DL-QRP-AG

DipIt, the ultimate Dipmeter

Manual Vers. 1.21
November 22.2007

© QRPproject Molchstr. 15 12524 Berlin http://www.QRPproject.de fone: +49(30) 85 96 13 23 e-mail: support@QRPproject.de

Manual: FIservice Peter Zenker DL2FI email:dl2fi@qrpproject.de

1
„DipIt“, the Super- Dipmeter“ of German QRP Club DL- QRP- AG Basics:
Design: Peter Solf, DK1HE
Project Coordination: Peter Zenker, DL2FI The mode of action of classic dip metres is based on the fact that the
Kit Realisation: Nikolai Zenker, DL7NIK amplitude of an L/C oscillator decreases if it is coupled to a resonant
Manual-Translation: Pete Meier, WK8S and Peter Zenker, DL2FI circuit working at the same frequency (the dip). If the oscillator is variable
and provided with a calibrated frequency scale, then it can be used easily
Preface:
Very often a home brewing radio amateur comes into the embarrassment to
measure the unknown resonant frequency of a receiver or transmitter
oscillating circuit or to adjust a post Mixer filter to the correct frequency.
Such or similar measurement tasks can be done easily with a so called
"dipper". The "old rabbits" beyond us know, this instrument used to be the
basic equipment of their amateur activity and often it was the only RF
measuring tool available when they constructed their noteworthy projects.
But using a dipper was allmost forgotten in the course of the
commercialization of amateur Radio for times. Now, when homebrewing in
HAM Radio has a renaissance, the dipper is more up-to-date than ever. It
can help to do lots of sophisticated measurements during homebrewing of
Radio Kits at low cost rates and it can eliminate the need to buy much to find the resonant frequency of an unknown L/C Circuit. To have a broader
more expensive test equipment if it is well designed. On multiple request of frequency range and good resolution at the samee time, most Dip Metres
DLQRP AG Club members the author developed a "Superdipper kit" which is use Plug in coils.
equipped with some extra practical additional functions apart from the real To find the resonate frequency of an unknown circuit, the DipMetre Coil
basic functions. usually will be couplet inductive or capacitive to the object to be measured.
Technical data: The actual amplitude of the VFO (or the proportional Grid current if it is a
- frequency range: 1-42 MHz (divided up into 5 areas by means of plug in tube Dipper, normaly can be controlled by using an analog Voltmeter.
coils) VHF / UHF Option with plug in Oscillator
- new highly sensitive "sweep-frequency method" All previous dipmeter more or less in common show the following weak
- frequency indication by 5-digit LED display points
- resonance display with a super bright light-emitting diode
- frequency tuning by 10- turn potentiometer The amplitude of the oscillator changes from the beginning to the end of
- heterodyne frequency meter with an additional headphone output +BNC the tuning range. It strongly dependends on the chosen frequency range.
input (with attenuator) All models have a sensitivity control, which permanent must be regulated
-absorption frequency measurement with optical display (LED) to keep the instrument at 2/3 of full scale where eventually a dip coud be

November 22.2007
- amplitude stable +7 dBm generator output for peripheral attachments seen at its best. At higher frequency it often is impossible to adjust the
(Antenna ananalyzer and other) instrument to 2/3 of full scale.
- integrated switching transformerr working with 4 AA batteries
- visual battery voltage control
2
 To achive good acuraccy and avoide detuning of the measured object, the The heart of the circuit is a varctor controlled VFO. The tuning range is
Dip Metres coil alway should be coupled as loose as possible. At the approximately an octave. The normal Tuning Voltage for the Varactor
recommended loose coupling however, sensitivity of a normal Dipmeter becomes superimposedly with a balanced sawtooth voltage of small
decreases rapidly. Often the " Dip" more or less only can be suspected then amplitude. The result is a balanced frequency modulation (sweeping) of the
it can be seen. VFO around the carrier mid frequency. The chosen frequency shift is
aproximately +/- 0.2% of the current oscillator frequency. The sweep rate is
The "super dip metre" developed by the author avoids problems mentioned approx. 400 Hz. The VFO frequency if couppled to an object in resonance
above with the following trick : "sweeps" over the resonating curve of the examinee now.

The same is carried out manually by the

DK1HE - " Superdipper " DipIt operator at conventional dip metres
with the tuning knob but muchl slower
!!
Device Under Test Oscillator AM-Demodulation AF-Amplifier
The answer of the VFO is a 400 Hz
amplitude modulation of its HF output
voltage due to fact, that the examinee
400Hz
sucks more or less energie from the VFO
40dB depending on the frequency beeing
more or less in resonance or not. The
modulation depth is deeper, the more
Resonance Detection by LED exact the oscillator mid frequency
Adder agrees with the resonance maximum of
+8V the examinee or the more strongly the
coupling is carried out. A demodulator
+8V circuit stage with a capacitive coupling
22.09.2005 SOLF DK1HE separates the 400 Hz AC signal. . The
Frequency Tuning Change: DL2FI Mai 14.2006 Super Dippers display consists of a
simple AF Amplifier which amplifies the
400 Hz signal by about 40 dB supplies
nad a LED which lightens up
proportional to the signal strength
after rectification. Amplitude changes
November 22.2007

Sweep Linearisation can be recognized very cleanly since

the light-emitting diode is fed with
400Hz 400 Hz half waves. Alternativ of course
a needle meter can be used if wanted.
Sawtooth Generator 3
 In the measurement procedure described above the absolute HF level of the inducation amplifier by C2 / S1.
the oscillator plays a subordinate role (only the modulation contents are
judged). A Potentiometer for the adjusting of the sensitivity can therefore 2. Frequency sweep generator:
be dropped.
The timer circuit IC3 forms an R/C oscillator with a balanced sawtooth
Since one can almost arbitrarily amplify the demodulated 400 Hz signal as output voltage. The generated frequency is approximately 400 Hz. The
high as you want, this new has Dipmeter design offers a significantly output signal is divided by R19/R20 the an optiml vaue for the frequency
higher sensitivity than all previous equipment. The coupling to the swwp operation. IC2a works as adding stage. The sawtooth voltage coupled
examining object can be carried out extremely loose what is of benefit to a by C17 is added to the stabilized DC
Wobbler Ein/Aus
high reading accuracy. ( PA coils still can be dipped cleanly from a coupled by R18. At the output of the
distance of > 20 cm giving a chance to measure them without any St3/2
OpAmp now we have an 8V DC with a

R21
10k
S2
C20
detuning. St3/1
balancedly superimposed sawtooth.

