Horizontally stacking yagi antennas will give you a deep null. The
horizontal distance determines where that null falls with respect to
the main beam of the pair. Cable tv systems sometimes employ this
method to get rid of an interfering station. You can probably find
some information as to spacing requirements in cable tv handbooks or
antenna manufacturers that supply antennas to them.

Horizontal stacking will give you a much sharper beam width than a
single yagi also.

Not sure of the polarization of the fm stations where you are but in
the US they all transmit both horizontal and vertical.

73
Gary K4FMX

On Sat, 14 Feb 2004 14:21:12 -0000, "Richard"
wrote:

I'm trying to receive some a distant FM stations, but I have locals 0.1Mhz
away that block the desired station out. I could try to use a big gain
directional yagi, but perhaps the solution is to make use of a null.

Anyone know of any antenna system that would produce a real good null in
the FM band? Would that be to try for a cardoid pattern? Or is there
something better than that?


Detail:

Intended Coord.of Interfering Coord.of Angular
station + antenna station + antenna sep. of
Freq. Freq. stations
Mhz Mhz from my
QTH
-------------------------------------------------------
Scarboro' 00w24/ RadioAire 01w34/ 45
96.2 54n16 96.3 53n44 degrees

Bridlington 00w12/ Pulse FM 01w45/ 114
102.4 54n05 102.5 53n48 degrees

Whitby 00w36/ Sunrise Radio 01w45/ 75
103.1 54n29 103.2 53n50 degrees


As you see the seperation between the wanted stations and the interfering
stations range from appx.45 degrees to 114 degrees. Intefering stations are
always anticlockwise to the wanted station, but perhaps that makes no div.

BTW I think the Bridlington transmitter antenna coordinates are 00w12/54n05.
Wonder if anyone can confirm this.

Data obtained from:

http://www.ukwtv.de/fmlist/countries.html

Where Bridlington is on107.4 Mhz, which is now incorrect, because
Bridlington is on 102.4Mhz.

TIA.Rich.