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Old September 20th 04, 01:17 PM
Dave Hall
 
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On Mon, 20 Sep 2004 00:33:28 -0400, "Leland C. Scott"
wrote:


"Glenn S." wrote in message
.. .

Which omnidirectional base antenna will put out the least TV
and telephone interference in the neighborhood?


It doesn't depend on the antenna almost at all. The main cause of
interference is from three sources. One a dirty transmitter, the second is
from receiver front end over load, and the third is from RF getting in to
the electronics directly.


That's not entirely true. The antenna DOES have a part to play in the
whole mess. Some of the "stick"-type antennas, such as the A-99, have
poor decoupling and this allows for significant coaxial shield
radiation. Some of these antennas also concentrate a good portion of
their near field radiation in places where it would exacerbate front
end overload or couple R.F. into house wiring.

An otherwise clean transmitter coupled to an antenna with the above
characteristics can cross the line between no RFI and significant RFI.
In some cases, this can be mitigated somewhat by moving the antenna
(usually raising it) to another area, where it's radiation will not
couple as much R.F. into neighboring premises. A better solution would
be to run an antenna with ground plane radials, such as a Sigma 5/8
wave or similar.

Dave
"Sandbagger"
http://home.ptd.net/~n3cvj