The "Team Vertical" prime movers, K2KW and N6BT, have answered this
question. A good rule of thumb is the antennas should be no more than
a quarter wavelength from the salt water. More information is
contained on K2KW's site, http://www.k2kw.com/verticals/learning.html
.
I had a first hand demonstration of this on our 2003 C5Z operation
from a north-facing beach in Gambia. Two 20-meter verticals were set
up, one on the water's edge and one 150 back from the edge. The one
away from the water had 150 feet less feedline loss. The difference in
signal strength from USA stations was over 2 S-units in favor of the
beach antenna. I became a believer.
Our 2008 HQ3Z operation from a north-facing beach in Honduras
presented an interesting opportunity to compare high horizontal beams
against beach-mounted verticals on the high bands. On 20-meters, a
200-feet high, 3-element, portable, Force-12 beam outperformed a
2-element beach-mounted vertical array in our comparisons to the
extent that we did not use the verticals. The same applied to 15 and
10 meters. With the capacity for both beach verticals and high beams,
the Honduras location seemed ideal. However, it was two time zones
west of the eastern Caribbean stations who clobbered us into Europe,
and also had pretty bad power-line noise which we were unsuccessful in
getting fixed.
73,
Dick Norton, N6AA
On Fri, May 21, 2010 at 6:13 PM, Lew Sayre <w7ew@arrl.net> wrote:
> Yo,
> OK, so a salt water take off is good for Tx and Rx. What about
> an archipelago or salt water bay or salty straight where you'd have 20-30
> miles of sea water before running into land? You think that would be almost
> as good as open sea water or maybe just a bit better than good terra firma?
> Anecdotes- studies-experiences? We had salt water near us, surrounded by
> a smallish land mass engulfed by the South Indian Ocean at FT5XO and the
> verticals seemed to play pretty well.
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