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Re: repair

At 10:25 PM 2/3/97 -0700, you wrote:
>> > > > Subject: Re: repair
>> Subject: Re: repair
>> > > > Subject: Re: repair
>
>Subscriber: unknown-at-apc-dot-net Mon Feb  3 21:51:44 1997
>Date: Sun, 02 Feb 1997 01:17:02 -0800
>From: Open Minded <unknown-at-apc-dot-net>
>To: tesla-at-pupman-dot-com
>Subject: Re: repair
>
>Tesla List wrote:
>> 
>> > > > Subject: Re: repair
>> 
>> Subscriber: major-at-vicksburg-dot-com Fri Jan 31 23:12:03 1997
>> Date: Fri, 31 Jan 1997 23:38:56 -0600
>> From: RODERICK MAXWELL <major-at-vicksburg-dot-com>
>> To: Tesla List <tesla-at-poodle.pupman-dot-com>
>> Subject: Re: repair
>> 
>> Tesla List wrote:
>> >
>> > Maybe one of these days I'll take pictures and post them.
>> >
>> > Chip
>> >
>> >
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-> >
Moderation in all things, including moderation
>> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-> >
>> > On Wed, 29 Jan 1997, RODERICK MAXWELL wrote:
>> >
>> > > Tesla List wrote:
>> > > >
>> > > > Subscriber: major-at-vicksburg-dot-com Tue Jan 28 22:49:45 1997
>> > > > Date: Tue, 28 Jan 1997 08:12:24 -0600
>> > > > From: RODERICK MAXWELL <major-at-vicksburg-dot-com>
>> > > > To: tesla-at-pupman-dot-com
>> > > > Subject: Re: repair
>> > > >
>> > > > Tesla List wrote:
>> > > > >
>> > > > <SNIP>
>
>
>
>>   I just unpotted the first of four neon transformers that I got from a
>> sign shop in town. The guy there told me they were 15Kv -at-30ma. I'm sure
>> they are 15Kv but not so sure about the current rating as the plates
>> have all been removed. I kind of went back to the dark ages in the way I
>> removed the potting. I boiled them in oil! I used a burner out of a old
>> space heater to heat the metal pan pan filled with diesel! I know this
>> sounds dangerous folks but it was a good 20' away from anything that
>> would burn including yours truly. It really speeds up the process as it
>> uses solvent and heat to disolve the tar. Just don't try this at home
>> folks! The core looks, and disassembles the same way discribed in the
>> archives. One secondary reads megohm resistance and is probably fried.
>> The other reads a little over 8kohms. Is this the usual resistance of a
>> 15kv secondary? Or is this side shorted???
>> 
>>                                  Frankensteins Helper
>>                                         Max
>
>
>High resistance (megohm region) indicates an open winding. A carbon-
>shorted winding usually reads like a good winding as the short
>resistance is quite high, though quite low enough for the HV!
>
>- Brent
>
>
Yes Brent has that correct. You can't tell if a secondary has
a carbon track short until you run it. And then it may not
arc over until you run it on a coil.

Don't give up on a open secondary. Quite often only a few turns
on the outside layer are damaged. I have removed as many as 40
turns from a secondary to get down to good turns. The loss of
a few turns wont affect the output much. Isolate the good
free end and attach a new lead. Use small diameter stranded wire.
I use 28 ga teflon covered stranded wire. Make a good solder 
connection and bed down the joint with an adhesive. I used hot glue
and epoxy succesfully.
My latest rebuild is getting coated with polyester resin. Not
as convenient as epoxy but a lot cheaper.

Unless a secondary is really toasted it can usually be salvaged.

Mike Hammer
mhammer-at-misslink-dot-net