Happy New Year to all on the reflector!
The Stew Perry 2003 offered little in the way of good DX conditions, an
enormous amount of S9+ QRN and a startling insight into antenna performance
in VK6.
The geomagnetic latitude/longitude of south-western Western Australia
should offer some advantage to a predominantly vertically polarised antenna
over a horizontal one, but results at VK6VZ over seven years of 160m
operation have shown this not to be the case in practice from Glen Forrest
(some 50km from the coast).
After much experimentation with both horizontal and vertical antennas from
GF, my conclusion was that the far-field losses with vertical antennas,
owing to the ground being predominantly rock/gravel, were just too high for
a vertical antenna to work as well as a horizontal one. Whatever I did -
including burying an eighth wavelength radius ground screen - my
inverted-Ls/Marconi Ts were inferior as a transmit antenna 97 per cent of
the time, equal for about 2.9 per cent of the time and better about 0.01
per cent.
However, the Cape Leeuwin site used for operations during the Stew Perry is
on a 1km-long peninsula, surrounded on three sides by seawater. If a
vertical antenna was going to work 'gangbusters' from this part of the
world, it was going to work here and, as a result, a quarter-wave wire
vertical was erected from the lighthouse balcony to the ground, fed against
a tuned counterpoise via a choke balun, in addition to the usual inverted
vee dipole at 39 metres above ground.
Although the performance of the two antennas were similar on receive, the
vertical offered up to a 2 'S' point advantage on transmit. With the poor
conditions on offer and my own prejudice against using verticals from this
part of the world, this fact was not realised until a few minutes before
sunrise during the SP...
Next year, vertical antennas - maybe two phased wires - will be used
exclusively for transmit from VK6VZ/6.
Owing to the poor conditions, QRN and the low power used, only 7 and a half
QSOs were made. The 7 QSOs were made up of two VK6, one VK3, GM3POI,
RW4PL, RA1ACJ and A61AR. About 20 Europeans were heard and called without
success.
As for North America, the S9+ QRN after sunset, owing to the hot humid
weather here, made the band all but useless. Half a QSO was managed with a
W7, but that was all.
Vy 73
Steve, VK6VZ
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