Re: Suitable capacitor dialectrics

["Bert Hickman" <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "Garth van Sittert" <garth-at-mediasupplies.co.za>
> 
> Hi All
> 
> I have searched the archives and couldn't seem to locate any posts that
list a
> set of suitable capacitor dialectrics that can be used in the primary
> capacitor.  It may be useful if anyone knows of a couple to list it.  So
far I
> know of polypropylene, polyethylene.  Vinyl (PVC) is a no no.  Learned from
> experience.  Got a 42nF 10kV homemade vinyl cap though.
> 
> Are polyester caps suitable for MMC's?  And what is an EMMC?
> 
> Many thanks
> Garth (From the bottom of Africa).
> 

Garth,

Stick with polypropylene or polyethylene. Although polystyrene is also a
very low loss dielectric, it is not compatable with mineral oil. Some
coilers have used polycarbonate and acrylic, but these are 
significantly lossier. Others have experimented with Kapton and teflon,
but these tend to be prohibitively expensive for larger caps. Avoid
using mylar (polyster) for RF applications because of excessive
dielectric losses. 

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-com
Web Site: http://www.teslamania-dot-com