> > Bottom line: there may be reasons other than direction of signal
arrival that allow a signal to be better copy on one receiving
> >antenna rather than another.
> >
> This is another reason that you may not really know which direction a
> signal is coming from, even to the resolution you might get based on the
> HPBW of your beverages.
That certainly is a reason why wide pattern antennas, like a loop or an
antenna with a wide forward lobe and narrow back null, cannot determine path
direction when S/N ratios are low!! It doesn't apply very often to antennas
with good directivity.
The only possible way to improve S/N ratio is to null the offending noise
more than desired signals. With a reasonably narrow main lobes and 15-20dB
of spurious response suppression, you aren't very likely to find cases where
picking the "wrong direction" improves S/N.
(I do sometimes pick the weaker path if the signal has two distinct paths
usable at the same time and the weaker signal path is significantly
quieter.)
All that aside, there is plenty of time to look at signals without QRN. From
my experience the reports people give of the skewed path generally NOT
aligning with grayline are correct. I've never seen a consistent skew
alignment with grayline.
Longer distances and high absorption paths are much more likely to skew.
73 Tom
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