"tom" wrote in message
. net...

On 8/30/2012 4:15 PM, Wayne wrote:


"KBa" wrote in message ...

# Hi all

# Problem exists how to get reliable insulation to split driven element
# and support rod which is exposed to RF voltage ?
# Fiberglass is told to be sensitive creating conductive coal brigdes
# which creates true resistive short at driving point ? (at least one
# fiberglass tubing is done so... gap was 2 inches )

# How to improve insulation ? Ptfe-shield over fiberglass rod, heat shrink
# tubing, varnish layer ?

# tnx oh6io

I'll leave the specifics of your question to the experts.

But, worth mentioning is that once you have selected a material, plop
some in a microwave along with something like a a container of water.
Then see if your insulating material stays cool.

Wayne
W5GIE

# Which is valid at the microwave oven frequency. Might be relevant at
# HF, or more likely, not.

# tom
# K0TAR

I'm sticking with the test being relevant at HF.
A material that does not heat up at microwave, would be unlikely to heat up
at HF.

At any rate, the test can be done for free.