Thanks everyone for the help/suggestions and info. To answer some of the question:
- Did roll the the tubes with spares and no changes
- Sent to CJ something like 30 years ago, they couldn't find the problem
- Have used Deoxit on knobs and connectors (but it has also been a few years)
- Location is central Indiana
I'll probably work on poking around a bit more and see what I can come up with. Appreciate all the help.