150k
R22
T5 100n
+8V
This is feed into tuning Pot P5. R45
BC546B
7 8 4

6 3

Wiring description of the individual circuit stages: defines the VFO-tuning range. C38-
2
IC3
555
1 5

R46 and P5 form a voltage divider for

0,015µF
R18

R19
47k

33k
C19
C17
3

1. VFO: IC2a 2
0,047µF
Group 2
the sawtooth quota of the tuning

R20
470R
TL082
Sägezahnoszillator
+8V
voltage. They also linearize the Sawtooth Oscillator
~400Hz
A Hartley oscillator built up with JFet T1 forms the heart of the circuit. The unlinear Voltage/Capacity curve of
oscillator circuit consists of the the diodesD1/D2 especially in the lower voltage range. By this methode an
L1 amd tuning diodes D1-D2. almost constant sweep shift is obtained over the complete variation area.
Steckspule bzw. VHF/UHF-Modul

VFO+Demodulator
By means of the 10 turn Pot P5
Bu1
1k2
the oscillator frequency can 3. Indication amplifier:
4

T1
R2 varied around by about an
C1 octave. By choice of the plug in St1/3
Dipper The demodulated 400 Hz signal coming from T1 via selector switch S1
3 100p
C2 coil a total frequency range of reaches the input of the AF amplifier IC1a. By means of R12-R13 the gain is
33n

D1
BB112

L1
1 approx. 1 MHz to 42 MHz is St1/2
Absorber set to 40 dB. Capacitor C15
+10V
covered in 5 steps. D3 has two Display Amplifier serves to isolate the DC
BB112

2 D3
100k
R1

functions: 1. it serves for the quota of the signal voltage.

1N4148

10k 1M

R15
D2

390R
5 automatic bias voltage R12 R13 Byt P2 the DC quiescent
1 generation of T1 an d2. it works C15
0,1µF
T4 output level of the OPs is
2 4
as AM demodulator. R2-C2 form St1/1
1
1k8 adjusted so that the light-
10k IC1a R14
2 68k a AF lowpass filter with a 8 100n
emitting diode D12
P5 R3 S1 3
cutoff frequency of about 4 (resonance display) just

November 22.2007
47µF 3 C4 C3 Resonanz-
C38 P2
kHz.The demodulated 400 Hz AF starts "week glowing"

R16
4n7

27R
5k C16 Display
15p
Signal, which allready has been St2/2 without AC signal. The
R46

R45

+10V
2k7

6k8

R17

preamplified by T1 is coupled to circuit works in addition as

8k2

St2/1
D12
LED spec a rectifier at this operating
Frequ.-Einstellung
4
 point adjustment. At an available AC signal the positive half waves of the R28 the stage gain is adjusted to 20 dB. The transformer TR2 transforms the
OP output voltage cause a periodical current flow in the light-emitting dynamic Collector-Resistance of T6 to the system impedance of 50 ohms.
diode. The brightness is proportional to the signal amplitude. T4 serves for The amplified RF signal can be taken from the signal source output jack
the current load reduction of IC1a. R15 limits the diode current to about 20 Bu6 for individual applications.
mA.
To ensured a frequency range and frequency independent output level of
4. VFO buffer stage, Power Amplifier, Regulation Circuit Stage 7dBm the circuit around Transistor around T6 is designed as a "VCA"
Capacitor C3 couples the low harmonic VFO signal directly to the following (Voltage controlled amplifier). The actual RF output voltage at Bu6 is
JFET buffer stage T2. The RF Voltage at supplied about the decoupling resistor R29 to the peak voltage rectifier
Buffer
C5
the low-impedance source is feed into the
47n circuit D6-D7 and after filtering by means of C26-C27 as nominal "Ebit
T2
R5 +10V frequency counter module via connector
39R
Voltage" passed to the inverting inverting input of IC1b. The non inverting
Bu3 to to display the actual VFO Input is feed with a "Debit Voltage, controlled by variable Resistor P3. PIN-
100k
R4

frequency. It serves furthermore than as Diode D5 is the "setting device", together with R23 it forms an RF Voltage
390R

47nF
R6

C7

Local Oscillator (LO) signal for the beat divider, controlled by the Diode current.
frequency measurement. Impedance Example:
Frequ. Counter Bu 4 transformation is carried out by TR1 to if the rectified RF Voltage is smaller then the Level preadjusted by P3, the
the following output amplifier T6. By DC output of IC1b gets more positive. By means of R24 the current in Diode
means of the counter-coupling resistance D5 increases. This causes an increase of the dynamic resistance of D5. So
27R
the RF Voltage at R23 (Input of RF Amplifier) increases until the rectified
C22 C23
output equals th Value predefined by P3.
0,47µF

R47
100n

47n
TR2
1 3
C24 Is the level at Bu6 is too high, the "debit voltage" is higher then the "Ebit
RF-Amplifier 6 Bu6 +10V voltage". Now the output at IC1b decreases as well as the current in D5.
R27
3k9

2 4
T6 +7dBm Lower current in D5 causes higher dynamic resistance in D5, so the RF
D5 C21
TR1 7 St4/3 Voltage at T6 also will decrease until the inverting input meets the "Debit
BFR96S
3
BA479 47n
Ein
Voltage" again.
2 4 RF-Generator-
Output
560R
R23

R26

R28
68R

10R

5. Heterodyne Frequency Measurement:

47n

270R
R29

C8 S4
Aus

10n C25 St4/2 The "heterodyne frequency measuring instrument" fallen into oblivion long
R24
2k2

LM358 C27 C26 D7

7
6 AA118 ago is excellently suitable for the frequency measurement of small HF
47µF 47n
IC1b 5 AA118 Voltages in the µV area or to the telemetering of unknown signals over an
D6
aerial. Integrated in our SuperDipper you find a direct conversion mixer
R25
4k7

~0,7V DC
built up with the MOSFET-Tetrode T3. The signal voltage coming from the
November 22.2007

R30
RF Level 120k
input jack Bu5 reaches via adjustable reducer P1 the Gate 1 of the mixer
R31
33k

8V R32
33k
stage. The Lo signal coming from T6 is brought to the Gate 2. The
difference frequency relevant for the measuring is at the output of T3 with
Group 5 Power Output an assessment frequency range of 4 kHz of (Lowpassfilter R10-C12) at the
5
 Bu5
the RF signal to be measured is not frequency stable the Sweeper can be

100p
4 C9
switched on. In this case the now frequency modulated VFO vfo sweeps

100k
R9
C6
over a certain area of the drifting measuring frequency and the signal

33n
47n C12
1k 270R
maximum still can be recognized cleanly here too, provided that the
68R
R10 R11
R7
5 P1
C13
250R 0,22µF C14 frequency instability does not get greater than about 8 kHz.
T3 100µF

