evans wrote:
: Is there a directional antenna that can be used with a handheld
: scanner ? I'm trying to track down the origin of a signal in my
: neighborhood.

: Can one be made easily ?

You didn't say what freq you want to search on.

BUT there are a number of tricks you can use with what you already have.
FIRST, I assume that you can hear the signal with the stnadard rubber
duck.

The first 'trick' is called "body fade". Hold the radio close to your
chest and listen to the interference. Now, slowly turn around in a 360 deg
circle as you stand in the same spot. At some point in the circle the
signal should either fade, or cut out altogether. When this happens keep
turning and see if it comes up. If so, stop and turn back and try to find
the deepest "null". STOP. The interference is directly behind you.

If you have a map of the area now would be a good time to draw a line on
the map in that direction. But if the source is fairly close it's not
necessary.

Do this a number of times in different locations to see if all the "lines"
point in the same general direction .. if so move toward that location and
repeat the procedure.

If you get so close that you don't hear any "null" when doing this, try
removing the antenna from the radio. If you are so close to the signal
that you can remove the antenna and still hear it, you can keep doing the
procedure without the antenna.

Another 'trick' is useful when getting close ... instead of listening to
the primary freq. (interference is strongest on xxx.xxxx mHz) listen to a
multiple of that freq (harmonic) say 2 times xxx.xxxx or even 3 times
xxx.xxxx if your radio goes up that high. This may not work if the
offending interference is broadband and you can't pin down the freq.

Good luck

Richard in Boston, MA, USA
N1JDU