[Antennas] Radials

Sat Apr 18 06:54:03 EDT 2015

Your electrician is right, don't bother with more radials or added ground
wires. I would bury the radials you have, but just because I would hate to
waste the wire, but they aren't going to help significantly for electrical
safety or lightning protection. Leaving them on the surface definitely
won't help either case, for electrical safety or lightning protection you
want radials buried as deep as possible to provide them the most volume to
dissipate any current they carry. Putting them on the surface is the worst
case as they lose half the volume to start with since they can't dissipate
charge into the air and they have poor contact with the soil. If you bury
them at least a few inches down they at least get better contact with the
soil but still only have about half the effectiveness they would have buried
3-4' down.
As far as for an rf ground, surface radials would help efficiency if you
were going to feed the tower as a vertical, but then you would want many
more than 3 and near the surface instead of buried. Surface or buried
radials will not help inverted V's or Yagis.
David Robbins K1TTT
e-mail: mailto:k1ttt at arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: Antennas [mailto:antennas-bounces at mailman.qth.net] On Behalf Of Mike
Reublin NF4L
Sent: Saturday, April 18, 2015 00:04
To: antennas at mailman.qth.net
Subject: [Antennas] Radials
I have a 70' tower with an inverted-L for 160M and a 1/4 w sloper for 80M.
The tower base has 8 yards of concrete and a lot of rebar. There are 3 #4
copper wires, with one end attached to each tower leg, then into the
concrete, attached to the rebar then exits the concrete just under ground. 
The original plan was to put 3 ground rods along each wire. My electrician
told me that as far as safety grounding goes, there was no benefit. The
tower/base megged at 4 ohms.
The wires are currently rolled up at the base of the tower. If I straighten
them out and staple them to the lawn, do they then act as radials? Would it
be feasible to attach more radials to these where they emerge from the
concrete, so as to avoid having the top of the concrete pad awash in wire?
73, Mike NF4L
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