Ralph Mowery wrote:
"Chris" wrote in message
...

Hi,

I'm currently having to build some high-voltage capacitors for an auto-ATU
that I'm building. The capacitors are made from interleaving brass shim
with some kind of dielectric. It was suggested that the dielectric was

made

from a triple layer of polyethylene sheet (ie freezer bag) stuck together
with DC4 grease to exclude any air. However, this seems a messy approach
and some engineer friends suggested that instead I use overhead projector
transparency. I found that a double layer of this transparency worked to
give me reasonable capacitor values with a reasonable number of plates per
capacitor.




Look for some Kayton made by Dupont. It is a high voltage plastic like film
similar looking to the mylar sheets. It is especially made for applications
like you want.


sometimes sold as an insulator in sheets for transistors