Frequency Modification
1. Remove the case. I *think* you can remove either the top cover
or the bottom cover to get to the PC board with the jumpers.
It will be a small PC board immediately behind the front panel.
2. Locate "J2". There will be a jumper on pins P3 and P4.
3. Remove this jumper to expand coverage to 26 MHz - 29.7 MHz.
4. Move the jumper from P3-P4 to P1-P2 to expand coverage to
26 MHz - 32 MHz.
5. After moving (or removing) the jumper, press the CPU reset button
(located below J2).
NOTE: Operation between 30-32MHz may require retuning the VCO.
CB Channel Readout Modification
1. Locate J1. There will be a jumper on pins P1-P2.
2. Remove jumper and place on P2-P3.
3. Press the LOCK button on the front panel. The readout will now
display the CB channel number 1-40 -- also will display "A" channels.
4. Press LOCK again to return to VFO mode.
NOTE: The SHF button will not operate while in CB mode.
This modification will disable the frequency lock function.
CB Channel 9 Select Modification
1. Locate J3. There is a jumper between P1-P2.
2. Remove the jumper and place it on P2-P3.
3. Press the "roger beep" button to go directly to CB Channel 9.
NOTE: Doing this modification makes it impossible to turn off the
roger beep feature (unless, *possibly* you make sure the
roger beep is turned off before moving the jumper. I'm not
sure).
-
"Tuneup" Modifications
Adjust VR14 (AMC) for maximum forward modification. Mod limiter
Q32 can be removed for more modulation, but it also disables VR12
(SSB ALC) and disables variable power for SSB. I do not recommend
removing Q32; you'll have plenty of modulation as is.
Tune L34, L13, L14, L46 and L10 in AM mode for maximum forward
swing, using a peak-reading wattmeter. Try to balance for even power
from top to bottom of frequency range.
NOTE: You'll have a LOT of trouble identifying these cans. Sorry,
I don't know for sure where they are either.
Adjust VR13 (AM High Power) for 12 watts dead key with the front
panel RF power control at maximum. Adjust VR15 (AM Low Power) for
2 watts dead key with front panel RF power control at minimum.
>From the 12-watt dead key you should see a forward swing of 30-40 watts.
>From the 2-watt dead key you should see a forward swing of 18-20 watts.
Adjust VR12 (SSB High Power ALC) for maximum PEP on SSB, then
back off just a little, with front panel RF power control at maximum.
Adjust VR16 (SSB Low Power ALC) for 5-6 watts PEP on SSB with front
panel RF power control at minimum. You should see 40-50 watts PEP
on SSB with front panel RF power control at maximum.
--------------------------------------------------------------------
Microphone wiring diagram
Pin 1 -- shield
Pin 2 -- Audio
Pin 3 -- Transmit
Pin 4 -- Receive
Pin 5 -- Frequency select up \ These might be reversed.
Pin 6 -- Frequency select down /
---------------------------------------------------------------
