[TowerTalk] spider balls

[Keith Dutson]

Here is an excerpt from one of those documents at
http://www.lightningeliminators.com/technica.htm.

"Protecting a premise against direct lightning strokes by preventing
lightning stroke is not exactly a new idea. It was Franklin's original idea
that he could dissipate the thundercloud electricity by installing the
pointed iron rod, which would quietly conduct the electricity away. However,
he changed his mind after his lightning rods were hit by lightning instead
of preventing the strokes."

This seems to show that spider balls will not do what you are thinking.

Later in this document is a discussion of space charges near the ground that
are built up just before a strike.  The design criteria to prevent a
lightning strike is not to prevent it, but to distribute it such that it
does not harm delicate electronic components with EMP.  One has to ponder
the role of a spider ball in this design.

Keith

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Jerry Keller
Sent: Wednesday, July 28, 2004 9:42 PM
To: Tom Rauch; kk9a at arrl.net; TOWERTALK at contesting.com
Subject: Re: [TowerTalk] spider balls

Tom wrote: "The data was derived from a map of recorded lightning hits, and
comparing concentration of hits to heights of towers. One thing specifically
discussed in these links was a water tower that was erected near a house.
They were very good in their methodology, so I have no reason to doubt the
accuracy."

Tom... I took a look at the data on the two sites you mention. 

The first one reports how well grounded lightening rods curbed the damage
the wind generator towers were experiencing from lightning strikes, bringing
the damage to near-zero incidence. But I saw no data that addressed the
number of lightning strikes before or after the installation, they just
talked about damage mitigation. I saw nothing there that says how often the
ground around the towers was struck vs how often the towers were struck. 

The 2nd site speaks to geographical influences on lightning strike density,
and it's on a large scale... covers areas much larger than an antenna field.
It also doesn't say anything specific that I could find about the topic we
had under discussion, just general trends. There's lots of the maps of you
mention, but I didn't see anything "comparing concentration of hits to
heights of towers" as you stated. 

And, I didn't find anything on the Polyphaser site (other than grounding, on
which everyone agrees) that deals with pre-strike means to lessen the risk
of a strike, just methods and products for post-strike mitigation.

But perhaps I perused them too quickly. I'm sure if you relied on specific
data it must be there somewhere. Could you please extract the pertinent data
for me? Maybe your eyes are sharper than mine.

See, all due respect and no offense intended, I don't think you (or others)
have any more real, hard, pertinent, reliable, data on pre-strike factors
than I do, yet you (and others) insist on making definite, specific,
authoritative pronouncements about the subject. I don't say you (or others)
are wrong, just that you (like me) don't really know for sure, and one can't
convincingly refute ideas without presenting some hard, pertinent data. 

Here's a site that seems to have hard data to support its products, which
look remarkably like "spiderballs" and are in wide industrial use as a way
to lower the risk of a damaging strike. They offer pre-strike risk reduction
with products approved by the Underwriters Lab. I have no independent
knowledge of whether or to what degree they might work, but I seriously
doubt this company would have been in business for 30+ years if their claims
were just hooey. 

http://www.lightningeliminators.com/technica.htm 

73,  Jerry K3BZ
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