Re: New 4" coil: R.Hull and CSN, Secondary Varnish

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <megavolt121-at-attbi-dot-com>

Dave
  My last secondary used a two part epoxy like "varnish" 
called Pour-On. It creats a hard coat as thick as you 
pour on there which protects the windings quite well.

-alan
> Original poster: "Dave Hartwick by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
> <ddhartwick-at-earthlink-dot-net>
> 
> Guys,
> What is the current thinking on applying secondary insulation, in this case
> MinWax gloss polyurethane? There was a time when multiple coats to build a
> up a thick layer was desirable for  corona suppression, racing arcs, etc.
> Richard Quick was one such advocate.
> 
> I note that Richard Hull advocates minimum or no varnish at all, stating
> that pretty secondaries with lots of varnish are also lossy. I've got about
> 5 coats on the new 4" secondary (#26, 1500 turns) and am thinking that's
> enough, maybe too much. I've never done A B tests with identical secondaries
> that differ only in varnish quantity.
> 
> I also wonder how Glyptal and other substabces compare in terms of
> lossiness.
> 
> 
> Generally regarding Rich Hull's work: I'm now reading his Guide to the
> Colorado Springs Notes--1993, 2nd edition 1995). Here he addresses the
> secondary insulation matter. He also concludes, for example, that cap size
> for a given transformer should be smaller than is generally advocated today.
> He says that a 5kVA 14.4 kV piglet won't handle a 0.06 ufd cap, that 0.005
> ufd is largest a 15/30 NST will power up. This is certainly at odds with
> more recent LTR methods.
> 
> The overall question is what is still viable from work generated 8-10 years
> ago? And that goes for any theory that is some years old now. Certainly,
> much of his conclusions are still valid--Big toroids, magnifier theory.
> Dave Hartwick
> 
> 
> 
> 
>