Re: I Need some Help.

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

These ceramic disk caps won't work all that well... They're kind of lossy
and not really up to handling significant RF current.  They also have a
pretty high temperature coefficient, so as they get hot they change value,
making your coil go out of tune.

However, they ARE cheap, so for fooling around they might work, as long as
you're aware of the limitations...


For what it's worth, that's a pretty big transformer to drive such a little
coil.. 





Tesla list wrote:
> 
> Original poster: "Vivek Babtiwale by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dr_vek-at-yahoo-dot-com>
> 
> 
> .001 UF 10 KV AXIAL CERAMIC DISC CAPACITOR
> CAT# HVD-102
>     $ 1.00 each
> --- Tesla list <tesla-at-pupman-dot-com> wrote:
> > Original poster: "by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <TeraJoule-at-aol-dot-com>
> >
> > ~Hello
> >        I have been working on my first coil for a
> > few weeks now.  I finished it
> > and turned it on.  There was no discharge off of the
> > Sphere on the secondary.
> > However there is a little arc (and I mean little)
> > when I place a piece of metal
> > next to it (something like a screw driver).  I've
> > been wracking my brain to try
> > and fix this problem and I was wondering if one of
> > you fine gentlemen would
> > help me.  I think it is something with the frequency
> > of my circuits. I believe
> > they are mismatched...
> >
> > The Dimensions of my coil are as follows:
> > Secondary uses 30 gauge copper wire that is wrapped
> > around a PVC pipe 7/8 in.
> > diameter and 8.25 inches tall. (about 700 turns) the
> > sphere on top is .75
> > inches in diameter.
> >
> > The transformer is 9000 V NST and 30 mA.  It's rated
> > at 120 V.
> >
> > The capacitor has 17 sheets of 5.5 in. x 6 in.
> > separated by .1 in. window pain
> > glass.  (I don't know the dielectric value.)  If it
> > makes any difference, only
> > 4 inches of the foil overlaps for each of the plates
> > ( a 6 inch x 4 inch plate)
> >
> > The spark gap is non-rotary and can be adjusted to
> > any distance it needs to be
> > at.
> >
> > The primary is helical and is basically 5 turns of
> > wire.  3.5 in. in diameter,
> > spaced 1 inch from eachother.  (I would be most
> > willing to change this or the
> > capacitor.)
> >
> > I would be forever grateful if someone could help me
> > work out the flaws in this
> > design.  Thank you very much for all of your time.
> >
> > Sincerely,
> > Alex
> >