On 11/7/2020 11:04 AM, Tom Osborne Sr. wrote:
One thing I have wondered. I saw sometime back, that taping the coil of
coax to the boom of the antenna hurts the function of the coil. Is it
better to just let the coil hang down, maybe from a line or something,
instead of taping it to the boom? 73
Hi Tom,
First, a coil of coax with no ferrite core is a lousy choke. Second,
yes, capacitive coupling between the coax and the boom on both sides of
the choke de-tunes and defeats the choke. There's a photo in
http://k9yc.com/ChokesVHF.pdf showing what I asked Hector, XE2K, to do
when he rigged my new 6M antenna. There are two half-sections of PVC
conduit between the chokes and the boom. The coax is a very low loss
PTFE version deigned for use in plenums. He developed a different method
to rig the choke on my SteppIR.
73, Jim K9YC
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