19.00 2N404 PNP GE TO-5 5/$1.00
MM5203 UV PROM $19.00 CD4001-$ .30 CD4024-$1.00 Institute 46, 47, 48, 49
2N3919 NPN Si T0-3 RF $1.50 CD4002-$ .30 CD4025-$ .30
1702A UV PROM $19.95 MPSA13 NPN Si T0-92 3/$1.00 Chien -Chang Industrial Co. Ltd 82
2N3767 NPN Si TO-66 .70 CD4006-$1.50 CD4026-$ .67
MINIATURE TRIM POTS 12 Circuit Design, Inc 87
2N2222 NPN Si TO-18 5/ 1.00 CD4007-$ .30 CD4027-$1.20
5K, 10K, 25K, 50K, 100K. 200K 2N3055 NPN Si TO -3 .80 CD4009-$ .67 CD4028-$1.09 13 Cleveland Institute of Electronics, Inc 64, 65, 66, 67
$.75 ea. 3/$2.00 2N3904 NPN Si TO-92 5/$1.00 CD4010-$ .67 CD4029-$1.42 15 Continental Specialties Corp 17
2N3906 PNP Si TO-92 5/$1.00 CD4011-$ .30 CD4030-$ .30
MULTI -TURN TRIM POTS 2N5296 NPN Si TO 220 5 .50 16 Crown 81
Similar to Boums 3010 style 3 16" 2N6109 PNP Si TO-220 $ .55 CD4012-$ .30 CD4035-$1.42 17 Delta Electronics Co 102
11/4", 50, 100, 2000. 5000 2N3866 NPN Si TO-5 Si RF CD4013-$ .53 CD4042-$ .84
ohms. $1.50 POWER $ .75 CD4015-$1.17 CD4046-$2.55 18 Delta Products, Inc 56
LIGHT ACTIVATED SCR's MJ2252 NPN Si TO-66 $ .90 CD4016-$ .63 CD4047-$3.10 19 Digi -Key Corporation 108
TO- 18200V lA
2N3638 NPN Si TO-5 5/51.00 CD4017-$1.34 CD4050-$1.05
$1.75 2N2218A NPN Si TO-5 4/$1.00 Dixie-Hi Fidelity 89
C D4018-$1.45 CD4055-$2.70
PRINTED CIRCUIT BOARD 20 EICO 93
CAPACITORS DO -33 -A 3 DIG. LED
41/2"x 61/2" single sided epoxy 35V at .47 LIF TANT $1.00 ARRAY READOUT $1.65 Full Wave Bridges 21 Edmund Scientific Co 95
board, 1/16" thick, unetched 35V at 6.8 OF TANT 3'$1.00 MAN -1 READOUT $1 75 22 Edmund Scientific Co 112
$.50 ea. 5/$2.20 20V at 150 OF TANT .5 .40 MAN -3 READOUT.. $1.00 PRV 7A 6A 25A
Conductive Elastometer low Profile 6V 30 OF TANT MAN -4 READOUT ..$1.30 200 .95 1.25 3.00 23 Electronic Distributors, Inc 90
Calculator keyboard $6.00 12V 200 OF ELECT ..$.30 MAN- 7READOUT $1.25 400 1.15 1.50 4.00 G C Electronics 6
200V 4.7 OF ELECT ...$.30 SLA -3 $4.50 WU 1..iS 1.75 5.00
2N5460 P FET $ 45 24 Godbout Electronics, Bill 82
CD 201
TIS 73 N FET $ 45 100x100 4 WATT IR 5 Heath Company 74, 75, 76, 77
IMAGE SENSOR
2N4891 UJT CHARGED COUPLE
LASER DIODE $7.95
DEVICES 63 Illinois Audio 94
ER900 TRIGGER DIODES 441 00 USED IN SOLID STATE CAMERAS, CD 110 LINEAR 256 X1 BIT SELF
WITH APPLICATIONS _ $145.00 25 International Electronics Unlimited 106
2N6028 PROG. UJT $ 65 SCANNING CHARGED COUPLED
FPA 711 -7 LEVEL Diode Array Op- DEVISE, WITH DATA $125.00 26 James 107
VERIPAX PC BOARD tical Tape Readers $5.95 62 James
This board is 1/16 single sided SANKEN AUDIO POWER AMPS 108
Low cost digital volt meter kit
paper epoxy board, 41/2 "' 61/2". Si 1010 G 10 WATTS 6.90 33 Johnson Co., E.F. 25
contains integ. circuit schem., $
DRILLED and ETCHED which PC boards. LED displays, reg- Si 1020 G 20 WATTS $13.95 27 Labtronics, Incorporated 92
will hold up to 21 single 14 pin ulators. Outer case and battery Si 1050 G 50 WATTS
IC's or 8, 16 or LSI DIP IC's with $24.95 28 Lafayette Radio Electronics 85, 86
not supplied, accurate to - one
busses for power supply con- count, has range of one my to LINEAR CIRCUITS 29 Linear Systems, Inc 15
nector. $5.25 999 VDC. Overall dimensions
1 LM 309K 5V 1A REGULATOR $1.50 30 McIntosh Laboratory, Inc 73
REDGREEN BIPOLAR LED $1.30 3'y 5" $62.00 723 -40 - 40V REGULATOR 5.58
MT -2 PHOTO TRANS 31 MITS 13
$.60 TTL IC SERIES 301/748 -Hi Per. Op. Amp. $.30
MV 5053 YELLOW GREEN 307 OP AMP $.28 32 Mallory Distributors Products Company 32
OR ORANGE LED 35 ea. 74L00- .30 7476- .45 CA 3047 - HI PERFORM OP AMP $.95
RED GAP OSL -3 LED 0.20 7400- .17 7480- .60 CA 3089 FM IF SYSTEM .. $3.25
34 Martin Research 59
14 PIN DIP SOCKETS 0.40
7401- .17 7483- .99 LM 320 -5 or -15V REG $1.75 35 Maxell Corporation of America 45
16 PIN DIP SOCKETS 0.50
7402- .17 7485 -1.10 741A or 741C OP. AMP... 5.31
7403- .17 7486.- .48 36 Mini -Micro Mart 97
MOLEX PINS .. 100/01.00 709C OPER. AMP.. 5.25
1O00ß8.00 7404- .21 7490- .60 340T -5, 8, 12, 15, 18. 24V NRI Schools 8, 9, 10, 11
8 PIN MINIDIP SOCKETS 7405- .20 7491 -1.00 POS. REG. T0 -220
5.32
7406- .35 7492- .75 .$1.75 National Technical Schools 28 29, 30, 31
101 OPER. AMP HI PERFORM 0.75
10 WATT ZENERS 7407- .37 7493- .60 LM 308 Oper. Amp., Low Power
,

