Pete makes a good point, up to a point. I do not believe "low
inductance grounding" is an issue in the single-point grounding
scheme problem. Reasonable attention with decent sized wire and
copper strap will suffice for the purpose of controlling the
problem of imbalances in potential at different ground points.
Low-inductance questions are mainly associated with RF grounding,
which is much different from tieing various gound points
together. Going from a second floor room to ground for the
purpose of a so-called DC ground is not much of a problem. Your
coax should be grounded near the ground out at the tower, and
maybe again just outside the house before coming up to the second
floor, so I don't think it would much of an issue as far as the
second floor goes. DC grounding and RF grounding problems are two
different animals.
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of Pete Smith
Sent: Tuesday, May 20, 2003 9:09 PM
To: Wes Attaway (N5WA); ww5l@gte.net; Kelly Taylor
Cc: towertalk@contesting.com
Subject: RE: [TowerTalk] grounding
At 08:52 PM 5/20/03 -0500, Wes Attaway \(N5WA\) wrote:
>Your story is a perfect example of why disconnecting feedlines
is
>not real good protection if proper attention was not paid to the
>overall grounding scheme of the station. The scenario you
>describe happened because single-point grounding was not in
>place. If you do not tie house electrical service and telco
>grounds to the tower ground and main station ground point then
>you will have many avenues that lead to trouble.
Agreed. On the other hand, investing hundreds of dollars in coax
and
rotator cable protectors won't help in this case either. It's
not just
single-point grounding, either, but single point low inductance
grounding,
which may or may not be possible depending on where your station
is
located. In a second floor ham-shack, with no possibility of
low-inductance grounding, I am comfortable that disconnecting
every
conductor from the tower is about as good as I can do. On some
level of
probability, I may still get damage, but I think this is a
legitimate,
cost-effective way of lowering the risk.
73, Pete N4ZR
The World HF Contest Station Database was updated 9 May 03.
Are you current? www.pvrc.org/wcsd/wcsdsearch.htm
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