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Old August 3rd 09, 09:14 PM posted to rec.radio.amateur.antenna
JB[_3_] JB[_3_] is offline
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First recorded activity by RadioBanter: Apr 2008
Posts: 543
Default Counterpoise for an end-fed wire antenna

You are correct. I should NOT have given a simplified response to a
simple question.
Your technical answer is a much better response tho I suppose I could
have made mine as technical so that he would not ask questions any
more! Good point about common mode. That should screw him up as well
as other things that you inserted with respect to how does one connect
to an antenna. We could ask him I suppose how many wires he intends to
connect to his intended antenna feed point, and if it is not two then
question how he intends to measure the impedance for matching
purposes. Yup, I could have done a better job.


Art,

See the original post asking: "How to route feedline from dipole".
If he were to let his coax hang straight down from the feed point, there
would be no discussion. In asking about dressing the coax along one of the
dipole legs, Common Mode currents are induced on the outside of the shield
and there is no longer a simple discussion. His further questions arise
out of trying to deal with that problem of not being able to let his coax
hang where it wants to.

Also, one leg of his dipole will be over the roof and the other in the
clear, so one leg will be detuned to throw more trouble into the mix.

To get him on the air quickly, a tuner is desirable. If he has that, he
might as well make a multi-band antenna where his feed point location is
elsewhere. I think he got that because then he asked about counterpoise and
ground, which is the next step in the evolution of that type of system.

This is a specific technical problem.