$1.05
37 New -Tone Electronics 102
3.9, 4.7 OR 18V .
5.75 EA. 7408- .18 7495- .80 747 -DUAL 741 0.65 38 Olson Electronics
1 WATT ZENERS 5.6 7409- .22 7496- .85 556 -DUAL TIMER $1.30
83
10 12 15 18 0R 22V 5.40 EA. 7410- .17 8267 -1.95 537-PRECISION OP. AMP. $2.60
39 Pace Communications 81
Silicon P. wer Rectifiers 7411- .27 74107- .40 LM 3900 -QUAD OP. AMP 40 PAIA Electroncs
7412- .45 74121- .50 5.49 89
PRV lA lu LM 324-QUAD 741 $1.70
7413- .72 74123- .90 41 PanaVise 88
I»BmNEMIIIri
1 1 u

560 -PHASE LOCK LOOP 52.00

100 7414 -1.75 74125- .60 561 -PHASE LOCK LOOP 42 Phase Linear Corporation
201 IFIENORIM IBITi 7416- .37 74126- .64 -565 -PHASE LOCK LOOP
$2.00
$2.00
63
-.. 117,111FIIIIIMMEINIB 7417- .37
7420- .17
74150- .99 566 FUNCTION GEN. $2.00
54 Pickering and Compancy, Inc THIRD COVER
1111.111011M11711 74151-
.

