Firstly, thanks all for the very positive responses I've received so far.
I redid the neutralizing circuit and instead of a hard wired feed off the
anode through a blocking cap to the neutralizing cap, I setup a single
adjustable disc looking at an anode much like a gimmick wire would do and
fed that to the grids. I'm questioning exactly where to apply this, though.
At present it's going to the input side of the grid blocking cap.
I pulled all the tubes and tested all the voltages and resistances at the
sockets.
I put the plate load resistor in place and with the Anritsu looking into
the output I tuned the deck and was able to attain a 60db return loss and
an absolute flat SWR.
Then I hooked up the service monitor and using the tracking generator and
spectrum analyzer, I was able to get a deep null at the op freq. It all
looked perfect.
But, and you knew this was coming, when I apply voltage and key the amp
without excitation it instantly goes into runaway.
... and yes Bill, arcs and sparks and fireworks ensued. Gonna have to put a
tag on the switch when I've got one installed.
73, Roger
AI7RR
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