Re: Tube coil capacitors

To: tesla-at-pupman-dot-com
Subject: Re: Tube coil capacitors
From: Brandywine <brandywine-at-writeme-dot-com> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Thu, 18 Feb 1999 16:57:35 -0700
Approved: twf-at-verinet-dot-com

Carl,
   I intend to use 4 833A's. I have 2 high voltage power xfmrs--a 4600 V
Collins Plate xfmr only rated for 1150 kVA but, considereing it's weight,
100+ lb, probably capable of many times that; and a 5 kVA, 14.4 kVac pole
pig. John Freau has put as much as 7 kVac on the 833A. I don't think I'll go
that high, but you get the idea of what kind of power we're talking about.
   Something like your Erie cap looks like an interesting candidate. You said
you went through several caps before finding ones that worked well. Which
types performed poorly? Thanks for your interest in my project Carl.
Dave H.

Tesla List wrote:

> Original Poster: carl a willis <cwillis4-at-juno-dot-com>
>
> >Original Poster: Brandywine <brandywine-at-writeme-dot-com>
> >
> >Guys,
> >   I'm in the process of building a high power tube Tesla coil. I'm
> >looking for a source of capacitors, preferrably used, for this
> >project.
> >Any ideas?
> >Dave Hartwick
> >
> Dave,
> What do you mean by high power? I have just finished an 833A tube coil
> that can produce a 20" spark and uses a "doorknob" capacitor (for the
> plate tank) that does not heat up much at all.  It took several
> capacitors before I found one that worked well. I bought it new from RF
> Parts co. for $14, which is better than many used prices I have seen for
> these. Its an Erie 1900 pF / 15 kV capacitor. I use it in parallel with a
> 100 pF air variable immersed in mineral oil for a total of ~200 pF. For a
> coil with the lowest loss, a big air variable in mineral oil will
> probably work well. I have heard that old transmitting mica capacitors
> are well suited to tube coils, but they're expensive and hard to come by.
>
> -Carl