600 .85 567 -TONE DECODER ... $2.00 43 Poly Paks 105
:11 IlTalrrilEr17 7425- .36 74153 -1.05 703-RF -IF AMP... 5.41
1
7426- .27 74154 -1.48 44 Processor Technology Co 96
1000 ,20 .45 1.10 2.75 7427- .31
7430- .17
74155 -1.05
74157 -1.18 555-2 us
553 QUAD TIMER
-
LM 370 -AGC SQUELCH AMP
2 HR. TIMER
.$1.15
$.65
.$3.50
45
46
RCA Solid State
Royce Electronics
61

REGULATED MODULAR
7432- .27 74161 -1.25 FCD 810 OPTO- ISOLATOR ..$1.35
1

7437- .36 74163 -1.49 7456 OPER. AMP 5.95

47 SAE, Inc 16
POWER SUPPLIES 7438- .35 74164 -1.70 1458 DUAL OP AMP 48 Sansui Electronics Corp
7440- .17 $.65 27
- 15VDC AT 100ma 74165 -1.78 LM 380-2W AUDIO AMP. $1.29
115VAC INPUT $24.95 7441- .95 74173 -1.55 LM 377 -2W STERO AUDIO AMP $2.50
49 Schober Organ Corp., The 92
5VDC AT 1A, 115VAC INPUT $19.95 7442- .90 74175 -1.60 LM 381- STEREO PREAMP... $1.69 65 Sencore 91
12V .5A 24.95 7445 -1.05 74177-1.50 LM 382 -DUAL AUDIO PREAMP. $1.69
7446 -1.10 74181 -3.20 -HI
50 Shure Brothers Inc 23
IN 4148 (IN914) 14/$1.00 LM 311 PER. COMPARATOR 5.95
7447 -1.00 74192-1.40 LM 319 -Dual Hi Speed Comp. 51 Solid State Sales 110
7448 -1.00 51.15
1103 1024 but RAM $4.75 74193-1.29 LM 339 -QUAD COMPARATOR
7472- .33 $1.25 52 Solid State Systems, Inc
NEC 6003 2048 bit RAM $9.50 74195- .80 8038C IC VOLT CONT. OSC $4.40
109
1101 256 bit RAM $1.75 7473- .38 74196-1.90 53 Southwest Technical Products Corporation 14
8223 PROM $4.75 7474- .35 75324 -1.75 TRIACS SCR'S
7489 RAM $2.45 55 Stereo Discounters 92
58 Teco Electronics 87
Terms: FOB Cambridge, Mass. Send
Check or Money Order. Include
Postage. Minimum Order $5.00.
SPOT MIN TOGGLE SWITCH
DPDT MIN TOGGLE SWITCH
$1.50
$2.25 200
I r BRT1DRTrR7fi1FF11NEFDIMI
MEDIIiIC7IIRIIBImNELI
L11aRfE11ffi31]fA1g 11IRRirJ
1 s
1. 1

59 Teco Electronics
Tracy Design Corp
94
98
CT7001 Calendar Alarm
1

COD'S $20.00. CLOCK CHIP....... $6.75 1.70 E

1 1
EEd;1]BRaRa
1 1 .11 57 Tri -Star Corporation 94
Send 20c for our catalog featuring Transistors and Rectifiers; 145 Hampshire St., Cambridge, Mass. 66 U.S. Pioneer Electronics Corp SECOND COVER

'
4 United Audio Products, Inc THIRD COVER
61 Video Games 90
s,SOLID STATE SALES OFEOUR ORDERS THE 60 Wahl Clipper Corporation 93
P.O. BOX 74A DAY WE RECEIVE THEM 67 Weller -Xcelite Electronics Division 5
SOMERVILLE, MASS. 02143 TEL. (617) 547 -4005
CLASSIFIED ADVERTISING 96, 98, 100, 101, 102, 106, 108, 110
CIRCLE NO. 51 ON FREE INFORMATION CARD
110 POPULAR ELECTRONICS

www.americanradiohistory.com
 Altaj Electronic Bargains
PRICES SLASHED' WE WANT YOUR BUSINESS. SATISFACTION GUARANTEED ON EVERY ITEM

COMPUTER BOARD BONANZA C - MOS

CD4000 .24 C04015 1.19 CD4026 1.49 CD4044 .59
We bought over 4 tons of C04001
CD4002
.24
.24
CD4016
CD4017
.59
1.29
CD4027
CD4028
.59
.99
CD4047
C04049
.59
.59
CD4006 1.49 CD4018 1.49 CD4029 1.39 CD4050 .59
assorted boards. Contains CD4007 .24 CD4019 .59 CD4030 .49 CD4066 .99
CD4008 1.15 CD4020 1.59 CD4032 .24 C04077 .39 LM309K
TTL, diodes, transistors, etc. CD4009
CD4011
.59
.24
C04021
CD4022 -
1.49
1.19
CD4033
C04035
1.49
1.39
74CO2
74C04
.29
.29 TO -3 Case, AMP
1 5 VDC
5 board assmt. with 150 to CD4012 .24 C04023 .24 C04040 1.59 74C107 1.29 Voltage Regulator Brand New
C04013 .59 C04024 99 C04041 .89
250 IC's - S3.95.
C04014 1.49 C04025 .24 CD4042 79 By National $1.19

