Please note: This procedure is reengineered by myself and may be not in accordance with
the original procedure from the manufacturer!
So I can´t accept any claims from anybody in case of injuries, problems, damages and losses.
Usage of this procedure is at own risk!
Of course you may ask me or give hints for improvement.
Page 1 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Required Equipment:
Counter, 150MHz
Multimeter, best with analog scale
RF-Generator 145MHz, level adjustable down to 0,05uV
IF-Generator 10,7MHz, FM
2nd RX for 2m or spectrum analyser
Scope, 50MHz with analog output for counter
Dummy load and Power Meter, 145MHz >15W
Resistor 25/20W (2 x 50 parallel)Sweeper 10 … 15MHz
AF-Generator
Microphone and CW-Key
Optional: Spectrum analyzer with attenuator or Scope >250MHz for optimum of PA linearity
Page 2 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
AF
1) Mode „USB“
2) No microphone connected; „MIC GAIN“ control to CCW
3) „VOX“ On
4) Adjust R50 that VOX doesn´t trip (search for the point where VOX trips without
Modulation and set R50 shortly before this point.
5) Check that for all modes (FM, USB, LSB, CW) VOX doesn’t trip without modulation
6) “CAL” switched on, connect counter to CP1. Best use analog scope with Y-output
7) Wait 1 minute
8) Adjust frequency to 2,500000 MHz
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 4 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
GIF
1) Receive “R”
2) Connect Counter (AC-coupled) to Emitter of Q14. Best use analog scope with Y-
output
3) Mode “USB” adjust C61 to 10,69850 MHZ (X1)
4) Mode “LSB” adjust C66 to 10,70150 MHz (X2)
5) There may be some interaction so repeat 3 and 4 if necessary
6) Mode “CW” frequency should remain at 10,70150 MHz (“RX”)
7) Connect dummy load; Transmit “T”
8) Mode “CW” frequency should move to nearly 10,70000 MHz (not more than +/-
500Hz)
9) Mode “FM” frequency should move to nearly 10,70000 MHz (not more than +/-
500Hz)
10) Receive “R”
11) Note: At “FM” and receive “R” there is no output of BFO
12) Mode USB: Set R41 for just a little bit above S=0 (S-Meter just moves) on S-Meter
13) Tune in weak signal at 145,000MHz just enough to move S-Meter to S=5
14) Tune L1, L6, L8, L9, L10 for maximum
15) Tune in signal 50Mikrovolt 145,000MHz: Set R40 for S=9
16) Repeat steps 12 and 15 if necessary
17) Mode “FM”
18) Adjust R1 on Main board near FM-Unit to S=9
19) Mode “USB”
20) Connect power meter, scope or analyzer with attenuator; Transmit “T”
21) Mode “USB” with PA operating (jumper P11/J11); adjust R66 for best carrier
suppression
22) Check carrier suppression with “LSB”
23) Receive “R”
24) Connect AF signal (2kHz, 10mVpp) to MIC-Input
25) Set “MIC GAIN” to center position
26) Mode “USB”
27) Transmit “T”
28) Adjust output power with R69 to app.8 to 10W
29) Receive “R”
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 6 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 7 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
RF
1) Set “RF GAIN” to “H”
2) Weak signal at 145,000MHz just enough to move S-Meter to S=5
3) Tune L1, L6 and L7 for maximum AF or S-meter
4) Unmount RF-Module (one clamp at each end) and turn RF-module upside down
5) Tune L2 to L5 for maximum
6) Mount RF-Module
7) If a big increase of sensitivity has been achieved, then repeat adjustment of S-Meter
(Look for GIF, step 14)
Note:
The resistor at the drain of Q1 (18Ohm) is a modification for damping oscillations in case
of badly matched antennas!
Page 8 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Helical Filter
These filters (cores) are very sensitive, use appropriate tool only!
Adjust only if you feel that these filters are mismatched!
1) Weak signal at 145,000MHz, just enough to move S-Meter to S=1 or 2
2) Connect sensitive AF-Voltmeter or scope parallel to speaker
3) Adjust both helical filters to maximum AF
4) Repeat at 144,000 and 145,999MHz
5) If you observe differences tune for maximum at 144,500MHz
Page 9 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Premix
1) “CAL” (Calibrator) switched off
2) Receive “R”, mode USB
3) Connect Counter (AC-coupled) to Collector of Q3. Best use analog scope with Y-
output
4) Connect DC-Voltmeter or Scope with 10:1 probe to common cathodes of D4 and D5.
