If you are trying to achieve a good lightning ground, this would be
insufficient.
Several 50-75 foot-long radials, preferably of at least 1.5"-wide solid copper
strap (2/0 would do, but 4/0 is better, if you must use wire; however, strap's
far superior to wire) emanating from each leg with a ground rod at beginning and
end (the starting rod can be common for the several radials). There should be
intermediate ground rods as well. If you have good conductive soil, they should
be
spaced twice their length apart; i.e. 10-footers should be 20' apart. Since
most folks
don't have this type of soil, nor can ascertain what they have, it's best to
use a multiplier
of 1.5 and if you know for a fact the soil's poor, a factor of 1 to 1.25 would
probably be in
the ballpark.
A single point ground should be established where the cables enter the
building. This
should include the suppressor grounds, equipment grounds, and the utility
ground(s). For
best results, all I/O's should be protected: RF, ac, and telco. If the tower is
less than about
75' from the building, a single strap (with no intermediate ground rods) should
go between
the tower and the single point ground; however, this isn't an absolute
necessity.
Last, but not least, install a #2 Iron golf club at the top of your tower. As
Lee Trevino once
said, "Not even God can hit a #2 Iron." :)
73,
Bob Wanderer AA0CY
Senior Applications Engineer
PolyPhaser Corp.
work e-mail: bobwanderer@polyphaser.com
----------
From: Steve Weisbrod[SMTP:steve@gamecash.com]
Sent: Tuesday, July 08, 1997 7:25 AM
To: deshelto@juno.com {MHS:deshelton@juno.com}; towertalk@contesting.com
Subject: RE: [TowerTalk] Grounding your tower and
I put six 8ft ground rods around my tower. If I were you I would put in
at least six. They are placed at 120 degrees apart. Then the second set
six feet away from the first set.
73 Steve W8GAZ
----------
From: 'deshelto@juno.com <MHS:deshelton@juno.com>'
Sent: Monday, July 07, 1997 7:07 PM
To: steve; 'towertalk@contesting.com'
Subject: [TowerTalk] Grounding your tower and sta
Original Subject:
[TowerTalk] Grounding your tower and standing off your coax?
I have recently put up a new tower, 50ft of 25G, beside my home with the
tower bracketed at 21ft with a house bracket on the top sets a Force 12
C4 at about 50ft. I have grounded the tower by driving an eight foot
ground rod into the ground about 3ft away from the base of the tower. My
problem is this, my home sets on a high plateau with a limestone rock
shelf only a few feet below the ground, about 5 to 10ft depending on your
location. I was only able to get the 5/8" X 8ft grnd rod about 5ft into
the ground before hitting rock. I proceeded to take a hacksaw and cut it
off at ground level and drive the remaining 3ft into the ground a few
feet off to another corner of my 1 sq. yd . of concrete. I am using #6
copper stranded wire to connect the tower legs to the grnd rods. My
question is this, is this satisfactory grounding for a tower in my
situation?
Next I have two runs of RG-213/U up the tower for the beam currently I
have the coax mounted to one of the legs of the tower with draw-tights,
is it better to have the coax cable hanging off to the side with a coax
standoff of some type?
Any reply is greatly appreciated.
73,
David E. Shelton KE4FPS
Amateur Radio Transmitting Society of Louisville, KY
deshelton@juno.com
KE4FPS@WD9AGK.#SIN.IN.USA.NA
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