3 DIGIT LED READOUT ARRAY LITRONIX DL707

MAN -3 LED READOUTS
Lois Litronix DL -33 3 MAN -3 style read - READOUTS Brand new, factory prime units t2 In
outs In one package Factory new units 30 IN.CHAR. Common Anode. character Common cathode Perfect for
-
Designed tOf calculators. Special
$1.39 13 Digits) SPECIAL - $1.19 calculators
where'
39e ea. Best Price Any-

CALCULATOR CHIP BONANZA DIGI1AL ALARM CLOCK IC FLOURESCENT 1 AMP RECTIFIER RIOT!
PRICES SLASHED! READOUT TUBES
The newest and easiest to use chips
The newest and easiest to use alarm chip 7 Segments. 13133e-Green
Green color. We bought over 10 million
on the market today. Features: Mfg, by 15E. if40G8F. The most
available today. Made by famous US mfg. popular display used in many
feci or tusks and
- pieces untested. 1N4000
1. Single supply voltage.
All are 28 pin DIP. Features: direct LED
2. LED Intensity control chips.
use w ith clock
MM5316calculators. series. Also a few 1 watt
segment drive. low power consumption. 3. Simple time set. SUPER SPECIAL 69c ea. ZENERS mixed in. Sample
internal keyboard debounce, internal 12 For 55.95
clock oscillator, single supply voltage,
4. 4 or 8 Digit LED Display tests show this lot contains
5. AM -PM Indication
internal keyboard encoding, and floating 8. 24 Hr. Alarm.
many useable devices, some
decimal point. Does not require many 7. 10 minute snooze. even up to 1 KV. Sold as is
external components as do older types assorted, but you will be
like C75001, 5002, 5005, etc. We otter the
most sophisticated functions for the
lowest price anywhere.
Order #70250
8. Outperforms MM5316
- $6.95 (2 FOR 912) DIGITAL WRIST
WATCH CRYSTAL
happy. 100 PCS
500 PCS -
$4.95
S1.29 -
Chip 01 - 8 Digit, Constant, Six Func- MM5314 NATIONAL CLOCK CHIP
Brand new, mfg. by CTS -KNIGHT. 32.768
tion (-, -, 8, +, %,J) - $2.49 The most popular clock chip around. We
made a huge special purchase of factory
KHZ. Standard. most popular type.
Special $1.95
Free 28 Pin Socket with purchase of
any clock or calculator chip.
MOTOROLA MJE 3055 fresh, prime units. Lowest price in USA. s1 VALUE -FREE BONUS

90 Watts 15 Amps. SPECIAL -

Plastic version of 2N3055. NPN Silicon.
69c
24 Pin DIP. 4 or 8 Digits. With Specs.
$3.95
COLOR ORGAN CONTROL MODULE
Completely self-contained. Has SCR
circuitry, AC line cord, etc. From a SILICON TRANSISTORS
close out by a mfg. of color organs.
8008 MICROPROCESSOR New, unused. EN2222 NPN 8 For $1
CT7001 BY CAL -TEX $1.49
Computer on a chip. 8 Bit Digital alarm clock chip with calendar 2N2369 NPN 8 For $1
Parallel CPU. Can address 16k feature. 4 or 8 digits. Also has timing MOTOROLA SCR
circuitry for radio ON -OFF control fac- 2N4443 8 Amp 400PN, Plastic Power 2N3638 PNP 8 For $1
x 8 bits of memory. With tory fresh. Case. 69c
2N3904 NPN 6 For $1
specs. Factory tested units. 96.95 GE POWER DARLINGTON
NPN Plastic Power Tab Case. 2N3906 PNP 6 For $1
$24.95
VCEO -30 HFE- 30,000 TYP. Brand new 2N4400 6 For
2102-1K RAM's for above - JUMBO LED READOUT
Twice the size of regular readouts. .65
units, but leads are slightly trimmed
for P.C.B.
#D40C1 -
SPECIAL 39c 3 For $1
NPN $1

