Actually James hit on an important point here: feedline length.
Actually it has nothing to do with impedance matching but everything to do
with the behavior of common mode current on the feedline.
Unlike the transmitted RF current which is the same for the entirelength of
the feedline, common mode current is not the same at all places along the
feedline. It varies constantly.
It is worst a half wavelength away from the feedpoint and minimum a quarter
wavelength away from the feedpoint.
You must consider the vf of the feedline (but not its transmission line vf,
rather the vf of the individual wires - which is probably about .97 our
.98).
G3TXQ reports measured data on this on his web site at the bottom of his
page on RF chokes:
http://www.karinya.net/g3txq/chokes/
You didn't specify which band(s) the problem is on.
A quick try would be to insert 1/8 wavelength of additional feedline between
the existing feedline and the JV Matchbox.
Of course it you are on 80m, this is not going to be an option.
I still suggest the dual RF choke as per my previous email.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of TTMaven
Have you tried different lengths of feed line - window line and coax,
respectively? I won't recite all the reasons here, but you know how various
lengths of feed line matter to impedance matching, etc.
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