> I will not give up my view that half the battle is in prevention of a
> strike. If it was not a valid point, why then is it that guys with properly
> protected metal structures up in the air do not get struck, yet the chimney
> of their neighbor next door does. It all has to do with charge build up and
> being able to eliminate it. The properly configured tower system does that.
> They guy next door with the metal chimney flue probably doesn't.
The answer is simple, but hard to see.
When a tower is properly grounded it conducts the (usually electrons)
ground current, a massive ground current moving under but of opposite
charge to the airborne `cloud of holes' moved along by the wind, up
into and charging the metal of the tower.
If a stroke occurs all of these and all free electrons in the metal
`go up' in the stroke. Additional electrons come across the surface
of the ground crossing your house grounds, (telephone, cable TV,
power etc.) dropping a few thousand Volts killing your new VCR
and answering machine (being connected to two different grounds) to
satisfy the air born cloud's requirement. Bond every ground in your
house together with AWG #4 or heavier wire to minimize this damage.
The resistance of the tower and it's grounds are low. Little I*R drop.
The resistance of the chimney next door is very high and the wind blows
the strike from the tower to the chimney. POW
I disagree with most remarks on the subject, I believe an ungrounded
insulated tower (including the guy wires) will never be truck by lightning.
--
73 (= Best Regards) de: Ron ka4inm@tampabay.rr.com
100% Slack. since July, 1997 (still free!) SENT D&T are UTC
Visit my HAM Web SITE at: http://www.qsl.net/ka4inm
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