Topband: locals

[Rick Karlquist]

W7lr at aol.com wrote:
> For the contest a local high power multi station moved in a few blocks
> away.
.
>
> Is there any in-band filters that might help, or any other ideas?  I
> would
> like a remote antenna but it doesn't seem practical here.  I could  visit

The trouble with a receive filter is that the transmitter may
have broadband noise, and it won't help that.

I run SO2R in 160 meter contests by using a loop antenna
for the second receiver.  The loop antenna is about 900 ft away
from my transmit vertical.  I can get 60 or 70 dB of nulling by
carefully orienting the loop.  I am able to get excellent receive
sensitivity to within 5 kHz of my transmit frequency.  I am planning
to improve the null even more by summing in a "sense" vertical with
a variable amplitude and phase combiner.  You can get details on
my loop antenna at:

http://www.n6rk.com/loopantennas/pacificon.pdf

You might be able to null the neighboring station in the same
manner as I null my own transmitter.

Rick N6RK