Re: Need Secondary wire source

["Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I've wound coils with both monofilament spacing and very heavy woven
cotton thread spacing.  I forget the name of the latter, but left it in
place.  After winding the coils (by hand, mounted on very very crude
centers) I gave them a very light coat of thinned urethane varnish. 
When that had dried I pulled the monofilament out and had a very neat
space-wound coil.  Diameter was 4", winding length 18", and wire sas #28
single formvar. Bottom line was that, in accordance with the comment
below, it certainly wasn't worth the bother, and the lower secondary
inductance ran the resonant frequency higher and the things didn't work
as well as close wound.  Don't bother!

	By the way, turning the coil by hand has the big advantage that, if
something goes wrong, you just stop winding and put a piece of
pre-prepared masking tape down to hold the wire while you sit and
think.  Winding a 1000 turn coil this way takes a couple of hours, but
probably a better use of the time than watching baseball on TV and
watching baseball.  If you get the first few turns started neatly (I
circle the form with masking tape to delimit the starting turn) it is
simple and easy.

Ed


> [kch] Although I've not done it, I feel intuitively that simultaneously
> winding fishing line & wire is something I don't want to tackle.  I'm
> contemplating the winding-on first of a cotton twine to form a spiral
> track, with winding-pitch larger than the wire diameter.  After
> stabilizing that with, perhaps, a very thin varnish or "water seal"
> preparation, I would then wind the wire over the twine.  Comments,
> anyone?
> 
> >
> > My $.02 on spacewound secondaries:
> > They are a waste of time.
> > Don't bother unless you must use a smaller size wire than the
> > optimum for
> > that diameter secondary.