On Sat, 16 Jun 2007 22:50:05 -0700, Dave Hachadorian wrote:
>If f/b is degraded, try lengthening or shortening the dipole's
>feedline to detune it
A much better way is to add one or two good common mode chokes (some
turns around some ferrite cores) to the feedline. See the tutorial on my
website.
http://audiosystemsgroup.com/RFI-Ham.pdf
Study the section in the tutorial first about baluns and chokes, then see
the section on using chokes as "egg insulators" in the feedline to
prevent them from interacting with other antennas.
For details of how to wind the chokes, see the following internal
communications I shared with other guys who were doing their own choke
research. I haven't had time to finish the measurements (I've been on the
road a lot) and revise the tutorial to reflect the new data.
http://audiosystemsgroup.com/ChokeMeasurementsK9YC-K6TD042207.pdf
http://audiosystemsgroup.com/ScalarChokeMeasurements1.pdf
73,
Jim Brown K9YC
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