{original msg at end}
Firstly, let me thank you one and all for your responses!!

Also, I did not clearly define the antenna which is a
multi-element yagi of Winegard design - a "standard"
consumer product - and roof mounted.

In addition, I have MapQuested
the two transmitters and find that the interfering
radiation comes from behind, about 25degrees
off axis. This signal originates about 30miles behind
me and the desired signal is about 55miles in front.

Richard Clark took me along the method that I had
tried - and that I have had no success with.

Dale W4OP points out that this type filter,
at these frequencies, have almost no effect - boo!

Roy Lewallen, W7EL, concurred with Dale and suggested
a "phased array" design. Unfortunately, this is beyond
my capabilities. Roy and Walt, W2DU, both agreed that
using "null tuning" might help. Roy also suggested a "choke"
for the feedline to reduce feedline pickup. - But it seems to me
that 95% shielded 75ohm coax should not be a
contributing factor.

Bob suggested that I call the offending station - I did that
but I have to wait until Monday to speak with their
engineer - boo.

Crazy George alluded to an article about constructing
a "stacked yagi" - interesting and within reasonable
economics - but no details or source for details. Ah well.
He also brought back into my memory EagleFilters
which I have used in a cable television distribution
setting. I'm looking them up on the Internet now.

"jqo" suggested shielding from the bad signal, a strategy
I have successfully used in C-Band-satellite-receiving-antenna
placements but....on my rooftop? Also, he suggested a tuner
with better selectivity. I agree and am on eBay looking for
a better unit than the Cadet AM/FM Radio card that is
installed in my PC and connected to the outdoor antenna.

BTW, "jqo", Q, in a filter, means "quality" but is really a
figure of merit that refers to width of the 3db down points
(in frequency) and the total energy removed. High Q filters
have narrow -3db points and suck out LOTS of energy.

Jonesy suggests that if I just wait, like the weather, the station
will change format and I'll no longer care to solve this!!

Thanks all - any additional comments are most welcome.

....Bryce


"A-Tech" wrote in message
news
Living as I do in a suburban area, I use an FM antenna to draw the
stations
located in a certain vector from me. A station of interest is located at
107.1MHz but
is interfered with by an off-axis stronger signal at 106.9MHz

The FM antenna has a "standard" 300ohm screw connection for the lead-in
(to
which I connect a 300/75 xfmr and use coax down).

I would appreciate anyone's help in designing and implementing a notch
filter that would suck out a major part of the interfering energy.
It seemed to me that a reasonable attempt would be to use a piece of
300ohm
flat-lead and short it at an appropriate distance from the screw-terminals
of the antenna. None
of my attempts have yielded any observable improvements. It may be that
the filter must be
"deeper" (higher Q?) than what my attempts provide.

A-Tech wrote:
. . .
Roy Lewallen, W7EL, concurred with Dale and suggested
a "phased array" design. Unfortunately, this is beyond
my capabilities. Roy and Walt, W2DU, both agreed that
using "null tuning" might help. Roy also suggested a "choke"
for the feedline to reduce feedline pickup. - But it seems to me
that 95% shielded 75ohm coax should not be a
contributing factor.
. . .

With the added knowledge of your antenna and your technical
capabilities, the approach I'd encourage you to try is to simply turn
your antenna while listening. It might not take much turning to get the
interfering signal into a null, leaving the desired signal close enough
to the peak of the front directional lobe to be strong enough.

The problem with feedline pickup has nothing to do with the shielding,
it's caused by current on the outside of the shield. But it's not likely
to be a concern with your commercial antenna and coax because of the way
these antennas are typically fed.

Roy Lewallen, W7EL