[R-390] Odd problem - Raspy BFO

[Bill Cotter]

Greetings everyone,

I have a BFO problem with my EAC R-390A (completely recapped & 
restored) that has eluded me after doing all the usual easy stuff 
(test/swap tubes, measure voltages, etc). While listening to an AM 
station, strong or weak, or turning on the calibrator, and I flip 
on the BFO, the note is raspy and harsh. Otherwise the receiver 
works great. I have checked for fil/cath shorts in the tubes, dirty 
DC, AVC, etc and have not found the culprit.

It's time to bring out the Tek-475 and snoop around. My first 
suspicion is a leaky 12pf C535 or 100pf C530.

Any thoughts/suggestions/experiences? It's time for me to step up 
to "level-2" troubleshooting.

73 Bill N4LG