K1TTT, speaks the truth:
<snip>
"First, there is no such thing as an rf ground. (time to put on the
asbestos underware!) Any RF you generate is looking for a path back to
where it came from. The most you can hope to do is provide as low an
impedance path as possible between components to keep rf potential
differences in the shack to a minimum.
As a corollary to the above, there is no such thing as a lightning
ground. Again, the aim is to keep the potential differences between
equipment as low as possible. The hardest part of this is usually
reducing the potential difference between power cables and 'grounded'
equipment... but that is a whole different thread.
As for testing your electrical safety ground the best thing is to have a
qualified electrician or your electric company test it for you. It
takes a special meter and measurement methods to do it properly. They
can also check your installation for you to be sure that all grounds are
properly connected to each other, that all applicable codes are being
followed, etc. In some areas electric companies may also be able to
install service entrance lightning arresters either free or cheap."
<snip>
Having an ESD ground on your antenna and tower is important. It may
help eliminate lightning strikes. Having a lightning choke on all
feedlines and rotor cables is important, too. I use a piece of
iron pipe, about 5' long, lying on the ground. This represents an
inductor, and tends to force strike current to ground. On distant
antennas, I also use said choke, en route to the tower base which
forms the central RF ground for the station. You have to consider
your feedlines and control cables as sacrificial.
Note that the equipment is NOT grounded, except via the power supply.
Chassis are tied together with short runs, but that's all.
Lightning protection is achieved by disconnecting all cables....antenna,
power, rotor control, remote switches, and computer ethernet, from the
equipment, at the entrance point to the house.
On the topic of electrical safety ground, there are plug-in circuit
testers which will indicate if the ground and neutral are properly wired.
and finally...in the ground is an illusion department....when you reach
1/4 wavelength from your central ground point, at the frequency of interest,
your equipment ceases to be at ground. It progressively moves away from
earth potential (at frequency) as the lead lengthens from zero. So 8' 3"
on 10 meters is too long. I prefer to avoid the potential for ground
loops by having antenna ground outside, and power ground at the box...and
nothing else.
N2EA
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