Topband: Modeling the proverbial "vertical on a beach"

[Guy Olinger K2AV]

> One would think if there was a 10-20 db penalty, it would show on skimmers
> and that W2GD would be unbeatable being on the water. I'm sure I'm missing
> something. What is it I am missing?

A contest certainly is not only about transmit signal strength, nor is
the lowest angle propagation always the most productive. There is
always the 27 dB gain between the operator's ears (or lack of it) to
be reckoned with. But usually a station in the contest that shows up
when the shore emphasizes the low angle before full band opening will
usually be there when the band opens with higher angles less
emphasized by the water's edge. A top station inland may not be able
to work him until a half hour later, but if the DX is working the
contest, a top station WILL work him, removing the scoring benefit
from the shore station's propagation advantage.

To win a contest one still has to vacuum out the bands of any little
ole signal that pops up and has to manage 360 degrees of horizon worth
of contact opportunity. Even so, on 160m tests, the consistent
placement of W2GD and K3ZM, particularly K3ZM, in the top few or
outright winning over the years points to SOME persistent advantage,
despite competition around the country with commercial grade stations
and despite inland station staffing with certain clarion absolutely
excellent operators.

Some beach DXpeditons had the advantage of a location where nearly all
their contact opportunity, by the numbers or by the multipliers, was
across the salt water. That's basically not true for anyone in the US,
which reduces any water's edge advantage for a US station. But the
DXpeditions that had 95% of stuff across salt water from the edge
certainly did clean up, even with the 12 dB handicap of 100 watts TX.

As to the signal level contrast driving away from the beach, the
inland soil is commonly very sandy, and particularly when wet is about
as lossy earth as might be found. There is a not-at-all unreasonable
case to be made for the idea that going from water's edge some
hundreds of yards inland is going from sublime "ground
characteristics" over salt water to brutally ugly "ground
characteristics" over damp salt-tainted sand. Once those details are
in, the one or two S-unit difference reports from people driving
around the beach are not so unreasonable.

The other comparison to be made is that antennas over water's edge are
frequently verticals, out of construction necessity. The proper
comparison of a 40m vertical at salt water edge would be to a 1/4 wave
vertical close to ground somewhere out in the W3LPL meadow, not to his
full-sized stacked yagis on a 200' tower.  IMHO a meadow vertical at
W3LPL would be incredibly crappy vs. the same at salt water edge,
easily exceeding two S units in that period where only the lowest
angle signals are peeping through and the band isn't quite yet open.

A warning to ourselves, denigrating and ridiculing ALL anecdota, in
the end, is just as unreasonable as swallowing it all without careful
sorting. It's going to be a tough time introducing progress if
non-owners of FIM-41 commercial MF field strength meters are always
assumed either idiots or bold-faced liars in their reports. A lot of
great food in the world, when raw, is unsavory, repugnant or even
poisonous before being processed into something delicious and
nutritious. We just need to be PROCESSING anecdota.

73, Guy K2AV