RE: questions and new web site

To: tesla-at-pupman-dot-com
Subject: RE: questions and new web site
From: Gary Lau 24-May-1999 1957 <lau-at-hdecad.ENET.dec-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Tue, 25 May 1999 06:51:01 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

>Original Poster: Stan <sdarling-at-columbus.rr-dot-com> 
>
>What I have: 10 60ma 15kV NSTs, sixteen inches of 24AWG wound on a 4"dia
>PVC pipe, 50ft. of 3/8" soft copper 'fridge tubing, no toroid and no cap
>at the moment
>
>What size cap do I want and what size toroid?  Are two 60ma NSTs
>overkill on this relatively small coil?  How many turns should I need in
>my primary?  

>1) A while back I remember reading  that it is desirable to keep the H:W
>ratio of the secondary at or under 4:1.  Is this true?

The ratio gets larger for smaller (i.e. 4") diameter coils.

For cap size, depends on how many NST's you use.  If your secondary is
only 16" long (kinda short), one of the 15/60's will probably be all that
you can use.  A general rule of thumb is .01 uF per 15/60 NST, though
there's nothing magical about this number, just a starting point.

Once you settle on no. of NST's and cap size, then you can use Wintesla
(highly recommended) to calculate how many primary turns you need, and
many other things as well.  See http://members.aol-dot-com/rscopper/software.htm
The 3/8" tubing sounds slightly large for use with 1-2 15/60's, but it
will certainly work.  You probably will want 15 or so turns, and 50 feet
may not be enough.  For a toroid, probably something like 5" x 20",
perhaps larger if using 2 NST's.

>2) How much distance should be between the secondary form and the inside
>turn of the primary?

I used just under an inch, but that was cutting it very close.  I'd
recommend 1.5".  But keep the primary as compact as possible, or else you
won't be able to get a good coupling constant k.

>3) What is the best method to affix/hold the turns of the primary?  I
>don't have that much access to serious tools.

Everyone does it differently.  For mine see:
http://people.ne.mediaone-dot-net/lau/tesla/tesla.htm

>4) How does one cut plastic-type materials?

Table saw.

>5) What is the best way to connect components (NST, cap(s), etc). 
>Again, I'm no metalworker so I'm thinking wire.  What should I look for
>and where can I get it?

The wire between the NST and main spark gap need not be heavy, neon sign
wire is fine.  For between the gap, cap, and primary, now you want to be
as heavy and short as possible.  #6 or heavier if possible.  Go to Home
Depot and get comfortable, you'll be seeing them a lot soon.

>6) Where can I get toroids?

You make them, generally from corrogated aluminum duct or corrogated
plastic drain pipe, covered with aluminum tape.  Read, read, read the
archives and web pages.

Regards, Gary Lau
Waltham, MA USA