The 'rolling ball' theory of lightning protection is an ancient method that
said basically that you take a ball (in your mind of course) as tall as a
vertical object and roll it around the object and any area inside where the
ball rolls is safe from lightning... basically it is something like a 45
degree angle from the highest point down to the ground, also known as the
'cone of protection'. this has been shown to be untrue many times,
photographic evidence of lightning hitting sides of buildings, near the base
of towers, the bottom wires on power lines, and many other spots that would
be 'safe' according to the rolling ball theory exist.
David Robbins K1TTT
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
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> From: email@example.com [mailto:towertalk-
> firstname.lastname@example.org] On Behalf Of email@example.com
> Sent: Tuesday, July 04, 2006 15:33
> To: firstname.lastname@example.org
> Subject: Re: [TowerTalk] Water tower omni
> Can you tell me more about the 'Rolling Ball' concept and lightning?
> I've never heard of it.
> Someone, I think it was in the forum, said that lightning protection is
> like an insurance policy. The more you spend, the better your
> protection, but you couldn't guarantee that you weren't going to get
> taken out. Of course, there's the people who say that's silly, that
> professional broadcasters have to stay on all the time, through
> lightning hits etc. Of course their equipment is a bit heavier and a lot
> more expensive the typical equipment I install.
> The side tank mounting has been, at least so far, a relatively safe
> method. I think we've had one side tank mounted antenna taken out at
> most. (Actually the antenna wasn't taken out, but the coax as it was an
> old installation that wasn't properly grounded, if I remember correctly.)
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