Pete W2PM wrote:
>>>>>I often find that if I can get a modest null, then I can find a
>>much deeper and profound one with extra work either in futzing with
the
> ........ etc.
>>>Bob AA6VB replies:
>>I have a two position antenna switch and switch between the K9AY loop
>>and a wire lying on the roof. I plan to change to a multiple position
>>switch and add several more sense antennas so I can see which one give
>>the best results on any given day.
W2PM Replies:
BTW when I find a profound null, and it's great as it takes away nearly
ALL of the crud, it's at a setting where the main antenna level is very
low and the noise even lower. So the Null is found with the level
controls less than 1/4 up, sometimes less. I rarely find a profound
null at higher levels on 160, but on 30 meters and higher the levels
are higher. While this brings signal very low, if readable at all on
the S meter, they are perfectly readable. Even with lots of other QRN,
the audio DSP works much better without the raucous local electrical
noise removed by the nulling. This technique still often requires the
noise to be amplified going into the 1025 and then reduced with the
Noise antenna level control. At least in my situation which is pretty
bad wiht 20DB over S9 line crud at times.
Another excellent mod is reversing the noise antenna and main antenna.
(SEE W8JI mods on his site) You don't have to do the mods wiht the
relays to test it - simply plug your main antenna into the aux noise
antenna and vice versa (BUT DONT TRANSMIT!!!) .. the nulling range is
more available and less critical. 73
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160 meters is a serious band, it should be treated with respect. - TF4M
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M
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