Re: secondary wire/ pri spacing, also spun toroid availability

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

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

In a message dated 7/14/01 9:43:44 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

[ Note to all:  Toroid availability comments are all the way at the
bottom.  JF ]

> > Original poster: "christopher carsten by way of
>  > Terry Fritz <twftesla-at-qwest-dot-net>" <ctom-at-toast-dot-net>
>  > 
>  > Good afternoon, I have 2 questions which I am sure
>  > someone could help me out
>  > with. I have a 2000' spool of 24awg plastic
>  > insulated wire that I would like
>  > to put into service on my 7" secondary. Are there
>  > any drawbacks to using
>  > this type of wire? I see that most of you use enamel
>  > stuff, and I have in
>  > the past as well. would the insulation give the
>  > effect of space winding?
>  > And second, I am using a 3/8 Cu. flat spiral
>  > primary, the spacing between
>  > windings is about 1", would I get better results
>  > having closer spacing? I am
>  > currently using a few 15/30 nst's but will be
>  > switching over to mot's soon.
>  > Thanks in advance,
>  > Chris 
>  > 

Chris,

In one comparison test, I removed my 6" x 24" secondary wound
with 1700 turns of 28awg magnet wire, and replaced it with a 7" 
x 19" secondary wound with 550 turns of 24awg plastic insulated
wire, and changed to a thicker diameter fewer-turn primary to
keep the coil in tune.  The spark length decreased from 42" down
to about 37".  Thus, I see the main concern as a possible reduction
in spark output if not enough turns are used on the secondary.  If
you make the secondary rather tall at 38" or so, this will help by
increasing the number of turns.  Although too large secondaries
are not that efficient either.  The wire will work fine, the coil just
may not be as efficient as it could otherwise be.

I have some comments about this sort of thing at:

   http://hometown.aol-dot-com/futuret/page3.html

if you haven't seen this already.  (Click on theory).

Regarding the primary spacing, I like to use 3/8" spacing for a
3/8" tubing.  You may be able to use 1/4" spacing, or 5/16"
spacing.  I do like rather small primaries (small in size, but large
in inductance, for lower spark gap losses).

Note to all:    I now have small toroids available for delivery as
per my recent posting.  These are the 1.75" x 6" spun aluminum
quality spin-finish toroids, and they can be seen at the website
listed above.  (click on toroids).

John Freau