47n C11
HF-Abschwächer 7. Voltage Supply:

150R
+8V

R8
10µF
C10
Loudness Since a dip metre will be used only sporadically in the amateur radio
10k
practice and due to the known the self-discharge problem of modern high
Group 4 Directconversion
(Zerobeat Frequency Meter) P4 C36 St5/2

+8V +10V
disposal. The audio amplifier IC4 allows monitoring of th esignal signal to

47µH

180R
R36

100k
R38
Dr2 S3 Ein/Aus ON/OFF
be measured with headphone volume. If Input frequency and vfo frequency Dr3
D8
are almost all the same, you hear the so called "beat tone". If now vfo IC5
78LO8
R37
220uH T7 1k 100p St5/1
1N5817
frequency is carefully adjusted until the beat frequency is not loger audible C33
1µF 100uF
C37
100uF 8
(now "zerobeat" ), bith the measured frequency and the VFO frequency are BD137 +
C34 C35
exactly identical..
4x 1,5V AA
BC546B BC546B
During the measuring described above the Sweep-Generator must be turned

ZPD10
D9 9
-
off!

R39

1N4148
1k2
T8 T9 D10

6. Absorption Measurement:

If the operation style switch S1 is switched to position "absorber", the capacity NiMH accumulators we decided to use 4 of cheap AA- alkali
input of the indication amplifier is connected to the output of the direct manganese batteries which offer an operating voltage of 6 volts )? The
conversion mixer T3. In this mode the visual level, known of the Dipper internally required 10 volt supply Voltage we produce with a switching
gets effective in addition to the acoustic assessment of the signal. The transducer. T7 forms a flyback converter together with Dr2 and T9. C37-R38
amplitude of an HF Voltage fed in into jack Bu5 is announced by a determines the switching frequency. The transducer output voltage reaches
proportional brightness of D12 now. The vfo must be taken to "zerobeat" the Schottky switching diode D8 to the filter capacitor C35. The Z diode D9
with the frequency to be measured. The Attenuator P1 should be adjusted together with Transistor T8 are limiting the transducer Voltage to 10 volts .
so, that D12 never shines with full brightness since otherwise small The switching transducer works stable as long as the batterie voltage is

November 22.2007
amplitude changes of the signal voltage cannot be recognized cleanly. This higher then 4 volts, so the full capacity of the batteries ca be used.. The
measurement procedure is the more sensitive variant of the well known sieve Dr3-C34 reduces the residual ripple on the 10 volt supply Voltage, the
classic Absorbtion Measurement. With it transmitter oscillating circuits or following Voltage regulator IC5 provides the system with the stabilized 8V
Bandpassfilters behind TX mixers very easily can be tuned on maximum. If DC we need at some places.
6
 8. battery voltage control:

To get full control over the batterie status, a visual battery voltage
supervision was integrated into the SuperDipper. The Comperator IC2b
compares the voltage down shared about R40-R41 (4,4V) with the battery
+8V
voltage supplied by
Batteriespannungsüberwachung R43. If the actual
Batterie Voltage Control Voltage falls below the
R40

4.4 volt threshold, the

10k

D11 output from IC2b

R42
330k 1N4148 switches "high" and
5 4
680R
St6/1 the approaching end of
7
6
IC2b R44 LED the battery voltage
R41

100n
12k

8 D13 range signals the light-

C18
emitting diode D13.
3,3µF St6/2

+10V By means of D11-R42

C39 the Komparator gets a
R43
5k6

hysteresis what a
stable function ensures
also at battery Voltage
A following AM demodulation stage separates the the 400 Hz AC tone. The
display part of DipIt is a simple 40dB AF Amplifier, a rectifier and a
superbright LED.
Using this method, the only criteria of detecting resonant devices is the
AM-Modulation so the different Amplitude hight of the VFO depending on
its frequency is no longer a problem. That fact, that an AM signal can be
amplified very easy increases the sensitivity of the dipper dramatically.
Coupling between DipIt and DUT can be much looser then with any
conventional dipmeter, the dip is absolutely clearly.
November 22.2007

7
Beginning of the structure Building group 1, voltage supply [ ] R44 A/7 6 680R
[ ] C18 A/6 100nF
[ ] D11 A-B/7 1N4148 pay attention to situation of
the ring-stamp (cathode)
[ ] R43 A-B/7 5,6K
[ ] Dr3 A/7 220uH
[ ] Dr2 B/7 47uH
With the following Elko(electrolytic) be careful how they are installed. The
longer leg is the positive pole, the housing is marked on the side with the
minus connection mark.
[ ] C35 B/7 100uF rad. Elko
[ ] C33 A/7 1uF rad. Elko
[ ] C34 A-B/7 100uF rad Elko
[ ] C36 B/7 100uF rad Elko
[ ] R40 B/6 10K 1%
[ ] R41 B/6 12K 1%
[ ] R42 B/6-7 330K
[ ] D8 B/7 1N5817
[ ] D9 B/7 ZPD10
[ ] St5 B-C/7 Patch cord receptacle 2-pol, tongue inward!
[ ] R37 C/7 1K
[ ] R36 C/7 180R
[ ] C37 C/7 100pF
[ ] R38 C/7 100K
[ ] D10 C/7 1N4148 pay attention to situation of the tax
stamp
[ ] R39 C/7 1,2K
Transistors and ICs are more or less sensitive to ESD. It is however a good
exercise with semiconductors to pay attention and adhere to the ESD safety
precautions. Use a ESD bracelet or at least touch a bare, grounded surface,
before you touch the transistors.
[ ] T8 C/7 BC546B
[ ] T9 C/7 BC546B

November 22.2007
The BD137 is inserted in such a way that the marked side is turned away
from the choke/coil and points to the edge of the board.
[ ] T7 B-C/7 BD135 (oder BD137, BD139)
Beginning here, there are ESD sensitive parts used. [ ] IC5 A/7 78L08 TO92
[ ] St6 A/7 CHANGE!!! ST6 do not install!!! Pay attention to the correct installation of IC 2. The notch marks pin 1 (to
8
 the left of the notch) in the bill of material circuit board. The height of the connector assembly will interfere with
[ ] IC2 A-B/6 TL082 DIL8 closing the case later on.

