Any attempt to provide ground for lightning protection MUST be outside of
the structure. No exceptions unless you want a visit from the local fire
department. In which case, they may be able to save the lot.
As to RF ground, it usually is located at the base or common point of the
radiating system. Example: vertical, or end fed wire or other unbalanced
antenna configurations. Balanced feed and coax fed antennas {beams} do not
require any form of RF ground. Trying to ground the station for RF is
typically futile due to the length and inductance of the conductor used for
grounding.
73
Bob, K4TAX
----- Original Message -----
From: "Gary Hoffman" <ghoffman@spacetech.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Tuesday, November 29, 2005 3:37 PM
Subject: Re: [TenTec] Station and AC Ground
>
The first (RF) is somewhat hopeless, as was pointed out, because a
real (broadband) RF ground has to be very short, say not more than
1/10 wavelength, to avoid reactive and resonant effects. That means
shorter than 1 meter for 10 meter operations, etc. That's not
practical in most installations. You don't really need a "true" RF
ground, if your antenna system is balanced properly - no common mode
RF on the feed lines, etc.
Or....a half wave ground wire, to repeat the low impedance at earth right
at
the radio.
And, since lightning is RF, I feel that a real RF ground is important,
even
for lightning.
73 de Gary, AA2IZ
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