K9YC wrote:
>N6BT gave a very interesting talk at Pacificon last fall (2015)) that
>addressed something like this. He set up verticals (memory fails, I
>think it was 20M) at three locations on a plateau with drop-offs on all
>sides. At the edge of the plateau facing SA, he worked SA and no JA. At
>the edge facing JA, he worked JA and no SA. In the center of the
>plateau, he worked neither. He used a drone to measure the vertical
>pattern and found the field strength increasing a bit below zero
degrees
>elevation.
Here's another data point, from 40m. My 4-square is at the end of a
small ridge which slopes away in all directions from West through to
North. With a main lobe at 290deg, this antenna was ideally situated for
the HAARP moonbounce tests in January 2008.
The first hour of the tests was on 6.7MHz and coincided with moonset
here in NW Europe, with the moon passing pretty much through the main
lobe of the 4-square. To my great surprise, I could copy *everything*
from the moment the test began. The 2-second pulses of the 'uplink'
signal were presumably arriving by ionoscatter, then the delayed moon
echos were clearly audible in the 3-second gaps.
Moon elevation angles during the test ranged from 7deg down to my local
moonset at <1deg, with good copy of the echos throughout. Even with the
rocky terrain that we have here, the sloping foreground ensures that the
4-square remains effective down to very low elevation angles.
73 from Ian GM3SEK
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