Mike Knudsen wrote:


2) switch to fast recovery diodes.


How would these be specified in a catalog? "Fast recovery power diodes"?
Thanks, Mike K.

Yes. A number like 1N5407 rings a bell but I'm saying that on memory.
Actually I've never seen a case where the diodes caused any audible
noise in a regular ole radio although I hear this recommendation often.
Tunable hum at times maybe.

If this set is making a racket like powerline noise as opposed to a 60
cycle hum it pretty much has to be some leakage in the AC
components...plug, switch, xfmr, etc.

Remotely possible is some sort of weird rf oscillation. Should be easy
to sort between the two by powering it up on DC.

-BM