On the lower surface below the IC2 a tantalum capacitor is soldered. The Test of the building group: Connect the battery holder to the PLUS and
POSITIVE side is marked by a bar with this design (SMD Baugr. B). The bar MINUS battery connections (see bill of material P. 16.)
is clearly seen towards the diode and towards the outside edge of the pc
CAUTION when using a power supply instead of the batteries!!! Do not
forget to adjust to 6V! The transducer does not easily handle 35V from 13V
supply and the transistors survive, at 10V it hangs. With laboratory power
supply the current limiting may not be adjusted low enough and since the
transducer pulls a high starting current damage may occur before the cur-
rent limiting responds.
Some Batteries and power supplies have very low internal resistance. This
may cause the oscillator not so start. To prevent this situation please add a
1 Ohm/1Watt resistor into the +6V power line. Starting September 22. this
resistor is included in the kit (as small as the standard resistors, green
board. body).
C39 3,3 uF 16V Tantalum SMD

Now socket Bu4 is still missing, to which the display is attached later. It is Attach switch S3 to St5 — Switch the switch on. Measure the voltage at
put on the component side and soldered on the solder side. We use 2 fema- points named X against ground. The 8 and 10V voltages must be achieved.
le sockets, which we break-out carefully from the long socket strip. If both voltages are present, you can continue on with the construction of
the building group 2.
[ ] BU 4 Contact Strip 2 Pol. A-B/3

For building group 1 now install the LED for the battery monitoring and the
switch for the battery.
Take 2 pieces of cable from the hardware parts for the system plug connec-
tors and solder a switch to the wire ends of
one cable and the LED to the other cable
paying attention to the LED polarity, the
short leg is the cathode, it is goes to the
plug pin 2.
November 22.2007

[ ] D13 LED at for cables St6

[ ] S3 Switch S3 at for cables St 5

Do not install/solder ST6 connector to the

9
Building group 2, relaxation oscillator [ ] IC3 C/6 ICM7555 DIL8 w/ PIN 1 Pay attention to the
notch
Connect.switch S2 with cable for plug St3
Solder switch 1xEIN on at cable end.
[ ] S2

Test Building group 2

Attach Batteries
Switch Batteries ON
S2 is ON

At IC3 PIN 6 temporarily attach a small capacitor in the nF range to feed a

pair of headphones. Expect a signal of approximately 400 cycles per second
to be heard. Connect the cap to the emiter of T5, the same signal should be
heard a little bit quieter.

If that is ok, then proceed with building group 3

[ ] R18 B/6 47K

[ ] C17 C6/7 0,047 uF foil capacitor (red)
[ ] St3 B-C/6 2-pole Patch cord receptacle pay attention to
orientation of plug
[ ] R19 C/6 33K
[ ] R20 C/7 470R
[ ] R21 C/6 10K

November 22.2007
[ ] R22 C/6 150K
[ ] C19 C/6 0,015 uF foil capacitor (red)
[ ] C20 C-6/7 100nF
[ ] T5 C.6/7 BC546B

10
 Building group 3, oscillator, indicator amplifier [ ] C1 B/1-2 100pF
[ ] R1 C/2 100K
[ ] D3 C/2 1N4148

[ ] C2 C/2 33nF
[ ] R2 C/1-2 1,2K
[ ] C14 C/1 100uF, pay attention to polarity !
[ ] R11 C/2-3 270 R

The following two diodes have TO92 housings and 2 legs. The third leg is
rudimentarily present and holds the danger to cause a short-circuit between
the two legs of the diode. With this in mind, be very cautious to mount the
legs so they do not contact each other or touch the wrong circuit board
pads.

[ ] D1 B/2 BB112
[ ] D2 B/2 BB112
[ ] T1 C/2 BF244A

[ ] B-C/1 Bu1 print DIN socket

Make sure that the socket is completely flat on the circuit board. Solder
only a single socket pin, check the socket position, then solder a second
pin and check again. If the socket sits really flat, then solder the remaining
pins
November 22.2007

[ ] C4 B/1 4,7nF
[] B/1 Solder pin at Position 2
[ ] R3 B/1-2 68K
[ ] C3 B/2 15pF
11
 [ ] IC1 A-B/4-5 LM358 observe pin
1 (notch) position
[ ] A/6 Soldering pin Position 1
[ ] A/6 R45 6,8K
[ ] A/6 R46 2,7K
[ ] A/6 C38 47uF
[ ] A/6 Soldering pin on Position 3

Switch S 1 must be soldered to the 3 wires

the ST1 plug.
[ ] S1 switch

[ ] Solder three wires, each about 10cm long to the three connections of
the 10-turn potentiometer. Solder one of the solder nails sleeves to the end
of any wire.
[ ] Connect the the solderpin sleeves to the responding solder pins.
Attention We get different Pot dypes from the supplier, the numbers on the
pot do not allways correspond to the solder PIN number. Pin number 2
MUST be connect to the middle connector (variable) of the pot.
[ ] P5 10K 10-Gang-Pot

Solder the 5mm red LED to the two wire ends of the plug St2. The cathode
(short leg) attaches to pin 2
[ ] D12LED
In order to be able to test the building group 3, only one of the 5 Dipper
coils must be made. The Dipmeter coil uses a 15.5mm plastic (water) pipe
as it’s coil form. The pipe diameter can differ from make to make and the
[ ] C16 A/4-5 100nF
dielectric constant of the spool has a certain influence particularly on the
[ ] St1 B/4 Patch cord, pay attention to tongue
higher frequencies. The data listed (frequency range) is approximate and
[ ] C15 B/4 0,1uF insert flat to the pc board!!
may vary somewhat. The number of the coils may not be sufficient to
[ ] R12 B/4 10K
completely cover entire frequency range. However, with use of the DipIt
[ ] R13 B/5 1M
frequency counter this will not be a problem.
[ ] R14 B/5 1,8K
[ ] R15 B/5-6 390R

November 22.2007
When making the coils measure from the lateral-end of the 15mm coil form
[ ] R17 B/6 8,2K
to where you will drill the holes for the winding wire. (see Dimensional
[ ] R16 B-C/5-6 27R standing
drawing).
[ ] ST2 B-C/6 System- Patch cord
[ ] P2 B/5 Trimpot PT6 5K
[ ] T4 B/5-6 BC546B
12
 Type 2 has a inner diameter which is a little bit smaller then the diameter of
the black socket. One can gently heat up the pipe with a heat gun or a hair
dryer. The plug base can now be pushed into the pipe up to chamfers. After
the pipe sits and cools off the plug base fit will be quite snug, we
recommend, nevertheless, the additional use of some type of adhesive. Now
take the Dipmeter with the new coil installed and with the help of a receiver
tune and listen for a signal. It should lie somewhere between 5 and 10 MHz
and you should hear a very strong signal. If you found it, then the
oscillator swings. Put the coil aside, it will be completed and aligned after
the Dipper is completely built. Assemble now the counter and the indicator
boards. You will repeat this test again with the added counter, after com-
pleting building group 4.

