Here's the setup at my station.
The antenna is a center fed multiband antenna (centerfed zepp?), 130
feet long fed in the center with 80 feet of 450 open wire feedline,
matched with a Johnson KW matchbox. Been using this antenna for a
long time and works good. The radios are an FT-1000 and TS950SDX,
The problem is a radio station has setup operation about 2 miles from
me and I am getting a third harmonic (s9+10) at 3.990 with a mix at
3.790 (S9+), the mix is between a 50 kw station (several miles away)
and the 10 kw station 2 miles from me. they are on 1130 kc and 1330
kc. Both radios receive it equally well.
The question is, if I were to change my antenna to a simple dipole
with a SPC type match box, is it possible that combination would help
my situation? I dont think it will but I thought I would ask anyway.
I've talked to the station managment, they are sympathetic but not
too much help, they say it has to do with ground conditions maybe the
phone lines which I think may be true to some extent. I have driven
around with the mobile and the mix signal varies in strength around
the area.
I know there isent much I can do about the third harmonic at 3.990
but what about that mix signal at 3.790?
Any ideas would be helpful as this has put me off the air at the high
and low end of the 75 meter phone band.
Dale J.
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