[Johnson] Invader Low Voltage Problem

[David C. Hallam]

I have an Invader 2000 with a low voltage problem in the 330VDC supply 
for the exciter section.  It is running about 60 to 70VDC low in both 
standby and transmit.

The transformer is supplying 620VAC to the rectifier.

I tried two different 5U4 rectifier tubes with no change.

I checked the filter capacitor for leakage and found about .1 mA at 
450VDC, so I would say it is OK.

I did a resistance check and didn't see any values which were out of 
line from the last time I did it.

I checked all the tubes on my tube tester and the all tested good 
(whatever that means).

I tried tube substitution of some but not all of the tubes.
I have not done any testing or substitution the 6146's.

Another symptom that may or may not be related is when I switch the amp 
section on, the finals draw no idling plate current.

I am sort of stumped as to where to go next.  Any suggestions would be 
appreciated.

David
KC2JD/4