Spule=coil bereich=range stecker=plug

The enameled wire should be wound evenly
with each turn close to the next turn. The
wire ends should be kept short then soldered
to the pins of the plug base. The drawing here
shows the soldering pins of the plugs as seen
from the solder side. These plugs are part the
5 pin male connectors provided in the kit.
You may discard the metal shields and molded
covers from these connectors.

Attach the pipe after soldering the base plug. Two differently methods can
be used:
1. The plug base fits quite snuggly up to chamfers into the pipe, but
one can press it in with the hand without tools. If the pipe sits straight on
the base, then the connection can be durably fastened later with some of
the two-component adhesives(epoxy).
Actualy we ship two different types of pibes due to some shipment pro-
November 22.2007

blems of our supplier.

Type 1 has an inner diameter which is a little wider then the black socket.
Before glueing the black socket into it, adjust it with 3 small pieces of
wood or something similar to sit in the middle of the pipe´s diameter. Glue
it to its position with epoxy.
13
Building group 4 Direct Conversion part

[ ] R34 B/5 12R

[ ] R33 C/4-5 100R
[ ] R35 C/5 4,7R
[ ] P4 C/4 10K
[ ] C30 C/4-5 0.04 uF Foil condenser (red)
[ ] C31 C/5 47 uF rad. Elko
[ ] C29 C/5 10 uF rad. Elko
[ ] R7 A/1 68R
[ ] C28 C/5 10 uF rad. Elko
[ ] C9 A/1 47nF
[ ] C32 B-C/5 100 uF rad Elko
[ ] C11 A-B/1 10 uF rad. Elko

November 22.2007
[ ] Bu2 C/5-6 !! Change: Socket do not install!!!
[ ] R8 B/1 150R
[ ] IC4 C/4-5 LM386N-1
[ ] C10 A-B/1 47nF
[ ] C12 B/1 33nF
[ ] R9 A-B/2 100K

14
 [ ] P1 A/1-2 250R the winding somewhat loose. Pass the wire
[ ] C6 B/2 100pF through the top hole (from left to
[ ] C5 B/2 47nF right)and down through the lower hole
[ ] R4 B-C/2 100K (right to left) as shown on the left. This is
[ ] R5 B/2-3 39R the first turn.
[ ] R6 B/3 390R
[ ] C7 B/3 47nF
[ ] R10 C/2 1K
[ ] C13 C/2-3 0 ,22uF Foil capacitor (red) lying flat
[ ] Bu3 A/3 2 pole female socket, which we break-out Now continue the wind back up to and
carefully from the long socket strip. Solder from the solder side. through the top hole (right to left) then
Now the dual gate MOS T3. The BF981 is very down again and through the lower hole
sensitively to electrostatics, thus consider ESD (right to left) Turn 2 is finished. Do not
Measures! The design shows those Arrangement pull the wire too much over the edges,
of the Pins as one see sees,from above the dual the lacquer finish on the wire is very
gate MOSFET. Notice the inscription and the thin.. Contine winding in this fashion
position of the DRAIN Connection The picture with turn three, four, five and six and this
here clearly shows pin designations. the case of completes the primary winding.
the BCR all 4 connections are marked. Bend all 4
Pins carefully by 90 degrees to the rear away
(away from the inscription), set it to its place
and solder it. Still the secondary winding is missing. The secondary winding receives 3
turns from 0,3mm CuL. So that the installation is simpler, our technical
[ ] T3 A-B/1-2 BF981 designer put on TR1 in such a way that the secondary winding is attached
[ ] T2 B/2 BF246A exactly on the side lying opposite. Take a 12 cm long piece the 0,3mm of
[] A/1 Soldering pin up Position 4 and 5 wire, and lead it carefully from
right after left by the upper
So that building group 4 functions correctly, the transducer TR1 must be hole and from left to right by
inserted. that lower hole again back. The
first turn is finished. Repeat
Winding guidance transducer TR1 this step for turn 2 and again
Transformer 1 is wound on a double hole core, which among us we jokingly for Turn 3. Remember to keep
call pig nose. Put the pig nose down in such a way in front of you that the the windings somewhat loose.
November 22.2007

two holes run from left to right. Mark the left side with Nailpolish or other
coloured laquer , so that you can again recognize this side later, this side In the next step it is important
will become the primary Coil. TR 1 receives primarily 6 Turns 0,2mm CuL to completely remove the
and secondarily 3 Turns 0,3mm CuL. Cut off a 25cm long piece of that 0.2 lacquer insulation from the wire ends. That can be done best with „the
mm wire and thread it through the Pig nose, as shown in the picture. Keep Blob“ method. The lacquer decomposes with 350 degrees C soldering iron
15
temperature. With the Blob method, bring the wire into a thick drop of housing. The housings of this series will not have a hole
melted tin solder on the soldering iron point. Start directly behind the in the side panel. Connect the wires to BOTH points
ferrite body, keep the wire inside the hot Blob on the soldering point and marked „X“ and GND as shown in the layout plan in the
slowly move the wire to its end. This method eliminates the back and forth picture. Use two twisted wires.
scrape to remove the lacquer. One recognizes the beginning of the decom-
position process by the ascending Smoke. In this phase move the soldering
iron slowly toward on the wire end. As the lacquer burns off, the wire tins
at the same time. Use a magnifying glass to determine whether the wire is
properly tinned.

The transformer can be now installed. Install it exactly as shown, here and
drawn on the pcb. Thread those four wire ends into the holes 1 to 4. Pull Test building group 4: Attach the battery at the Dipper. Put the coil into
the transformer by the wires taut carefully against the the socket for the coil. Put the 10 turn potentiometer to his place, switch
board. Check whether with all four tinned wires sit in on the Dipper. Switch the oscillator off. Switch the Dipper to absorbers.
place within the plated-through holes. The transformer Connect an antenna to Bu5. Plug in Stereo headphones at BU2 set the
should now lie symmetrically as possible between the Volume Pot to the clockwise direction. Place the Attenuation Pot P4 in
4 holes. If everything is correct, then solder the four center position.
wire ends as you hold the transformer in place. After
completion of the soldering procedure ensure the If you turn volume potentiometer up now slowly, then you should hear
transformer lies flat against the board. If it is loose some broadcasting stations. The Dipper works now like a direct superhetero-
heat the four soldered connections in succession and dyne receiver on short wave within the range of the coil being used. Natu-
pull the wires taut. rally it does not have a much selection, and it you will hear overlapping
signals. In our attempts with DipIt prototypes and using a Z-match we
[] TR1 B/4 mini double hole core primary heard CW and SSB QSOs without problems.
6 Wdg 0,2mm CuL secondary 3 turns 0,3mm CuL

For the preparation of the building group test solder a 5cm long piece of
RG174 coax cable on to the BNC socket BU5. To the other end of the coax
cable solder a 2-plug female socket for connection to soldering pins 4 and
5 at (A/1) pin 5 is ground, pin 4 is the center conductor.

