On Fri, 10 Sep 2004 03:50:44 GMT, A-Tech hath writ:
Hi,

I am a newbie here and have just dropped in to ask a single technical
question.

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.

I think, as Roy suggested, that your best attack will be to aim
the antenna to provide the deepest null to the "... off-axis
stronger signal at 106.9MHz". Peaking the desired signal is
only a secondary goal here.

Don't spend a lot of Big Bucks trying to solve this problem.
Marvin's Law (Murphy's brother) says that once you _have_ put
considerable money, effort, and time into this, the station's
(new) owner will change the format to Country or Jesus.
(Now, How's *that* for provoking thread drift?)

gl es 73
Jonesy
--
| Marvin L Jones | jonz | W3DHJ | linux
| Gunnison, Colorado | @ | Jonesy | OS/2 __
| 7,703' -- 2,345m | config.com | DM68mn SK