$4.95 or 8 For $30 inches. Like Litronix DL747. Outperforms

and easier to read than SLA -3, only 20 1024 BIT SIGNETICS P -ROM IN4004 RECTIFIERS
TTL SUPER SPECIAL
MA per segment. Our best readout for 8251291 -256X4 bipolar. field pro -
AMP 400PIV - SPECIAL 15/$1
74121 -
ONE SHOT 41$1
digital clocks.
$2.95 ea (8 FOR $15) Common Anode
gramable ROM Fully TTL compa-
tible. 50 ns max address access
lime. Much faster than MOS type 7805 STYLE REGULATORS
LINEAR IC SPECIALS units. Perfect for code conver- TO -220 Plastic Case 5VDC Regulator.
555V -75c 567V -$1 .95 723CH -59c 741 CV -39c
LM324 by National -
Quad 741C in one DIP $1.19 - sions, microprogrammers, hand - Brand New by National 99c -
wired algorithms, controllers, etc
FACTORY NEW LED'S
With specs Regular $35 ea
12VDC REED RELAY
Coil is 500 OHM. SPST -No.
FILTER CAPS
1000 MFD 16VDC upright
SPECIAL 3.95 - Jumbo Red -Like MV5024 -81$1
Jumbo Green -Like MV5222 -5/$1
BEST MEMORY BUY IN USA, Jumbo Yellow -51s1
$1.49 Sub -Mini. style. 4 FOR $1 Mini Red -Like MV50 -10 /$1
FORD SOLID STATE MODULES
PRIME TTL DIP IC'S 803$ FUNCTION GENERATOR LOOK Mfg by Centralab for Ford car radios.
7400 -16c 7448 -89c 74151 -75c Brand new Voltage con- MOS 4 DIGIT COUNTER Eac h module contains 2 transistors
7402 -16c 7453 -16c 74153 -89c trolled oscillator. Has sine, An ALTAJ exclusive. These are plus other components. These modules
7404 -16c
7406 -24c
7473 -37c
7474 -37c
74154 -95c
74157 -99c
square wave, and triangular Out-
puts. $4.50 each
the latest state of the art, MOS
chips. By a famous US mfg.
Contains a complete 4 digit count-
include specs. -
were used as audio pre-amps. We
4 For $1

7408 -16c 7475 -65c 74161 -99c er, including 4 decade counters, TTL IC ASSORTMENT
7410 -16c 7476 -39c 74163 -1.19 latches, multiplexing circuits, dis-
play decoders, etc. Features: 5 Various types. Most are marked. Our beet
7413 -49c 7483 -85c 74164 -1.29
IN4148 DIODES VDC operation, 25 MW power selling assortment. Untested but in-
7420 -16c 7490 -69c 74165 -1 49 cludes many useable devices.
Brand New Units. Same as IN914. consumption, both 7 segment and
7427 -24c 7492 -75c 74174 -1.29 Full Leads. BCD outputs. Perfect for making 200 PCS FOR $3.95
7430 -16c 7493 -75c 74175 -1 39 6c each DVM's, frequency meters, tacho-
7437-39c 7495 -75c 74181 -2 75 meters. stopwatches. or any other
74192 -1 25 device requiring 4 or more digits. FM TRANSFORMERS
7438 -35c 7496 -75c
7440 -16c 74121-38c 74193 -1 25 MONSANTO COLORED Complete with specs. 28 PIN DIP. We bought a load of coils and
7442-69c
7447 -89c
74123 -75c
74150 -70c
74195 -79c
74197 -79c
READOUTS
.27 IN. Character. Common
QTY Limited
SPECIAL -
$12.50
BACK IN STOCK'
transformers that were used in Ford
AM -FM car radios. Includes 19KHZ,
38KHZ, OSC. Coils, etc. All New.
Anode
-- -
Perfect for experimenters or repair-

--
men. 10 Pc Asst. 99c
AUDIO AMP ASSEMBLY MAN 5 GREEN $1.29
From Audio Eqmt Mfg. Pc Board with MAN 8 YELLOW $1.29
SPECIAL -
2 watt lc Amp plus other components.
$1.49 Very Limited Oty. PHASE LOCKED LOOP
RCA CA3043 FM IC
Used in FM stereos. Contains IF
- ALTAJ ELECTRONICS
P O. BOX 38544
565A by Signetics. Extemely Amp, Limiter. FM Detector, and DALLAS. TEXAS 75238