[] Bu5 BNC

November 22.2007
The Stereo socket was originally to be installed on the circuit board. After
production of the Dipper cases we discovered however our final design
wasn’t quite right. We did ourselves a favor and moved the socket off board.
The Stereo socket now becomes connected by wires to the original circuit
board location right beside the battery holder at the end of the dipper
16
 Frequency counter and announcement [ ] R11 560R lying
[ ] C11 4 7 nF (473)
[ ] C10 10 nF (103)
[ ] R12 33k (possibly later up T3 UCE 2,5V adjust)
[ ] C9 47nF (473)
[ ] R13 390R
[ ] R14 820R
[ ] C7 47nF
[ ] C6 1uF Elko, respect polarity long leg = PLUS
[ ] C5 1uF Elko, pay attention to polarity
[ ] C8 1nF (102)
[ ] R15 100k
[ ] C2 56pF

[ ] Q1 20 MHz quartz. Place two cut off resistor leads under the crystal to
support the assembly a small distance up from the circuit board. This space
will prevent the tin solder from creating a short-circuit between crystal and
printed circuit board. Do not forget to pull the wires out again after solde-
Put the plate down before you in such a way, as seen on the design, so that ring.
you can always orient yourself. Do not insert the contact strips yet, you
some characteristics to consider. Solder R 9 as the first the resistance. You [ ] C3 100nF (104)
see it here on the design (as writing in a mirror) drawn inside the outline [ ] C1 47pF (47p, 47j)
of IC 1, that means, it belongs on the solder side of the plate. [ ] C4 30pF foil trimmer

[ ] R9 10k Install on the solder side and solder on the component side. Now the base for the microprocessor. Make sure that the notch in the base
Cut the Pins off after soldering very close to the soldering plates. The is oriented in such a way, as seen in the design.
remaining parts are installed normally from the component side. Begin in [ ] Socket IC1
the left, upper corner. All parts must be installed close to the board other-
wise the will be problems later when plugging the boards together. Sectional drawing, part facing downward, seen by the broadside
2x4 link female
[ ] D4 1N4148 - It makes sure that the Band mark ( 1x2 ink male Connection sockets are installed on both sides of the display
cathode end) is oriented as in the design. board.. They must make the connection to both the motherboard and to the
[ ] D2 1N4148 Upright. With standing diodes the dis-
November 22.2007

band stamp shows the cathode upward and the diode Schnittzeichnung, Bauteile nach unten ,von der Breitseite gesehen
body is mounted where the circle is drawn..
[ ] D1 1N4148 standing, exactly the same as D2 2x4 Verbinder weiblich

[ ] D3 1N4148 standing, the same as D2/D3

[ ] R10 10k install, likewise standing IC1
1x2 Verbinder männlich

17
play board. It best done if one builds, aligns completely the two boards can test everything together. Here there are only few parts. Begin with the
together using the plug connectors and enclosed spacers before soldering. resistances. The component side has the label DL4YHF :
For the connection to the display we take the female links.
Install counter plate one Since hanging, thus with the parts to the Haup- [ ] R1 560R [ ] R2 560R
platine showing the. The 1x5 and 2x4 link are installed on the solder side [ ] R3 560R [ ] R4 560R
and soldered on the component side. Make sure that the links stand as [ ] R5 560R [ ] R6 560R
perpendicular to the circuit board as possible. Solder only one pin, align [ ] R7 560R [ ] R8 560R
the group and then solder the remainder.
Solder on the component side: Now the 5 pieces of seven segment displays. Do not insert them upside
[ ] Link 5.4.3.2.1 (female) [ ] link D, DP, C.E (female) down. You will see a decimal point on the bottom right of each announce-
[ ] link F, G, A, B (female) ment. Place a display unit into the circuit board, as shown in the design.
Press the announcement firmly against the circuit board while soldering
Now the two links to the motherboard. They are installed on the component and solder only two pins diagonally opposite each other. Check whether the
side and soldered on the solder side. Pay attention again to install it exact- announcement really mounted flat, and correct if necessary, by re-heating
ly perpendicularly. the two soldered connections. Then solder the remaining pins. Proceed with
[ ] Link Ub (male) [ ] link RF-IN (male) all 5 diplay units in accordance with this method.

Install the remaining semiconductors: [ ] DSP1

[ ] T1 BC546B [ ] T2 BF2546A [ ] T3 BF311 [ ] DSP2
The Voltage Control IC2 = 7805 generally speaking TO220 housing. Now the [ ] DSP3
Processor can be put into the base. Remember, this part is very sensitive to [ ] DSP4
electrostatics, pay attention to the ESD rules. [ ] PIC 16F628 [ ] DSP5

That was the counter, now the display board must be soldered before we Now the links. All three connector groups are installed on the solder side
and soldered on the component side. Since they connect to the counter
board and you installed female links there, logically you must use now use
male connectors. Again make sure that they sit accurately perpendicular.

[ ] Link 5 pin (male)

[ ] Link 4 pin (male)
[ ] Link 4 PIN (male)

You can temporarily put the three plates together now. The motherboard on

November 22.2007
the bottom, whereupon the counter board (parts side towards the mother-
board) and on the top the display board (announcements upward). If you
repeat the building group 3 test now, you will have a digital frequency
display.

18
 [ ] D6 A5 AA143, GA103 or
similar.
With standing diodes always the Cathode (banded end
upward) and put the body where the circle is drawn in
the plan.
[ ] C25 A/5 10nF
[ ] C24 A/5-6 47nF
[ ] C27 A/5 47¼F
[ ] St4 A/6 System- Patch
cord
[ ] R30 A/5-6 120K
[ ] C26 A/5 47n
[ ] R31 B/5 33K
[ ] P3 B/5 5K Trimmpot
[ ] R32 B/6 33K

Now transformer TR2. It is wound exactly the same and

inserted, as it was described with Tr1.
Building group 5
[ ] R26 A/3 560R [ ] TR2 A/4-5 mini double hole core primary 6
[ ] R23 A/3 68R Wdg 0,2mm CuL secondary 3 turns 0,3mm CuL
[ ] R28 A/4 10R Now transistor T6. This is very sensitive to ESD.
The only small SMD part, installs in the middle in the field. Please solder Insert T6 so that you can see the writing from
only on the right side (left side unsoldered), so that the hole for T6 is not above and carefully bend the three Pins down-
clogged by solder tin. ward perpendicularly. Set T6 into the three
[ ] R27 A/4 3,9K holes, the writing must remain readable otherwi-
[ ] C22 A/4 0,47uF Foil condenser se the transistor is mounted backwards.
[ ] C23 A/4 100nF
[ ] C21 A/3-4 47nF [ ] T6 A/4 BFR96S
[ ] D5 A/4 BA479 Now do not forget, to solder the left side of the
[ ] C8 B/4 47nF SMD transistor R28!!!!
[ ] R24 B/4 2,2K Install the two soldering nails in positions 6/7
[ ] R25 B/4 4,7K [ ] Soldering nail A/5 Position 6
November 22.2007

