On Wed, 24 Jun 2009 20:41:39 +1200, Greg - ZL3IX wrote:
>Several guys have told me that they have not managed to get this idea of
>running the coax between the arms of the antenna, to work. I have also
>realised that I would need two relays, or a 4PDT relay, as I would need
>to isolate the grounds as well.
To take the coax out of the equation, you simply need to apply monster
multi-turn chokes to the coax. See the Cookbook in my tutorial for winding
details. In this application, I would try to achieve 10K impedance at
frequencies of interest. This may require multiple chokes in series. No
problem -- theyre cheap. :) Just dont forget to include the length of
coax wound on the cores when figuring the length of the feedlines for
phasing purposes. The cores do NOT change anything -- the coax is simply
additive.
http://audiosystemsgroup.com/RFI-Ham.pdf
73,
Jim K9YC
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