When I could not tune out the ground impedance bumps, I installed a cheap
manual antenna tuner in the ground circuit leg. Then I got perfect
impedance matches at all frequencies into a long ground wire. This was in
addition to the normal automatic antenna tuner for the antenna. Tuning
was simple. Just adjust the ground tuner until the SWR was down to the
lowest you could get.

Larry DeMers



Bruce in Alaska wrote:

In article ,
"Tom Dacon" wrote:

I don't believe there's any need for an
electrical bond, since induction should do the job nicely.

The above doesn't take into account that we are dealing with
impedance in the frequency domain. By not having an good
electrial bond, you induce capacative coupling to additional
surface area for your RF Ground, That means that this coupling is
frequency sensative, and then the RF Grounding System will react
significantly different depending on the frequency being transmitted.
Autotune Antenna Couples have very specific tuning firmware, and this
code doesn't react very well to a highly variable Rg Ground impedance.
They are designed to operate against a FLAT RF Ground Impedance,
and the more bumps in the RF Gropund impedance the harder the tuner
has to work to tune the antenna, and the more phantom, and quirky
Low SWR points that the tuner will find, and lock on to.

Bruce in alaska
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add a 2 before @