I'm with Chuck on this one.
If you consider the fact that a strike has just traveled several thousand
feet to hit your antenna, trying to "isolate" the coax is probably an
exercise in futility - another few feet from the end of your coax to ground
is nothing.
Further, if you have your coax inside the shack, and either disconnect it
and leave the coax sitting inside (especially if you are in a basement with
a concrete floor), or feed the end outside your window but still have part
of the coax inside the shack, you may indeed prevent a strike from hitting
your radio - but lightning is as hot as the surface of the sun, so you may
loose you equipment in the ensuing fire!
Best to ground the coax, the tower, the rigs, and so forth - thoroughly. One
ground rod ain't NEAR enough!
73...... Jim N1RUI
-----Original Message-----
From: Constantine, Charles <charles.constantine@lmco.com>
To: 'towertalk@contesting.com' <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Thursday, April 01, 1999 9:53 AM
Subject: [TowerTalk] RE: Antenna Grounding
Subject: RE: [TowerTalk] Grounding antennas?
To: <towertalk@contesting.com>
Date: Mon, 29 Mar 1999 09:29:55 -0800
From: Chuck Constantine <Charles.Constantine@lmco.com>
To: towertalk@contesting.com
> [TowerTalk] Grounding antennas?
>
> Ted Leaf (tleaf@hotmail.com)
> Mon, 29 Mar 1999 02:23:50 PST
>
> * Messages sorted by: [ date ][ thread ][ subject ][ author ]
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> * Previous message: rick@area.com: "[TowerTalk] Re: ground radial
fields"
>
> Hi Guys,
>
> Just a thought on the previous post of whether to ground or float the
> coax of a wire antenna when not in use.
>
> If you ground, you may be attracting a lighting strike by offering an
> easy path for discharge.
> If you float, the discharge may find a more convenient direct path to
> ground elsewhere.
Reply: I disagree, Lightning comes down in "Stepped Leaders". Each Stepped
leader can be on the order of hundereds of feet per step. As the leader
comes
down it will take the path which has ionized for it......
------------------------
... Bottom line is grounding or isolating an antenna is NOT going to prevent
a
Lightning attachment. Grounding can actually decrease the chance of
attachment
by preventing static buildup which can generate upward streamers and also
provides a preferred path to ground. No matter what if you take a direct
attachment theres going to be damage. You can probably kiss your coax
goodbye
as the lightning will probably arc over through the dielectric on its way to
ground and you will have to replace the wire antenna anyway cuz the
instantanious current and the inductance in the wire will cause it to
"Vaporize"
it into oblivian.
73 Chuck Constantine KR6C
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