05-29-2011, 04:36 PM
Hi Bob,
Well, it wouldn't be unusual to note some drift in the first 15 minutes but the question is how much is too much. In relative terms you should be able to turn it on to an AM station and maybe have to touch it up slightly once after warmup. Shortwave would be different.
I can't think think of a scenario where any of the Bakelite caps would cause this unless they were really leaky and pulling down the voltage - and that's not out of the realm of possibility. I'd rebuild them on general principle because there's so many other potential problems that could develop.
If you have another 6A7 handy you might try it. I've caught excessive drift in many radios due to some problem with the LO/Converter tube.
Just my 2 cents.
-Bill
Well, it wouldn't be unusual to note some drift in the first 15 minutes but the question is how much is too much. In relative terms you should be able to turn it on to an AM station and maybe have to touch it up slightly once after warmup. Shortwave would be different.
I can't think think of a scenario where any of the Bakelite caps would cause this unless they were really leaky and pulling down the voltage - and that's not out of the realm of possibility. I'd rebuild them on general principle because there's so many other potential problems that could develop.
If you have another 6A7 handy you might try it. I've caught excessive drift in many radios due to some problem with the LO/Converter tube.
Just my 2 cents.
-Bill
