Martin: There are a lot of caveats to your question about your Beverage
antenna however I have a couple of thoughts.
First to compare to your TX vertical I must guess at an approximate 4 Db
figure of merit (RDF) for the TX antenna. Estimate based on my own antennas.
Second a 240 meter Beverage gives an RDF of about 12dB. This says that there
would be a theoretical 8 dB. improvement in SNR at the very best angle of
reception of the Beverage. Also assuming no point source interference issues.
We all know that signals almost never arrive at the best angles so I would
guess at an improvement of about 1 s-unit (6 dB.) in SNR generally speaking in
front of the antenna. Beamwidth is about 60 degrees.
However, I would suggest that you go out with a portable receiver near the
line and make sure that the telephone line is not carrying interfering signals
like DSL gone awry before you go to all the trouble of installing the antenna.
And also if the farmer is going to turn off the electric fence why don't you
just petition him also to let you feed and terminate the desired portion of it
like a Beverage temporarily. Pop in a couple of inline insulators and then
short them out when you are done. Sure would save you lots of work and a 1
meter high Beverage will work pretty well.
Good Luck Lee K7TJR Oregon
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