On Tue, 15 Feb 2005 21:44:34 -0600, me wrote:

After many years of experimenting with coax fed wire antennas I am
taking my first plunge at open wire line.

To get into shack, I need to go through exterior steel siding,
exterior wood siding & plywood, a layer of insulation, then interior
sheetrock and wood paneling. Assume I need about 4-6" of safe
feedthrough so that standoffs can be mounted on the walls oustide
and inside the shack.

I generally run 100 to 1500W output...at full legal limit probably
3KV on the feedline...am not crazy about the idea of setting my house
on fire due to HV arc over.

Am looking for the old style porcelain feedthrough isnulators, but so
far have not found same.

Local Home Depot has thin PVC tubing (as in sink/toilet stems), vinyl
tubing, welding rod tubes, etc. What are the dielectric properties of
these, and the high voltage breakdown voltage...???

Seems like glass, porcelain, or ceramic tubing would be best
feedthrough insulator, but where to find?

I use ceramic feedthrough insulators on a piece of board in the bottom
of my window to bring 450-ohm line indoors. I got the insulators from
Surplus Sales of Nebraska -- you can check their web site for info;
they have a pretty good selection of NOS in all sizes, tho' they ain't
cheap.

You may do just as well rigging something else, as per some of the
other suggestions here...

bob
k5qwg


Are any modern day materials found in Lowes or Home Depot safe from
arcing and also efficient for RF?

Thanks in davance & 73,

Dan (K0DAN)