[amsat-bb] Re: DFing Terrestrial QRM
jshorney at inebraska.com
Fri Sep 21 17:46:50 PDT 2007
On Fri, 21 Sep 2007 18:10:05 -0400, Robert Bruninga wrote:
>>>... Now it is time to get out of the car and walk.
>>> Holding HT on your chest. You have a NULL out
>>> your back. Use it to get walking directions and
>>> by now you are within yards of the source.
>> ... this has never really worked for me, much to my
>> surprise. Dunno why.
>When walking with the HT, I periodically stop and with the HT
>held tightly to chest, do a perroiette (I have no clue how to
>spell a french dancing maneuver)... Lets call it a spin in
>place. My ear hears the subtle peaks in the back ground noise.
>The direction of my back on those subtle and narrow noise level
>peaks is generally the direction to go next.
There's also another way. A garden-variety rubber duck will often have a
fairly sharp null off the end of the antenna. Hold the HT horizontally in
the clear away from your body and spin it around. Where the signal shows the
sharpest null, your antenna will be pointing at the source. You can check
for this behavior with a known signal source before you try DFing.
Ham Radio NU0C
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