Downward modulation on viking ll
 

Ralph Mowery wrote:
Tried several things. Replaced the tube HV rectifiers with solid state
diodes. Voltage dropped about 25 volts under modulation while power out
still droped about 20 watts.

That's probably not a bad idea, but yes, not related to any problem.

I am beginning to think it is just a watt meter problem. I used a
Struthers watt meter and it goes up with modulation like I would expect.

As I said earlier in the thread, ignore the watt meter. Don't believe the
watt meter. Look at the plate current. If the plate current stays pretty
steady, you're okay. If the plate current is sagging, either the waveform
is asymmetric (which is fine on a voice but not fine on a sine wave) or
the supply is sagging.

If it drops on a voice but doesn't drop on a test sine wave, flip the
microphone polarity so it rises on your voice and you'll sound louder
in a pileup...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."