Re: Why people don't use MOTs in a TC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Loudner, Godfrey by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU>
> 
> Hi Ed
> 
> I took a good look at some of the many mots in my possession. The primary
> coil is insulated for high voltage from the core by some sort of  varnished
> paper and, where the insulation is not substantial, there is good clearances
> between the wire and the core. With few exceptions, the bottom of secondary
> is grounded to the core. The secondary is insulated with varnished paper
> much the same as the primary. But it is hard to believe that such insulation
> could hold off potentials higher than its original intentions. Many mot
> coilers talk about intervention with extra insulation, especially submersion
> under transformer oil. Mot coilers also seem to be selective in choosing
> mots with the best insulation. I don't see that oil can penetrate the
> impregnate of the secondary coil, but I believe that coil can completely
> penetrate the primary, adding substantial insulation. Oil should also do
> wonders in preventing external arcing, especially very clean and moisture
> free oil.
> 
> Also I think that insulation materials can be underestimated. One time I
> brought together two leads of magnet wire connected to a 10kV NST. I was
> surprised that no arc formed between the leads and I feared that the NST had
> gone dead. Then I realized that the enamel on the magnet wire was hold off
> the 10kV!

	Not for long!  Insulation can/will fail over time due to corona.  In
the case of your magnet wire I'm sure there was a lot of corona, and bet
you didn't run that test for say 100 hours!

Ed