P i
B RELAYS
stable. High linearity, wide fre-
quency range. TTL compatible.
an Audio Preamp and Driver all in
one 12 lead TO -5 package. With TERMS Check or money order. No COD.
4P.D.T Miniature Size
--
Perfect for tone decoders, FSK,
SCA receivers, frequency multipli-
Spec Sheets.
A $3.00 Valve 99c - Add 10% Pstg. and Hdlg. Tex Res. add
5 %.
24VDC Coil
115VAC Coil
1.49
1.79
cation and division -
$1.75.
WITH SPECS
CIRCLE NO 7 ON FREE INFORMATION CARD
SEPTEMBER 1975 111

www.americanradiohistory.com
 4 WHEN YOU COME TO PHILADELPHIA BE SURE TO SEE

LIVE IN THE WORLD FREE BICENTENNIAL LIGHT SHOW

IN BARRINGTON, N I ONLY 10 MINUTES AWAY AT

EDMUND FACTORY STORE

OF TOMORROW...TODAY!
OWN A WORKING
And our FREE 164 PAGE CATALOG is packed with
DUTCH WINDMILL
and science items -
exciting and unusual values in electronic, hobby
plus 4,500 finds for fun, study
or profit ... for every member of the family.
Easily build a charming 1i5 scale replica of the
real thing with our detailed plans, blueprints,
list of materials needed and explicit instruc-
tions. 8' size can generate 1000w (12v current)
of free electricity from the wind! 2', 4' & 8' sizes
A BETTER LIFE stand 3'6", 7' & 14' high, respectively. Get
kudos from your neighbors for the beauty

STARTS HERE & practicality. If you're the least bit handy you can do it for $250 -$350 (est.
complete material
Stock No. 9130AV
cost). Go Dutch!
$15.95 Ppd.

TOTAL KIRLIAN AM RADIO FITS

PHOTOGRAPHY SET IN /ON YOUR EAR!
Explore "aura" photography w superb new Wear it inconspicuously everywhere, listen as

search Unit. Terrific value -

sell-contained Kirlian Electrophotography Re-
introduced at
$99.95 ($140 in Sept.)! Has everything but
you work (lawn, yard, office), watch (game,
beach) or wait. Instant music, news, sports. No
gimmick -6/10 oz. technological wonder
vinyl photo changing bag. Ideal for color or circuit, 11 transistors, patented
w /integrated
b &w 35mm, sheet or Polaroid film for photos ferrite antenna/tuner /volume dial. Works best
up to 5 , 7" all without camera or lens. Variable voltage 12v to 32kv. Ultimate outdoors. Uses hearing aid batt. (incl) -up to 100
safety design -fully encased in plastic; patented electronics. Instrs. hrs. playing. New batt. to slip in avail. at drug stores (about 50r1. No lengthy wires,
No. 72,104AV ... (3 57,6 7i/e ") $99.95 Ppd. bulky cases, or power -packed!
No. 42,240AV .. (CHANGING BAG)
.
$ 6.50 Ppd. Stock No. 42,275AV $14.95 Ppd.

KNOW YOUR ALPHA FROM THETA!

ELECTRONIC DIGITAL For greater relaxation, concentration, listen to
STOPWATCH: $69.95 your Alpha -Theta brainwaves. Ultra- sensitive
electrode headband slips on /off in seconds -
A price breakthrough! New pocket size 4 oz. eliminates need for messy creams, etc. Atch'd
timer acc. to 2% of last digit (1.100 sec. in- to amplifier, filters brainwaves, signals beep for
ea. Alpha or Theta wave passed. Monitoring
crements). Compares with others twice the button stimulates Alpha sound; audio & visual
price! Instant error-free readouts to 9999.99 (L. E.D.) feedback. Reliable, easy -to -use unit comparable to costlier models. Com-
sec. (over 234 hr). Starts, stops re- starts (ac- pletely safe. Comprehensive instruction booklet
cumulates). Mechanical pushbutton & electrical remote on offs w any 3.5 -150v
AC /DC source. Plug-in jack. Incls. 9v batt. Solid state.
No. 1635AV (8 3 4"; 24 oz.) $149.50 Ppd.
DELUXE "ON" TIME MONITOR- Measures and records %
No. 1943 AV (21/4x41/4x7/e'") $69.95 Ppd. No. 1652AV (15 10 .6 ") $299.50 Ppd.
DELUXE 2 EVENT STOPWATCH (±-0.01% OF LAST DIGIT)
No. 1653 AV $149.95 Ppd. No. 71809AV LOW COST "STARTER" UNIT $55.00 Ppd.
00 -IT- YOURSELF KIT No. 61,069AV $34.95 Ppd.

