How much heat(Can your meter handle) and for how long can your AC meter be
used for this?Vacuum impregnation with polyester varnish is the modern way
to restore/protect open frame transformers...Jim..
----- Original Message -----
From: "R.Measures" <r@somis.org>
To: <w8hrq@lemleys.org>
Cc: <amps@contesting.com>; <glowbugs@piobaire.mines.uidaho.edu>;
<AMRadio@mailman.qth.net>
Sent: Sunday, September 18, 2005 4:37 AM
Subject: Re: [Amps] Drying out HV transformers / Chokes
> Hello, Don -- I heat large xfmrs by shorting the primary with an AC
> ampere meter and connecting the secondary to a variac that is connected
> to the electric mains. I increase the the sec. V until I arrive at
> the normal pri. current. I put a folded in half bath towel over the
> unit to hold in heat. After a few hours, the xfmr should be almost too
> hot to touch. Continue for a few days. At this point, the xfmr should
> be dried out. At this point, polyester laminating resin can be poured
> into the windings to fill the air spaces. When the resin hardens, the
> xfmr will not absorb moisture, it will be able to get rid of internal
> heat better, and the insulation will be improved.
> - note - xfmr potting is covered in:
> http://www.somis.org/D-amplifiers3.html
> cheerz
>
> On Sep 17, 2005, at 9:51 PM, Don Lemley wrote:
>
> >
> > Hi all,
> >
> > Ok, I know this has been covered here before, but is there a
> > consensus on how to get the moisture out of HV plate transformers and
> > chokes, so they won't arc on me. And before everyone jumps in with the
> > quick
> > "just put it in an oven on xxx degrees for yy hours", I am working with
> > the
> > iron from a Broadcast transmitter, specifically, the Gates BC-1G so
> > these
> > things are 100, 150 lbs each, and my XYL would REALLY not like it if I
> > tried
> > to put them in her fancy oven. They have been sitting in an
> > un-conditioned
> > but dry hanger/garage for several years, so I am certain they have
> > soaked up
> > a good deal of moisture over that time.
> >
> > Thanks for any suggestions,
> >
> > Don - W8HRQ
> >
> >
> > _______________________________________________
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> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>
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