[Elecraft] OT: Open wire feeder cautions

[Ron D'Eau Claire]

Long ago I used ceramic cone insulators too, but for decades I've used
simple 1/4" acrylic tubes. They insure that nothing in the wall comes in
contact with the feed line and eliminate the mechanical joints at either end
of the feed-through (I solder the feed line connections). A small 1/4" hole
accommodates each tube and extend about 1/2" out of both sides of the wall.
A few wraps of tape around the ends keep them from sliding out of place.
They are not very visible either. 

I've used acrylic in a number of very high RF voltage insulator applications
with no sign of failure. 

There's a reason why we put fences around commercial transmitting antennas
and take care to avoid touching antennas on ships! RF burns are terribly
painful. They're deep and they're nasty. 

Many of us O.T.s learned about them using a pencil to draw an RF arc from
the plate cap of a transmitting tube "for fun" :-) I can still remember the
deep, throbbing pain from a little black burn that lasted for days right at
the spot where the metal eraser ferrule was touching my skin the very LAST
time I did that, Hi!  

73, Ron AC7AC