THE FINAL OPTICAL

FUEL MISER RECLAIMS HEAT
Save your 40% wasted heat to warm a basement,
jo ILLUSION!
Now you see it, but you don't. Put a coin, ring,
garage or rec room at no extra cost! Instead of rock, any small thing inside the unit seems -it
going "up the chimney" it goes where you want it. to be resting on the mirrored top. Look at it,
Remove part of furnace exhaust pipe, slip Heat smell it, shine a light on it, even photograph it
Exchanger in. At 125 fan automat. forces
AND it's really there. Try to touch it, you'll get
clean air through unit which heats to over 200°F.. can be ducted to 20 ft. from unit.
110v AC.Inst. only thin air! You & everyone else will be
astounded by this Parabolic Display Unit (it's
No. 19,194AV (5 /e" DIA.) Shpg. 17 Ib $106.00 FOB science and art) that produces an amazing optical effect. Scientists call it a 3
dimensional real image. Very exciting!
No. 19,195AV (6" DIA.) Shpg. 17 Ib $106.00 FOB

No. 19,198AV (7" DIA.) Shpg. 17 Ib $106.00 FOB No. 72,074AV (w/4" dia. displ. stand) $45.00 Ppd.

3- CHANNEL 41/4" ASTRONOMICAL

COLOR ORGAN KIT TELESCOPE
Easy tobuild low -cost kit needs no See moon craters, rings of Saturn. double stars.
technical knowledge. Completed unit New equatorial mount. f 10. 1.4 wave mirror
has 3 bands of audio frequencies to mod- (Pyrex -). Gives theoretical limit of resolution.
ulate 3 independent strings of colored lamps Rack & pinion focusing. Aluminum tube, 6X
(i.e. "lows" -reds, "middles " -greens, "highs" - finder. 1" F.L. 45X Kellner achromatic eyepiece
blues. Just connect hi -fi, radio, power and Barlow lens to double & triple power up to
lamp etc. & plug ea. lamp string into 135X. Free Star Chart plus 2 Books.
own channel (max. 300w ea.). Kit features 3 neon indicators, color intensity Stock No. 85.105AV (Shipping Wt. 42 lbs.) $149.50 FOB
controls, controlled individ SCR circuits: isolation transformer; custom plastic 4Yá WITH CLOCK DRIVE No. 85,107AV $189.50 FOB
housing. instr. 6 REFLECTOR TELESCOPE (48X to 360X)
".
No. 85,187AV $249.50 FOB
Stock No 41,831AV $18.95 Ppd
6 WITH CLOCK DRIVE
".
No. 85,086AV $285.00 FOB
3 DELUXE REFLECTOR (300 to 90X) No. 80,162AV $ 79.95 Ppd.
STANDARD 3 REFLECTOR No. 85,240AV $ 49.95 Ppd.

MAIL COUPON FOR

GIANT FREE EDMUND SCIENTIFIC CO. 300 Edscorp Building, Barrington, N.J. 08007

CATALOG! PLEASE SEND GIANT

How Many Stock No. Description Price Each Total

164 PAGES MORE THAN FREE CATALOG "AV"

4500 UNUSUAL
e

BARGAINS
Compierely new 976 edoLon New items, categories, iil ustranons Dozen,
El Charge my BankAmericard
1

of elecrr.cal and elecaomo9,et, ports. accessories. Enormous selection of

Charge my Master Charge Add Handling Chg. $1.00, Orders Under $5.00, 50A, Orders Over $5.00
Astronomicol Telescopes. Unique lighting and ecological Items. Micro-
Interbank No.
scopes. Binoculors, Magnifiers, Magnets, Lenses, Prisms. Hard -to -gel_
surplus bargains. Ingenious scientific tools. 1000's of components
EDMUND SCIENTIFIC CO. My Card No. Is
GM I enclose (]check money order for TOTAL $
300 ilding, Barrington, N. 1. 01007
Please rush Free Giant Catalog "AV" Signature
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Name,
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-4
CIRCLE NO. 22 ON FREE INFORMATION CARO
112 POPULAR ELECTRONICS

www.americanradiohistory.com
 THE SOURCE
OF PERFECTIO\
I\ SOU\D.. ...tracks at one gram (or less)
in stereo and discrete
Pickering's engineers pursued the idea of a
totally new departure in cartridge design with
all the zeal of true crusaders. They had a
reason ... there was a demand for a pickup
to play both stereo and discrete (as well as
SQ and QS) with total and absolute precision
at one gram. That they succeeded is a
remarkable achievement because this cartridge
successfully tracks all types of records at
forces even lighter than one gram. It is a
real first to do it this accurately.

