Actually, the way this circuit is designed, any ripple or pulses in the DC
supply will be picked up and amplified the same way as pulses from the GM
tube. I guess it was never designed to operate on an AC power supply, but
I'm sure there's some way areound the problem.
I've replaced most of the capacitors (all are high voltage ceramics).

"Baron" wrote in message
...
Chris F. Inscribed thus:

At this point, I think you're right - it's probably issue with the B+
supply, probably a combination of poor filtering and inadequate output
current. After tracing out the schematic that's about the only
conclusion I can come to.

Since you get clicks when the tube is not connected, have you checked
the EHT supply. It probably has bad caps in there. Something breaking
down as the EHT rises.

--
Best Regards:
Baron.