"William Sommerwerck" wrote in message
. ..
"Brenda Ann" wrote in message
...

"William Sommerwerck" wrote in message
. ..

Based on what I can figure out, the plate current is 1mA. That should
put the cathode voltage at 60V, not 70V -- which still seems rather
high.
I assume you've checked the obvious stuff like the resistor values.

Indeed I have. In fact, every component but the tube itself in the
circuit
is new, as I had to rebuild the power supply, first audio, driver,
output,
detector and AGC circuits back to factory design. This one's a puzzle
for me. The voltages on that stage are strange. Plate voltage is quite
high, IIRC, around 240 volts, and the grid is at essentially zero. It's
all
supposed to be a part of that squelch circuit, I'm sure... perhaps it's
staying in the squelched mode for some reason.

I like to say that "science" is not about "facts", but about asking the
right questions. I think you've made the right observation -- the unit is
stuck in squelch mode.

One other possibility... double-check your wiring. (No offense intended.)


Well.... it's DONE!

Wasn't my wiring, per se, but it was something I hadn't yet bothered to
change. It was an extremely leaky C17. I couldn't believe it (though
obviously I should have just gone and replaced all the caps FIRST as a
matter of course.. but I'm the sort that loves the challenge of actually
troubleshooting a radio before shotgunning it.) I clipped it out of the
circuit, and the gain on the first audio stage came right up, all the
voltages are now within 5 volts of what they're supposed to be. I went ahead
at that point and replaced all the rest of the paper caps, cleaned the
controls, replaced the destroyed mounting grommets on the tuner mechanism,
and replaced the burned out dial lights. The thing works like new. Even the
squelch circuit works like it should. I'm a really happy camper (and my
friend who owns the radio will be even happier, since it's now up to snuff
after sitting in my basement for 3 years gathering rust and mold while I
looked and looked for a schematic under the wrong make....)