The XUV /4500 -Q features Pickering's

patented Quadrahedral® stylus assembly. The
Quadrahedral stylus assembly incorporates
those features that produce extended
traceAbilityTM for 4- channel as well as stereo.
This means that it possesses not only superior
performance in low frequency tracking, but
also in high frequency tracing ability. When
combined with the exclusive QuadrahedronTM
stylus tip, a brand new shape, it can truly be
called: "the Source of perfection in Sound ",
whether the playback requirement is stereo,
SQ, QS, or discrete 4- channel.

DATE 3/ Cvv,
'/r atypical curve of
CARTRIDGE

STYLUS _Q. I
lfy=W

M CO q
-33
the XUV /4500 -Q
IKC ourPUr Shown at left is a printout graph
from Pickering's testing apparatus.
The top line is a frequency response
CN. BALANCE
-40 curve (note that it starts at 1,000
RL ADO K cycles for the sake of simplicity). It
CL ç.Cff depicts the unusually flat frequency
T. F.
-45 response throughout the spectrum.
The bottom line, which also starts at
TEST RECOR
- 50 1,000 cycles, shows the separation
characteristics of this new cartridge.
Believe us, you have ñever seen
TRACKING
CAPABILITY ,1
7 - -55 one quite like this because Picker-
ing's exclusive new design devel-
dB
60 opment also makes it superior to
other cartridges in the playback of
VERT TR stereo records, as well as discrete.
ANGLE
-65
RESIST A E

-7o The specifications are so

INDUCTA
exciting that we hope you
TIP ... -)5 will write to Pickering and
RADIUS
Company, Inc., Dept. PE,
HUM SE
-60 101 Sunnyside Blvd., Plain-
TEST BY view, New York 11803 for
further information.

FREQUENCY IN CYCLES PER SECOND

PICKERING
CIRCLE NO 54 ON FREE INFORMATION CARO "for those who can (hear the difference"

www.americanradiohistory.com
 Every Dual, from the 1225 to the CS701, is
designed to fulfill one basic concept: to provide more
precision than you are ever likely to need.
Perhaps this is why more component owners- -

audio experts, hifi editors, record reviewers and

readers of the music /equipment magazines -own
Duals than any other turntable. These serious music
lovers, whose investment in records typically exceeds
their investment in equipment, prefer Dual for only
one reason. Quality.
Until recently, Dual quality has been available
only with fully automatic turntables with both
single -play arid multi -play facility. Now the choice is
much broader. Of the seven Dual models, three are
single -play only. Two of these are fully automatic: one
is semi -automatic. Dual turntables also use all three
types of drive systems: belt, rim and direct.
The way a tonearm is moved to and from the
record is not critical. Nor is the type of drive system.
What is critical is how faithfully the tonearm permits
the stylus to follow the contours of the groove and
how accurately and quietly the platter rotates.
If precision performance and reliability are
of primary importance to you -as they should be-
you'll find them in every Dual.

Dual 1225. Fully automatic, sinrgle- ploy/mul }i -play. Viscous damped

cue -control, pitch -control. 10 %' platter. $139.95, less base.
Dual 1226, with cast platter, rotating single -play spindle, $169.95.
Dual 1228, with gimballed tonearm, synchronous motor,
illuminated strobe, variable tracking angle, $199.95.
Dual 1249. Fully automatic, single -play /multi -play. Belt drive.
12" dynamically -balanced platter. S279.95, less base. Full size
belt -drive models include: Dual 510, semi -automatic, $199.95;
Dual 601, fully automatic, $249.95 (Dual CS601, with base
and cover, $270.)
Dual CS701. Fully automatic, single -play. D.C. brushless, electronic
direct drive motor; tuned anti- resonance filters. $400,
including base and cover.

United Audio Products, 120 So. Vernon, N.Y. 10553

Columbus Ave., Mt. U.S D,str,bution Agency for Duol
Exclusive
CIRCLE N0. 4 ON FREE INFORMATION CARD

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