On 2012-10-08, at 12:12 PM, Jim Brown wrote:
> While we're talking about propagation, I'd like to understand what form I'm
> experiencing during the beginning hours of 160M contests. They start at 2 pm
> out here on the left coast, which is at least 2 1/2 hours before sunset,
> depending on which contest. Within the first year after moving here, I've had
> a dipole at 120 ft and a Tee vertical with a lot of radials. I find that I
> can repeatably work the better stations at distances of 800 miles or so on
> the vertical, but don't get even a QRZ? from the dipole (I'm 70 miles S of
> San Francisco, so that includes Seattle, Phoenix, Salt Lake City, and parts
> of WY, MT, NM, and CO.
>
> Now, 120 ft is only a quarter wave on 160, so that's still a "low dipole,"
> and the radiation at low angles isn't as much as from the vertical, but the
> difference seems greater than just angle. So I'm wondering what form of
> propagation this is at this time of day? Could it be ordinary ground wave?
>
> Also by 3 pm I can always hear the stronger stations from W9 and VE3, but can
> almost never work them. I understand the differences in the noise levels
> between my daytime and their darkness, and there's also the fact that they're
> all listening with NE RX antennas. But again the question is, what form of
> propagation is this? W9 and VE3 are 2,000 miles from me, and the path is in
> daylight!
>
Hi Jim,
One of my personal pleasures in working the 160-meter contests is the fact that
the band is surprisingly open at times that are unexpected...
It's fun to work into the mid-West, and as far south as Georgia, practically at
high noon!
I have no idea what propagation mode(s) comes into play on such occasions, but
it is definitely there, and quite real. Signals are NOT especially strong, but
they are readable...
One of the many joys & lures of Topband, to be sure...but a pity that such
activity seems to make its presence known only during contest situations!
~73~ de Eddy VE3CUI - VE3XZ
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