Re: Itsy Bitsy Teeny Weeny...

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

Original poster: "Ryan Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <xanth-at-voyager-dot-net>

Matthew, List,

After reading much on this list, I too decided to build a small coil.  I
completed it about a year ago and it works supprisingly well (for being my
first coil)!  The secondary is 7/8"x5" wound with 38 AWG magnet wire.  For a
topload I made two toriods, the first a 1.25"x5" (i think) and on top a
1.5"x8".  It's driven with a 5/30 NST, ~15nF MMC made with the Panasonic
caps from Digikey, and a small copper pipe sparkgap.  The stand is made
entirely out of plexiglass and the whole thing only takes up a space 7"x7"
and around 15" tall.

I ran it at first with no RF ground but got sparks everywhere I didn't want
them!  So I built a "cage" around it out of fine hardware cloth and the
results improved greatly.  Now I get constant 6 inch streamers and very
often 8 inchers to the edge of the cage.

I finally got a RF ground in the lab and tried it with that and to my
supprise...no streamers...but HEAVY radiated rf.  With the ground it sent
test equiptment crazy at 40 feet away and I could light a small florensent
bulb (10W) brightly at 8 feet.  I've been meaning to take some pictures of
it so I'll try to get them posted with specifics so I can get the lists
feedback and suggestions.

Ryan Phillips


>
> I was interested to read the various definitions of coil sizes in recent
> posts...
>
> The smallest have caught my imagination - I have a potential application
> (I won't say what until *I* have decided if it's a daft idea!) for a
> very small TC - something like a 3/4"x5" secondary with an aluminised
> (tape) table tennis ball as a topload.  I was thinking of running it
> from a DC-DC convertor with a VERY SMALL triggered gap but, before I go
> charging out and doing any serious design, I'd be interested to know
> what others have done.
>
> Obviously I don't want to be mucking around with transformers and tank
> caps that are several times larger than my secondary!
>
> Anyone's links or shared experience would be appreciated.  Although I'm
> proceeding down the SSTC route otherwise, I'd like this little project
> to be a small-scale version of (something like) the "classic design".
>
> Cheers
>
> M
>
> --
> Matthew Smith
> KBC, PO Box 150, Kadina, 5554, S. Australia
> Ph: (08) 88 212 395  Fx: (08) 82 190 157
> http://kbc-dot-net.au
>
>
>
>