5) “RIT” centered: Trim R8 for app. 0,3VDC
6) Set “Coarse” to 144 MHZ (simplex).
7) Measure frequency; should be app. 15,239 MHz.
8) Check: Tuning “RIT” should change frequency app. +/- 400 Hz – symmetrically to both
sides
9) If not readjust R8 and check again – back to 7)
10) “RIT” centered again.
11) Measure frequency; should be app. 15,239 MHz.
12) Switch to transmit “T”.
13) Adjust R9 for exactly same frequency as 10)
Note: Mode has to be “USB” not “FM”!
In FM there is a small difference in RIT adjustment compared with USB/LSB/CW!
17) “Coarse” 145 MHz DUPLX: Switch to “T” and adjust C70 to exactly 15,289375 MHz
(X3)
18) Check: 145 MHz in DUPLEX is on “RX” same as in 15 (15,364375 MHz)
19) Recheck 15, 16 and 17 in “R” and “T”
20) Connect AF signal (2kHz, 10mVpp) to MIC-Input
21) Connect Scope to Pin 9 of IC1 (MC3301P)
22) Mode “FM”, Transmit “T”
23) Adjust R52 for symmetrical clipping at Pin 9 of IC1;
adjust amplitude with “MIC GAIN” and R53 if necessary
24) DC-Level at Pin 9 of IC1 should be app. 4,5 to 5,0VDC without AF-Input
25) Check that AF at Pin 9 of IC1 is just clipped
26) Connect Jumper P1 to J3 and adjust FM-Deviation with R61 to 5.0kHz
27) Connect Jumper P1 to J4 and adjust FM-Deviation with R62 to 2.5KHz (for narrow
band FM)
28) Switch back to receive “R”
29) Note: Maximum deviation with constant AF input will be at 2.4kHz due to phase
modulation and frequency response of IC1 (R57/R59/R60/C59/C60)
Page 10 (36)
Up to now, I´ve no procedure for aligning L3 to L14.
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 11 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 12 (36)
Here some measurements at TP1 to TP3:
At TP1, connected to first doubler, the scope shows:
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Measured DC-levels:
TP1: 1,3VDC
TP2: 1,2VDC
TP3: 0,23VDC
It could be assumed, that the inductors L3 to L7 will be tuned for maximum DC-levels at
the emitters of the corresponding frequency doublers Q4 to Q6:
L3 > Q4 (TP1)
L4/L5 > Q5 (TP2)
L6/L7 > Q6 (TP3)
L8…L14: Tune for maximum output of J2, Pin 5 (app. 134MHz).
Couldn´t check this procedure – all coils are fixed with wax and I don´t want to destroy
them.
As long as you have no problems with the Premix keep your fingers away from it!
Page 13 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
FM-IF
Alignment of FM-Unit can only be done outside the transceiver.
Use pins to connect supply (9V), ground, signals and meters acc. to the picture.
IMPORTANT:
An external trimmer R1 (10kOhm) has also to be connected to ground, otherwise Q1
wouldn´t operate.
1) Connect counter to TP2 (high impedance); frequency should be 10,245MHz +/-1kHz
Use analog scope, probe 10:1, with Y-output to connect the counter if available
2) Connect IF-generator 10,700MHz, 1mV, unmodulated to pin 3 and 4(Gnd)
3) Connect DC-voltmeter to pin 10
4) Adjust L1 and L2 for max. negative AGC-voltage at pin 10; reduce amplitude of IF-
generator as far as possible to find the point of best sensitivity; try variation of R1
5) FM-modulated IF-signal with sinus 1kHz and 5kHz deviation
6) Connect scope to pin 9, AF audio
7) Connect DC-voltmeter to pin 6, center meter
8) Adjust L3 and L4 for best demodulation (scope) and 0V at center meter
9) Reinstall FM-Unit into the transceiver
10) Mode “FM”, “RX”
11) Tune in signal 50Mikrovolt 145,000MHz: Set R1 (mainboard nearby the FM-Unit) for
S=9
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 15 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 16 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
T-MIX
1) Alignment requires an sweeper
2) Coarse “145MHz” *)
3) Connect sweeper to the external VFO input: J2 pins 8 (Gnd) and 9
4) Set sweep to 10,000 to 13,000MHz, app. 0dBm (700mVpp) *)
5) Mode “FM”
6) 50 Demodulator (10W) and viewer (scope) at Antenna output
7) Sweeper output to zero
8) “TX”
9) Set sweeper output to app. 1W at antenna output
10) Tune L1 to maximum
11) Tune L3 to L9 to maximum and flat response in the range of 10,385 to 12,385MHz *)
12) Also tune L2 and L3 of the Buffer Amplifier for flat response (see Buffer Amplifier)
13) Reduce sweeper output when 1W at antenna output is exceeded
14) Tune C32, C35, C43 and C44 to maximum and flat response in the range of 10,385 to
12,385MHz
15) Go back to 10 until result is satisfying: Flat response (+/- 3dB in the range of 10,385
to 12,385MHz
*) With “Coarse” 145MHz and sweeper from 10,385 to 13,385MHz the output is 144 to
146MHz
Page 17 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 18 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Buffer Amplifier
This amplifier is located on the bottom of the chassis. It´s not necessary to remove the
FM-Unit, adjustment of L2 and L3 can be made with the FM-Unit in place through the
two holes in the clamp.
