[Antennas] Dumb question?

Mon May 18 13:09:10 EDT 2009

Let me share my observations at my station. My main tower is 110 ft
plus about 15 ft of mast. The top of the mast has either had a somewhat
pointed cap or the cap and a porcupine. I don't get many lightning
storms. When a storm approaches one can clearly hear a discharge
(click, click, click, ...) from either the mast cap w/o the porcupine or
the porcupine.
A couple of years ago I did get a lightning strike. The strike instead
of hitting the cap or porcupine, hit the reflector of the 10 meter beam
which is mounted about 5 feet below the top of the mast and 12 feet out
from the mast. I am pretty sure it hit the reflector as there was a
large 'burn' mark on the reflector tubing, and damage to the reflector
to boom insulator where the strike apparently jumped to the boom which
of course is grounded to the tower.
Doug
I'll run the race and I will never be the same again. 
-----Original Message-----
From: antennas-bounces at mailman.qth.net
[mailto:antennas-bounces at mailman.qth.net] On Behalf Of
don_keith at bellsouth.net
Sent: May 18, 2009 9:25 AM
To: Antennas at mailman.qth.net
Subject: [Antennas] Dumb question?
Joe K2XX:
The URL of the article you mention is:
http://www.lightningsafety.com/nlsi_lhm/magic.pdf
It is, as you note, very well written. Nature seeks balance in
everything. That is why water runs to the lowest level, the strong eat
the weak, and lightning takes the best path it can find to equalize the
charge when it strikes. I sometimes wonder if lightning protection
should be either extremely well done or very poorly done to be
successful. 
Here's what I mean. If you have a system that is effective in allowing
Nature to balance dissimilarly charged patches of atmosphere and earth,
then you dang well better have a wonderful way to handle the resulting
strike that you will be likely to attract.
73,
Don N4KC