[Central-Electronics] 100V question

[Donald Ball]

I am having problems with the regulated 150v line. It will shift down 1volt
when I transmit. This causes my audio to shift in pitch. As is I cannot use
the rig like this. It seems the 350v line will drop to around 310 volts
when I key up. I think this is starving the current required to keep the
150 stable. I think this is related to the CW chirp that is mentioned in
the manual. When i remove the 6BQ5 tube this voltage shift goes away. I am
assuming the bias on that tube is off.. ?? I measure the correct voltages
around the tube, but the tube might be too hot and requires less bias??
try different 6BQ5 tubes??   I have tried an external 150v source and its
stable. I could modify the rig to use a series pass IGBT and use the OA2 as
the reference, but think this is covering up a problem that can be
resolved. I think this 100v drifts worst that my Swan 500. Do these rigs
drift that bad? My 20a and 458 VFO are rock solid. I also have a 200V I am
restoring and it is really different from the 100v, it makes me think the
100v had issues and the 200v was the solution. Can someone shed some light
on this?