----- Original Message -----
From: "RICHARD BOYD" <ke3q@msn.com>
To: "Towertalk" <towertalk@contesting.com>; "Michael Harris"
<mike.harris@horizon.co.fk>
Sent: Friday, December 03, 2004 7:38 PM
>
> On verticals on the beach (or not)... my recollection of the Force 12
"Team
> Vertical" guys, what they said in a Dayton Antenna Forum presentation
(about
> one of their 6Y, Jamaica, operations), is that they found signals peaked
at
> 1/4 wavelength back from the water's edge, apparently not at the water's
> edge or out on a dock or something.
>
> Also, others have told me, empirically (seat of the pants) that they
thought
> the advantageous salt water effects on vertically-polarized antennas might
> be noticed up to a mile inland from the water. I assume they diminish the
> farther away you get after that first 1/4 wavelength.
>
> 73 - Rich, KE3Q
The beneficial effects from the high conductivity aren't so much from the
good ground plane close to the antenna, but because a bit farther out, it
supports a low angle reflection. Consider, for example, a takeoff angle of
10 degrees. If your antenna is, say, 20 feet off the ground, the "ground"
location where the reflection hits (and will reflect at 10 degrees) is 113
feet away. For 5 degrees, 230 ft, and so forth. If you've got an antenna
that's up a few hundred feet (say on a hill or bluff overlooking the sea),
then you can be quite a ways inland.
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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