[BC] AM transmitter lightning sensitivity issue

[Ron Nott]

Gary, your analogy of the HF Yagi appearing to be a big capacitor 
plate is very good.  For many years I had a Moseley TH6DXX (big HF 
Yagi) up 70' high plus we are on a New Mexico mesa about 100' above 
surrounding terrain. Before cranking it up, I placed about 30+ 
strands of #18 stainless steel wire projecting about a foot above the 
mast top and flared them out. Retained them with a SS hose 
clamp.  Did the same thing on each end of the boom.  Never had a 
trace of lightning damage.  However, when there were nighttime 
lightning storms in the 13,000'+ mountains about 45 miles north, each 
time I saw a strike there was instant crackling from the SS wires on 
the antenna.  This indicates that the electric field can extend 
horizontally for many miles outward from a storm.

A person can do lots of DIY lightning prevention with a roll of #18 
SS wire and some SS hose clamps.

Ron Nott - K5YNR

----- Original Message ----- From: "Gary Peterson" <kzerocx at rap.midco.net>

It seems to me that there must be a point (no pun intended) where the number
of sharp points begins to mimic the surface of a smooth object, such as a
sphere.

This was my thinking on my amateur antenna installation.  I have a very
large five element, HF Yagi on top of a 65' tower.  I felt that this would,
electrically, resemble a flat, conductive plate.  Therefore, I have 6' of
mast, with a very sharp point, projecting above the antenna's boom.  There's
lots of visible corona activity up there when storms are building.  No
evidence of a strike in the last twenty years.  With our low humidity, we do
get plenty of potent lightning.  Maybe I'm just lucky.