[ ] R29 A/5 270R [ ] Soldering nail A/5 Position 7

[ ] R47 A/5 27R
Temporarily solder two wires to ST4 from the switch S4. Solder a 5cm long
On the board with DR1, designates replacement)
piece of coax cable to a Phono socket. Solder the other end to the solde-
[ ] D7 A/5 AA143, GA103 or similar.
Caution, the glass body breaks easily! ring nails at positions 6 (center conductor) and 7 (ground).
19
Test building group 5

Attach the battery and all switches used so far to DipIt. Put the frequency
coil already manufactured into the base. Connect Bu6 (HF generator output)
to a dummy load (can be small dummy load as we produce only QRPppp,
7dBm).

Switch the Dipper on.

Switch the relaxation oscillator out (S2)
Switch the mode selectors to „Dipper „

Measure with a high impedance voltmeter the DC voltage at IC1 pin 5 and
adjust it with the trim potentiometer P3 to as close as possible to 700mV.
(For this manual: exact value still to be determined). Thus the output of
the generator is adjusted to +7dBm according to 500mV EFF HF at 50 ohms.
(D6/D7/C26/C27 form a HF probe, which changes the HF voltage into DC
voltage as it heads to the automatic control loop, which keeps power
output constant.)
Alignment work:

There are actually only three places, which can be adjusted:

1. P2 in the indicator amplifiers building group. P2 is adjusted in such a

way that the breakdown voltage of the diode without control is reached by
the Dipper. In addition the coil is taken off and P2 adjusted in such a way
that the LED just „visibly glows“. The whole naturally in position „Dipper“
and „Oscillator“

2. The Dipper With a counter it does not depend on a few Hertz. One can
adjust the indicated frequency by means of the trimmer C4 on the counter
board in comparison to a reliable external frequency source

3. The +7dBm amplifier. The power output of the amplifier is limited using

November 22.2007
the trim potentiometer P3, sees accompanying description.

4. For sensitivity increase the oscillator can be increased somewhat, if R15

is made smaller on by approximately15kOhm. . It is enough to solder a 27k
resistance parallel to R19.
20
 Lges= 32mm/A1= 2mm/A2= 10mm Total total: 5 Wdg 0.5 mm of CuL, tap
Production and calibration of the coil spool.
with 2. Spread the turns to result in a max.-upper frequency of approx. 40
The measuring rangei is overlapping, starting with low frequency with coil
MHz. Measure this with the Dipmeter counter.
1 and continues upward. You hav already manufactured coil 3. The Dipme-
ter coil uses a 15.5mm plastic (water) pipe as it’s coil form. The pipe dia-
meter can differ from make to make and the dielectric constant of the spool
has a certain influence particularly on the higher frequencies. The data
listed (frequency range) is approximate and may vary somewhat. The num-
ber of the coils may not be sufficient to completely cover entire frequency
Reel 2:9,45 MHz-19,4MHz
range. However, with use of the DipIt frequency counter this will not be a
problem.

After completion of the coil, coat the coil with a thin coat from eagle owl
pluses or similar adhesive to protect against environmental influences. The
plug is stuck into the pipe and slid up to chamfers.

One can gently heat up the pipe with a heat gun or a hair dryer. The plug
base can now be pushed into the pipe up to chamfers. After the pipe sits
and cools off the plug base fit will be quite snug, we recommend, neverthe-
less, the additional use of some type of adhesive.

Reel 1:19 MHz-40MHz

Lges= 34mm/A1= 2mm/A2= 8mm

Total total: 12 Wdg 0,5mm CuL, tap with 2.
Spread the turns of the cold end. The turns must be spread in such a way
that the highest adjustable frequency lies somewhat higher than the lowest
frequency of coil 1.
November 22.2007

21
Reel 3:4,65 MHz-9,73MHz le. Always remember: the more strongly the item under test is loaded, all
Lges= 35mm/A1= 2mm/A2= 10mm the more strongly it changes its resonant frequency, all the more wrongly is
Total: 24 Wdg 0,3mm CuL, tap with 5. Turn of the cold end our result of measurement.
The turns must be spread in such a way that the highest adjustable fre-
quency lies somewhat more highly, as the lowest adjustable frequency of Reel 5:1,25 MHz-2,56MHz
coil 2.
Lges= 35mm/A1= 2mm/A2= 11mm

Total total: 95 Wdg 0,1mm CuL, tap with 19.

Turn of the cold end Who would like itself to manufacture a coil for the old
ZF 455 kHz, accordingly many turns on a further spool winding must. Re-
member, no ferrite use. The coil may be wound also 2-lagig.

Coil 4 and 5 are wound in the same manner, we did not not make drawing
for coils 4 and 5 because it wasn’t clear due to the high numbers of turns.

Reel 4: 2,44 MHz-5.05MHz

Lges= 45mm/A1= 4,5mm/A2= 23mm

Total total: 62 Wdg 0,3mm CuL, tap with 12. Turn of the cold end.
People have asked us why we do not us a coil with ferrite core, which
would lower the number of turns dramatically. The answer: we wanted to

November 22.2007
build here a high-quality measuring instrument useful to us. A coil with
ferrite core would bundle the lines of flux strongly inside the coil and is
exactly that an effect, which we can need with a Dipper in no case. With an
air core the lines of flux spread unrestrainedly outward, which makes it
substantially more sensitive and thus make unloaded measurements possib-
22
 Steckspule bzw. VHF/UHF-Modul
+10V Wobbler Ein/Aus
VFO+Demodulator Display Amplifier
Bu1
10k 1M

R15
1k2

390R
4
R2 Us R12 R13 St3/2

R21
10k
T1 C15 S2
T4
St1/3 0,1µF 2 4 C20
C1 Dipper
St1/1 1k8
3 100p 1
IC1a R14
C2 St3/1

150k
R22
T5 100n
8 100n

33n
D1 S1 3

BB112
L1 Absorber +8V
1 St1/2 Resonanz- 7 8 4
P2

R16
27R
5k C16 Display BC546B
6 3
BB112

2 D3 IC3
100k
R1
St2/2
+10V

1N4148
555
2

R17
8k2
D2 1 5

0,015µF
R18

R19
5

47k

33k
St2/1
D12 C19
Group 3 Ocillator LED spec
C17 +10V
3
1 zum Frequ.-Zähler
IC2a 0,047µF
Group 2 Bu3
2
Sägezahnoszillator

