Exactly right, Scott. The farther west we are, the greater the length of
the part of our path to EU that's through the auroral oval, which adds
both attenuation and sometimes flutter. From near San Francisco, I do
FAR better to AF than to EU. Stations in NM, AZ, and SoCal have a
marginally better path than mine.
And, as others have noted, paths with reflections from water can be
stronger than those over land.
And any meaningful analysis must be of large samples, to average out the
randomness of propagation. I've used the RBN when there's little or no
band activity to troubleshoot issues with my TX antennas. I did the
study in 10-12 nights spread over several weeks, each night transmitting
TEST K9YC into one antenna and TEST W6BX into the other, six times in
sequence for each call, alternating between the two, then pausing for
5-10 minutes, and repeating. I loaded reports from each reporting
station into a spreadsheet, then tabulated and averaged the results for
each, and sorting those averages by azimuth. All three antennas have
some directivity by virtue of interaction with each other and my towers;
I did separate A/B tests like this for these combinations. The results
clearly confirmed results during contests -- two of those antennas are
about 7 dB down from the third.
The problem is either the connections in the radial system for the
tower, which acts as a passive reflector for the two antennas, or
absorption by the dense redwoods that surround them. Can't do anything
about the trees, but I'm working on the radial system.
73, Jim K9YC
On 11/11/2021 11:04 AM, K9MA wrote:
The results of one contest really don't tell you anything. Propagation
is just too variable.
One of the biggest factors in DX contests is how close the path goes to
the magnetic pole. If you play around with Google Maps, which will plot
circle routes, you will see, for example, how that path between EU an NA
varies dramatically as you move the endpoints east-west, at the same
latitude. A station in NA 200 miles east of another usually has a huge
advantage on that path. I hear that all the time: a station 200 miles
east of me working Europeans I can't hear. For non-polar paths, I don't
think there is often a big difference due to longitude.
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