RE: home-brew tranny, and depotting NST's

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

Original poster: "Andy Cleary" <gemware2-at-dreamscape-dot-com> 

Hi Chris!  In terms of the home-brew transformer, I'll have to let you know
in a few weeks!  I've got one monster 15KVA core that I plan on rewinding
over Christmas break, and I'll fill you in on what I did, and how it works
out.  I think there are others on the list who have tried it and found
success.
	In terms of the depotting procedure, I'll tell you what I do - First thing,
try to find an old space-heater (one of those things that sits on the floor,
with the resistance wire that heats up red and provides heat).  If it is a
good one, you can leave it together, otherwise take out the metal support
tray and the resistance wires.  Then, take your transformer, take off the
top, and set it upside-down on two rods, held up by other NSTs (or a similar
height)  Then place a tray below it, to catch some tar.  Turn on the heater,
set up several fans, and let it run for about 1.5-2 hr.  Make sure to do it
outside for it creates many noxious fumes that could be harmful if they are
not removed!
	After that time has elapsed go back to the NST with a thick pair of gloves,
some small scraping tools, and wire snipers.  While the NST and tar is still
hot(Be Careful), you can use the gloves and tear off the tar easily, and
scrape down the core and remaining tar with the scraping tools (any old
piece of plastic or metal will do).  They key is that it must be hot to work
with properly!  You can cut the two primary wires, and secondary wires close
to the insulators, and take those out - while still leaving plenty of wire
on the NST.  And then, while it is still warm, throw the tranny in a bucket
of kerosene to dissolve any other tar that might be on it, perhaps using an
old toothbrush and giving it a scrub now and then.  Leave for maybe a day or
two, then take it out and wipe it down with a rag, and you're good!
	That is the method that I use.  I can guarantee effectiveness, but I can't
guarantee safety!  Others may have to comment if my method is flawed in that
respect.

-Andy C.

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, December 07, 2000 9:29 AM
To: tesla-at-pupman-dot-com
Subject: home-brew tranny, and depotting NST's


Original poster: "Chris Dobson" <cdobson-at-microtech-dot-com.au>

Hi all,

A couple of questions : does anybody have much experience winding their own
trannies, especially on straight cores, and secondly, what is the best way
to
depot an NST . . . I cooked one in an oven, but the enamel on the primary
windings (which is what I wanted) got carbonised and therefore U/S. Any
comments?

Chris

Riana, TAS