RE: Newbie cap and topload questions

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dave Halliday" <dh@xxxxxxxxxxxxxx>

Welcome aboard!

If you visit the list archives and search for MMC you will find what is
needed.

http://www.pupman.com  -  look at the left sidebar for "Searching -
Search the site including the list archives"

There are a very few caps that work but they work so much better than
any similarly priced alternative that it would be a real shame not to
use them unless you like poor performance and tossing money out the
window.

Specifically, you want the Cornell Dubilier 942C20P15K which is 0.15 uF
at 2000 VDC.  Other caps have been already tested to destruction by list
members and this specific cap keeps turning up as the best to use bar
none.

RELL sells them for about $2.45 each but there is a fairly large minimum
order.

People on the list (Paging Dr. Resonance!!!) have them for sale to list
members.

Good luck!
Dave

> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Saturday, January 07, 2006 6:54 PM
> To: tesla@xxxxxxxxxx
> Subject: Newbie cap and topload questions
>
>
> Original poster: jvillecheesehead@xxxxxxxxxxxxxxxx
>
> Hi,
> I'm a first time coiler and it took until now for me to
> finally discover how
> useful this list was.  Anyhow, I am using a 15kv 20mA nst and
> have wound my
> secondary of 4" diameter 20" height with 800 turns of 23
> gauge wire.  My
> question is about a couple options with caps.  First, I am assuming
> this 35,000V
> .005uf cap from Electronics Goldmine for $2.75 is not
> suitable for tesla coils
> as the site claims and wanted to confirm this.  Here is a link:
> http://www.goldmine-elec-products.com/prodinfo.asp?number=G155
> 89&variation=&aitem=72&mitem=91
>   My other plan was to use this Phillips 1600V .047uf cap that runs
> for a buck a
> piece at the same site:
> http://www.goldmine-elec-products.com/prodinfo.asp?number=G148
> 32&variation=&aitem=67&mitem=91
>   According to an excel calculator, I believe using Terry Fritz's
> data, the best
> reliability/price point would be 2 strings of 19 of these
> caps.  Upon reading
> some other posts it sounds like some people push them harder
> without any issues
> and was wondering if anyone had an opinion on this.
>
> I also had another quick question about the topload.  For
> some reason in my
> planning (which was a few months ago, couldn't work on the
> coil while I was at
> college) I decided to use a toroid with 3" diameter Al
> ducting with a total
> diameter of about 10 inches.  Using Barton Anderson's JavaTC
> calculator this in
> combination with my other components results in a 390kHz
> resonant frequency.
> The size and frequency differs from many of the coils I have seen
> online and was
> wondering if there is any problem with using it.
>
> Lastly, I thought I would share a picture of my spark gap that
> includes a simple
> modification to the Richard Quick design that allows for increased
> adjustability.  Thanks for the help!
>
>
>
>