On Sep 18, 2005, at 6:09 AM, k7rdx wrote:
> How much heat(Can your meter handle)
The ampmeter is connected through wires to the xfmr, so it sees no heat.
> and for how long can your AC meter be
> used for this?
Probably several more decades.
> Vacuum impregnation with polyester varnish is the modern way
> to restore/protect open frame transformers...Jim..
This method requirers no vacuum chamber, however the process is
necessarily somewhat slower,
> ----- 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
>>>
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>>
>> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
>
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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