[AMRadio] transformer rattle - kill or cure?

Todd, KA1KAQ ka1kaq at gmail.com
Wed Dec 23 11:49:15 EST 2009

On Wed, Dec 23, 2009 at 10:39 AM, AirRadio <AirRadio at dsl.pipex.com> wrote:
> I have a mains transformer in my latest boatanchor, it is rattling like mad, eventually goes away after an hour or so, I thought about dropping it in a can of varnish, anyone cured one before, any luck or waste of time?

Sounds like it abates once things settle in thermally.The simple
approach I'd try first Max is to check the tension on any securing
bolts through the transformer laminations or chassis. Sometimes that
takes care of it. Other methods include removing the transformer and
re-sealing the laminations it in hot varnish, or isolating the
transformer from the chassis on rubber bushings. The latter is not a
good idea IMO due to safety concerns with internal shorts which would
otherwise become apparent when the case is grounded to the chassis.

Gary WZ1M is a member of this list and has a transformer rebuilding
business, so he can certainly provide you with some pointers. I think
Don K4KYV and a few others have successfully dealt with similar
problems with success. It might be as simple as tossing he transformer
in the oven for a while on its own if tightening the bolts doesn't
cure it.

~ Todd,  KA1KAQ/4

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