PET as dielectric

From: 	Per Niva[SMTP:pna-at-pp.gellivare.se]
Sent: 	Tuesday, August 26, 1997 7:21 AM
To: 	Tesla List
Subject: 	PET as dielectric

Hello everybody!

Somebody, methinks it was on this list, mentioned something 
along the lines of "if somebody offers you PET as a dielectric for
tesla work, run a mile in the opposite direction". He didn't 
mention why, though, and the plastics reference works I've been
able to use didn't either. I guess it's about RF lossage or 
something? Otherwise PET (polyethene terphtalate) seems to
be close to ideal as capacitor dielectric?

Today I finished off the primary tank circuit. When I run it
without a secondary (it will be finished later), 

... oops, people told me this is a Bad Thing ...

the spark gap is turning out those famous sounds and UV light, 
and the safety gap fires occationaly. BUT, the capacitor bottles 
are glowing from quite heavy corona. This seems to come from 
the water/oil interface, both inside and outside the bottles.

The question is, is this due to some RF loss in the PET plastic?
(PET is polyethylene therphtalate.) Or due to something else?
There are no corona displays when I run things without the
primary coil, ie. at lower frequencies.

The cap is six 2-litre PET soda bottles filled up to the end of
the cylindrical part of the bottles with salt water, and on top
of that about an inch of mineral oil. They are standing in a
plastic box filled with salt water to the same height as in the
bottles, and an inch of oil on top of that too.

Any comments appreciated,


pna-at-pp.gellivare.se                 +46 (0)970 20976
"Beware - the world will never be the same again..."