Re: Testing capacitors (fwd)

---------- Forwarded message ----------
Date: Mon, 27 Jul 1998 17:19:38 -0700
From: Terry Perdue <terryp-at-halcyon-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: Testing capacitors

(I posted this recently, but received no replies, except one asking me not
to post in HTML, which may have made it unreadable to some. Now that I've
figured out how to turn that off, I'll ask my dumb questions again):

I posted a message a few weeks ago about some oil-filled 10nF 80kvdc "xray
machine" caps I have, asking if they might be suitable for TC use. Several
people thought it was worth a try, but suggested a safety enclosure, in case
they overheated and exploded. My question is this:

Is there a way I can test them for suitability before building the whole
system? I have a NST, and could fashion a temporary spark gap. I'd like to
run a minimal system long enough to give me confidence that these caps will
survive before going any further, as I'm not interested in rolling my own

Two other questions:

I had hoped to use 10" diam acrylic tubing for the secondary, but at $40/ft,
may have to use PVC. But I'm considering getting some sheet acrylic and
melting it around a form, possibly in half-cylinder sections, then cementing
them together. I've been pretty successful forming plexiglas in this way in
the past, and assume that it is the material of choice. Has anyone tried
this? (I'm assuming that the sheet stock is much less expensive.)

Finally, I think I read that if the spark gap is close enough to the
transformer, secondary RF suppression isn't necessary. Is there agreement on

Thanks for your comments.

Terry Perdue