TRAM D201A low output USB & LSB only

[Crambone]

Radio is working perfectly as receive is very, very strong on all Bands and Channels. On AM I dead key 4.2 watts and swing 28 but on SSB I’m only seeing 10 watts. I went through the ALC c tuning procedure in the manual and I’m not getting any adjustment on R719, R719 sees 97 vdc on leg from R720, on center leg I can adjust from 0 - 97 vdc I set it to 55vdc for now and ground on other leg. I get no power or modulation increase at all stays the same.
On the yellow wire coming from the band switch I see 0vdc rec and upto -90vdc on TX with modulation on both LSB & USB?
I have swapped modulation modules also with a good working one and same issue?

Where to check?

 

[nomadradio]

Where to check?

Oscilloscope trace of the transmitter's output. What you're looking for is "flattopping", or the peaks of your voice waveform being flattened, where they should look pointy.

Makes me wonder if the balanced modulator board you swapped had bad electrolytics in it like the first one.

It only has five electrolytic caps on it. Replace all five and see if this helps.

Can't hurt.

73

 

[Crambone]

Oscilloscope trace of the transmitter's output. What you're looking for is "flattopping", or the peaks of your voice waveform being flattened, where they should look pointy.

Makes me wonder if the balanced modulator board you swapped had bad electrolytics in it like the first one.

It only has five electrolytic caps on it. Replace all five and see if this helps.

Can't hurt.

73

I should have stated all the electrolytic caps and larger resistors have been replaced. I also checked all the tubes prior to anything else being started. I will give a look with the O scope.

 

[nomadradio]

Seeing that the two slug-tuned RF transformers on the BalMod board are peaked would help if this was not done.

73