[Elecraft] OT: Audible hum from Astron linear power supply. Fixable?

[Mel Farrer via Elecraft]

Take the cover off and loosen the transformer mounting bolts and slide a piece of cardboard under each corner and see it that cures the vibration.  Mine did that and it fixed it.

Mel, K6KBE



On Sunday, September 14, 2014 7:01 AM, Barry <w2up at comcast.net> wrote:
 


I have an Astron RS-70M that I use to power the station.  It on the carpeted
floor under a desk.  It's probably 30 years old now.  I've been inactive for
several months, so it's been off all summer.  Now when I turn it on, it has
an annoying, low-pitched audible hum.  All the screws are tight, though when
I press down on the top of the case, it goes away.  Any thoughts on how to
quiet it down?
Tnx,
Barry W2UP



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