[TV MAN]

I believe I have the intermittent solved! It was the 70 ohm section of the large voltage divider/bias resistor. I replaced that section with a 2w carbon resistor and have a good volume control installed. It has been proving itself good for the last two weeks.

My radio on "Life Support"
   

Volume control repair and replacement for 70 ohm resistor:
   

Underside shot of completed chassis:
   

It's sitting on my bench playing after touching up the alignment:
   


This was a very difficult problem to solve, and tested about every skill and piece of test equipment I own! One thing I noted about this fault, it didnt have the usual sharp static of a bad connection, it had more of a "thumping" type sound which could be best heard with no modulation on the generator.

In the end, a Simpson 260 on the microamp setting in series with a pot so I wouldnt trip the breaker, lead me to the problem. Voltage tests were useless. Resistance tests also showed correctly. When I unsoldered the leads on the big resistor, I found 3 clipped off pieces of wire in the solder, so I would say I wasnt the only one trying to track this problem down, and is probably what put the radio in the attic. I'll play it for a couple of weeks to make sure no other problems show up, and check back in with the results.