On Fri,4/29/2016 3:30 AM, jimlux wrote:
I would think that two dipoles, with some sort of adjustable phase
combining network might be the optimum strategy. A dipole isn't going
to have good directivity for the main lobe, but can have a pretty good
null to place on an interferer.
Jim,
Eric, W3DQ, the guy asking the question, lives in DC on a fairly small
lot, so his options are pretty limited. I've visited his QTH and my XYL
and I have enjoyed their overnight hospitality. He's lucky to find space
and skylooks for one radiator, let alone two. :) So my reply is in that
context.
Eric -- another thing to consider is that a resonant 40M dipole in close
proximity to a 15M antenna can cause significant distortion of the 15M
antenna's pattern. I don't know if that's also true of a loaded 40M
dipole. I do know that the C3SS is sensitive to the Z of the
transmission line feeding it. Glen and I tried a 100 ohm choke on it
(bifilar #12 THHN on a single #31 toroid) and found that the antenna
didn't like it. It was fine with the same choke wound with #12 enameled
copper.
73, Jim K9YC
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