On Tue, 25 Dec 2007 13:40:44 -0600, FireBrick wrote:
>I built the 12 turns of rg58 through a FT240-61 core as suggested on the
>K9AY site
>Between the U and balun and my viking tuner, I have a good match.
FWIW, 12 turns of coax through an FT240-61 core is a LOUSY choke on 160 (in
fact, it's a lousy choke on most bands). A MUCH better choke for 160 would
use the #31 cores we bought in a group purchase several years ago. It won't
affect the MATCH, but it will do a far better job of decoupling the antenna
from the transmission line, which can make the antenna quieter on RX.
See the section on coax chokes in http://audiosystemsgroup.com/RFI-Ham.pdf
and http://audiosystemsgroup.com/CoaxChokes.pdf
73,
Jim Brown K9YC
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