Mike,
It is not that they are near an ocean. It is if the conductivity of the
salt water is near enough under the beverage element such that the salt
water (or salted earth ie. salt marsh) is acting as the other conductor of
the "twin lead" transmission line (the Bev wire is one conductor in the
transmission line and the earth is the other conductor).
If the Beverage is far enough above such conductive earth so that the "earth
conductor" is a bed of sand, coral, or non-salty earth, it will perform in
the classic fashion.
This was proved at XZ0A in 2000. The bevy of Beverages were constructed
over the top of the island through jungle foilage for the most part. There
was considerable earth and probably rock below the Beverages down to the sea
level. The antennas performed excellently.
I also constructed a mirror image of the Bev oriented to JA, but installed
it along the shore line with nothing but shore rock at low tide and sea
water at high tide. This antenna was an absolute dummy load whereas its
twin, located a couple of hundred feet distant, was performing normally.
Three years ago on Ducie at VP6DX the Beverages were all constructed over
the island with the ends terminating within ~ 30 feet of the open ocean or
lagoon. The maximum elevation of Ducie is about 15 feet AMSL. The surface
composition of the atoll is a deep bed of coral fragments and dead shell
pieces.
As evidenced by the accomplishments of the low band operators during the
peak of the austral summer, the Beverages worked extremely well.
This is the Beverage operational theory as I understand it, and have proven
conclusively to myself to be true. Your mileage may vary.
73 de Milt, N5IA
-----Original Message-----
From: Mike Fatchett W0MU
Sent: Thursday, April 21, 2011 8:36 AM
To: topband@contesting.com
Subject: Topband: Beverages near the ocean
I was reading ON4UN's Low Band DXing Book and ran across a comment he
made about beverages not working near the ocean and the Heard Is folks
could never get one working. I know we used one from V47 and it worked
great. It was located probably no more than 300 ft from the water.
This is the first time I have read or heard of this phenomenon. Have
others had issues with beverages near the ocean?
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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