R20
470R
10k TL082
Buffer +8V Sawtooth Oscillator
2 68k 47n
P5 R3 C5 ~400Hz
T2
C3 C22 C23 27R +8V
47µF 3 C4 R5 +10V Batteriespannungsüberwachung
C38

0,47µF
R47

100n
39R
4n7

47n
TR2 C24 Batterie Voltage Control
15p

R40
R46

R45

10k
1 3
100k
2k7

6k8

R4

Bu6 +10V
RF-Amplifier 6

R27
D11

3k9
2 4
390R

47nF

+7dBm
R6

C7

T6 R42
330k 1N4148
D5 C21
TR1 7 St4/3 5 4 St6/1
Frequ.-Einstellung BFR96S 680R
3 7
BA479 47n 6
IC2b R44 LED
Ein

R41
2 4 RF-Generator- 100n

12k
8 D13
Frequ. Counter Bu 4 Output

560R
R23

R26

R28
68R

10R
47n

270R
R29
C8 S4
Aus C18
3,3µF St6/2

10n C25 St4/2

+10V
R24
2k2

LM358 C27 C26 D7 C39 DC/DC Wandler

6 AA118

R43
DC/DC Converter

5k6
Bu5
100p

C9 7 47µF 47n 100µ

4 IC1b 5 AA118 C36
100k

St5/2
R9

C6 D6
33n

R25
4k7

47n C12
1k 270R
~0,7V DC

47µH
68R

R10 R11
R7

R30

180R
R36
P1

100k
R38
5 C13 RF Level +8V +10V S3 Ein/Aus ON/OFF
120k Dr2
0,22µF C14 D8
250R Group 5 Power Output
R31

Dr3
33k

T3 100µF 8V R32 IC5 R37

47n C11 33k 78LO8 220uH
HF-Abschwächer P3 1N5817 T7 1k 100p St5/1
150R

+8V C33
R8

1µF
C37
100uF 100uF 8
C10
10µF
C28 BD137 +
100R

C34 C35
R33

Loudness R34 +10V

10µF 100µF
10k 4x 1,5V AA
Group 4 Directconversion C32 BC546B BC546B
Bu2

ZPD10
6
November 22.2007

P4 C31 -
(Zerobeat Frequency Meter) 5 D9 9
IC4

R39

1N4148
1k2
T8 T9 D10
47µF
3 C30
7
0,047µ
4
C29
R35
4R7

10µF
NF-Verstärker
AF Amp
Group1 Stromversorgung / Powersupply
23
24

November 22.2007
 November 22.2007

25
26

November 22.2007
 November 22.2007

27
 +7dBm of amplifier. The housing is bolted with the two pedestals. The
At the battery support attach the ground to screw. For the sake of insula- ground side of the pedestal for the side with the battery support points to
ting use tape or a piece of pasteboard(cardboard), it could otherwise Short- the batteries.
circuit with the housing, the same is also recommended with the jack Calibration of the +7dBm of amplifier. The amplifier can be calibrated
headset-phone and the screw in the thread block against the battery. very exact by its inserted HF probe and the rule loop. Switch the Oscillator
Because of the housing tolerances the thread block presses the edge on the off. Terminate the HF output with 50 ohms. If you do not have QRP dummy
battery it’s recommended the thread block edge be pushed diagonally load (e.g. the thermal wattmeter), then use a non-wirewound (carbon) 50
ohms resistor. Switch on the HF amplifier. DC voltage measures at IC 1 pin 7
Install the first the circuit borad into the housing. Use for it the 5mm and adjust it with the trimmer P3 to exactly xxx millivolts. At the output of
spacer. The battery support comes into the housing bowl at the lower end the Dipmeter now a very exactly +7dBm lines up.
of the circuit board. Connect the red wire of the tie-clip with pin 8 and the P2 in the display amplifiers building group. P2 is adjusted in such a way
black wire of the tie-clip with pin 9 of the circuit board (take in addition that the breakdown voltage of the diode without control is reached by the
ever one of the provided Steckschuhe) Dipper. In addition the coil is taken off and P2 adjusted in such a way that
the LED just „visibly glows „. The same in position „Dipper „and „Oscillator“
Connect a 1xUM switch with the help of to three-wire cables/plug combina- Attitude of the counter: With a Dipper it does not depend on a few Hertz.
tion with St1. The switch is S1, it switches between Dipper/absorber One can adjust the indicated frequency by means of the trimmer C4 on the
counter board in comparison to a reliable external frequency source.
Connect a 1xUM switch with the help of to two-wire cables/plug combinati-
on with St3. The switch is S2, for the Oscillator. If you already know how to use a Dipmeter, then you can now proceed. If
Connect a 1xUM switch with the help of to two-wire cables/plug combinati- not, then look at the provided QRPproject manual CD (unfortunately it’s in
on with ST5. The switch is S3, the battery main switch. Connect a 1xUM German only). Under DipIt you find a collection of articles Dipping and
switch with the help of to three-wire cables/plug combination with St4. using a Dipper. Don’t let it bother you to that all the literature is from the
The switch is S4, circuit breakers for the +7dBm amplifier. years 1965 to 1975, it also add a few newer things. Apart from the fact
Connect the 10-turn potentiometer with the pin 1,2,3. Use the lugs. Build that Dipping was more heavily used in the past with older equipment (sen-
the jack headset-phone into the foot of the bottom case (beside the batte- sitivity frequency dial etc.) all the described methods directly transfer to
ry pack) uses today.
Connect the 5mm LED with the help of a 2-wire cable/plug combination
with St2. The cathode (short leg) goes on ST2/2, that is the ground side. If you read all this and tried it out you will have fun with the DipIt and
Use the plastic LED grommett for mounting the assembly in the case. Con- then can also say:
nect the 3mm LED with the help of two wires with the circuit board dril-
lings at the position St 6. St6 may not be installed, since otherwise the I Build the DipIt
switch fits above and the housing cannot not be closed. The short leg
(cathode) comes into the drilling St6/2 (ground side) A Cinch (phono) We wish you much fun and Dipping

November 22.2007
socket screws into the front wall of the lower shell and connects the interi-
or pin with pin 4 and the ground connection with pin 5. This phono socket The QRPproject team
is the input to the overlapping frequency meter. The second Cinch socket
screws into the front wall and connects the interior pole with pin 6 and the
ground side with pin 7. This Cinch(phono) socket is the output of the
28