Alignment: See T-MIX
Page 19 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Final/PA
1) “Coarse” to 145MHz, VFO to 000 (equals 145,000MHz)
2) Remove heatsink from rear of PA-unit (from now on observe it´s temperature)
3) Connect Dummyload 50W and Powermeter to antenna output
4) Remove jumper P11 from J11
5) Switch to “CW”, unkeyed! Adjustment of Bias of Q1 and Q2 without HF
6) Connect A-meter between pin 2 & 3 of J11 (measures current of Q1)
7) Switch to “TX”
8) Adjust R3 for app. 30 to 40mA
9) Switch to “RX”
10) Connect A-meter between pin 1 & 4 of J11 (measures current of Q2)
11) Switch to “TX”
12) Adjust R8 for app. 80 to 90mA
13) Switch to “RX”
14) Reinstall jumper P11 at J11
15) Mode “FM”
16) Switch to “TX”
17) Adjust C11, C12, C22, C23 for maximum output; should be 10W
18) Maybe TX-limiter R13 limits the output; then adjust R13 for 10W and go back to 15)
19) Adjust R12 for SWR=0
20) Connect resistor 25/20W to antenna output (2 x 50 parallel)
21) Adjust R17 for reducing TX-output: SWR protection at SWR = 2
22) Repeat steps 18 to 21 if necessary
23) Switch to “RX”
Reinstall the heatsink:
Clean it from old thermal compound and use new one.
Page 20 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 21 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Remove jumper P11 at J11, connect A-meter
Page 22 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
VFO
1) Let the VFO warm up for app. 10 Minutes
2) Adjust tuning range of VFO with L1 to exactly 1000kHz (use internal calibrator as
reference)
3) If you adjust L1, a realignment of the mechanical scale is necessary.
4) Repeat 2) and 3) if necessary
Be very careful! Use plastic trimmers only – otherwise destruction of L1 will result!
(And you are a fool for the rest of you life….)
Page 23 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Mainboard
Only one adjustment is on the mainboard: R1 for the S-meter of the FM-Unit; see GIF and FM-IF
Page 24 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Mainboard
Page 25 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Tone Unit
When the tone is activated (+9V at J1), C1 is not charged (pins 12 and13 low) and via pin
11 (high), the RC-oscillator is activated via pin 2. IC1 is a quad NAND-gate.
After a certain time, C1 is charged via R1 and R2 and blocks the tone generator via pin 11
(low), R3 is a positive feedback for this blocking.
R1 sets the time (duration) for charging C1 and therefore the time, for which the tone is
generated.
R5, R6 and C2 determines the tone frequency; R6 is adjusted to 1750Hz.
R7 sets the tone deviation. The deviation is also affected by R61 and R62 in the PREMIXUnit. So first set R61/R62 in the PREMIXer and after that, align R7.
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
(De-) Installation of the VFO, Sequence
Page 27 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 29 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Don´t loose it!!!
Page 30 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 31 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 32 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
Following pictures show the VFO drive and its (dis-)assembly.
Page 33 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
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DL7MAJ, Oct 20th 2015, Jan 28th 2018
Page 35 (36)
DL7MAJ, Oct 20th 2015, Jan 28th 2018
If you want to contact the author:
Stefan Steger, DL7MAJ, eMail: dl7maj@t-online.de
Homepage: www.dl7maj.de
Page 36 (36)
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