Stuart.
What you say makes sense. Does it also make sense to fan radials (4 to
6 at 20-30 ft in length?) off one end of the house. This would prevent
discussions with neighbors. It is not clear to me how such a ground
would affect the R7 pattern, which is also on that side of the house. It
also sounds as though I want to run a connection to the AC ground in the
basement.
Another thought I had was to place the largest knife switch I can find
in the ground system where it leaves the house. Then I could easily
break the connection there.
I have not disconnected my antenna system except when I go on vacation.
Luck has been with me so far, I guess. I have given the subject some
thought as I am in the process of building a remote antenna switch so I
may utilize the G5RV I have disconnected but left up when I reinstalled
my R7. The R7 is not grounded, per a discussion with W1JR at a
Hamfest, although the base sits on a 10 ft pole which is u-bolted to a
length of rebar driven into a drilled hole in the ledge. As you
mention, the ledge is probably not the most conductive connection.
John / WA1JG
On 1/25/2012 3:23 PM, Stuart Rohre wrote:
John,
It would be a waste of time to drill into rock for an RF ground, unless
the rock was iron ore, or silver ore!
What hams need to do with this case, which is very common, sometimes not
even rock but caliche like I have, or other poorly conducting soil, is
to lay out quarter wave radials or a counterpoise wire at least. Run
the radials in all directions you can like a crow's foot. This is also
called a crow's foot ground.
You might zigzag some wire in that low crawl space, to fit the area.
Just make sure you also bond the radio ground(s) to the AC electric
safety ground to avoid setting up a difference of potential in case of a
strike on your antenna.
I would unplug all my radios from feedlines, and AC in such a poor
ground environment, when not in use and/or you are not home.
The best surge suppressor is not going to help much in case of a direct
strike, and at your location the lightning has no easy path to take.
Stuart Rohre
K5KVH
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