NAA17444
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About 1 month ago, I purchased a MFJ-1026. It looked like there
would be some real possibilities to eliminate local noise & QRM. At first
I used my 160 meter vertical as the main antenna and a 160/75 Meter sloper
as the aux (or sense) antenna. I found that with the sloper & the
vertical, I couldn't do much at all with the "1026". I looked at the 1026
users manual & read that both antennas should be of the same polarization
for the unit to operate correctly. I then tried using the sloper as the
main antenna and a all band folded dipole (terminated) as the sense
antenna. With this I was able to very effectively null out local radio
stations allowing me to listen to the more distant stations underneath
them. I was also able to completely null out the noise from my daughters
halogen floor lamp.
Has anyone found the same effects when using the 1026 in regards to
cross polarized antennas? My latest attempt is to use the 160 meter
vertical as the main antenna and a K9AY loop as the sense, or aux antenna.
I cannot use the 1026 to either null or enhance 160 meters signals in this
configuration. What works far better is using 2 receivers tuned to the
same signal and diversity reception. I certainly may be doing something
wrong. Is there anyone here who can give some helpful hints on
using/tuning the 1026? I found that to null stations, both the main &
aux antenna gain settings can't be more then about half way up. I haven't
yet been able to enhance any signals... regardless of what antennas I am
using.
I'm wondering if it would be possible to build some kind of
graphical tuning indicator.... perhaps by using a dual channel scope
looking at the detected outputs from both antennas at once. Something like
this may require construction of 2 receive converters. Perhaps using a
single variable LO driving 2 doubly balanced mixers. I would suppose that
one mixer should be switchable to either the main or aux antenna output
inside the 1026, the other mixer should go to the "phased" output inside
the 1026. The output of the mixers could drive 2 IF chips and then drive
2 diodes for detection. Each diode could then drive one channel of the
dual channel scope.
Does this have any merit at all? Would I see anything useful on
the scope?
73, Dick WA3USG
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