Jeff,
Thanks for re-posting Kevin's log. I have looked through it and the main
impression I come away with is that the two-mode ducting was in effect in
the ionosphere from 1014Z when he worked VE1ZZ to about 1100Z, ending by
the time he worked WV3B. And by the looks of it, the greatest problems
with the multi-pathing was for stations close to their sunrise.
Now Kevin revives the long-path idea and let me shoot that in the head,
once and for all. All you have to do is look at all the sunlight on that
path with your mapping program and you will know there is just NO WAY
that a 160 meter signal could survive. So let's just leave that idea
lie where it is. It will get us nowhere.
Now I am not an "antenna person" so I will defer to the experts on that
but I do know that beam or phased antennas have back lobes and they
can be non-trivial in their effects. Who hasn't worked some DX off the
back of his/her beam? So when you say you think it is long-path to the
SE, not short-path to the NW, I immediately think of a back lobe. And
when you say the signal went UP in strength, I think it must be a BIG
back lobe. And when you say "sunrise", I think of high angles, making
that back lobe a high one.
Now with one last item, I will relax and wait for the NEC experts to
weigh in; if you RECEIVE well on a lobe, front or back, you will TRANSMIT
well on it too. So I am still not surprised by Kevin's report about your
signal; it is consistent with the back lobe idea. But the NEC guys can
work this over.
I really don't think much of side-scatter by the ionosphere as a possible
explanation but Rob, K2WI, suggested some sort of ground reflection. Now
reflection off of ground is much more efficient so signal-wise, that may
be a possibility. It would then depend on the slope and orientation of
the hillside, mountain or whatever. I am a Westerner, through and
through, and I really don't know what your geology is like. The only
thing I can say at this point is that for ground reflections to be the
answer to your problem, it would be some sort of mountain range or
whatever to the southwest of you. Any reaction to that?
OK, I am poised and ready to see what other reactions that set of QSOs
brings forth. "Gentlemen, man your keyboards!"
73,
Bob, NM7M
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