In a message dated 98-11-19 19:09:48 EST, k2fr@juno.com writes:
> At the old qth I had a TH7 on top and a homemade 80/40 sloper about 3 ft.
> below it. Worked very well. Now the new sloper is about 3 ft below the
> C3
> and it only resonates on 160. There are NO guy wires or nearby metal
> object.
> The tower is grounded by a rod about 10 in the earth. The swr on 40 and
> 80
> is flat across the band AND I have a serious problem getting a match with
> a Murch tuner. Basically it will not match any better than w/o the tuner.
Since the only metal in the near field is the sloper and the C3, it's
probably interaction between them. Lower the sloper and see what happens to
the C3 SWR. Power up the C3 and rotate it while watching the SWR with the
sloper in place.
>
> Local guys are stumped. Ideas I have are bad coax connector at antenna.
> Or, with no balun or coax coil the antenna may be coupling to the tower.
> The
> coax comes down the tower to a RCS-8V remote switch.
You need to use a process of elimination. Send somebody up the tower
to measure the antennas at their feedpoints with an antenna analyzer and work
your way back to the shack from there. Sounds like either antenna interaction
or something in the cables.
Cheers, Steve K7LXC
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