Topband: Re: [TowerTalk] Vertical in salt water- questions?
Tue, 21 Nov 2000 13:25:08 EST
<< Please advise what experiences you have had with "verticals in saltwater"!
Thank You- NO4S: FROM TOWERTALK
I recently used a twenty year old, Hygain 18AVQ 10-80M trap vertical over
salt water, the Carribean sea, north of Cancun where I operated XE3/W0AH in
the CQWW Phone. The reputation of a vertical over salt water is for real.
Running an IC-706 barefoot and almost 200' of coax to the vertical, I made
2660 contacts with some very strong signals from Europe and Asia, indicating
a low angle of radiation.
The antenna was monted about 25' out on a 70' dock, about 3 feet above high
I had mistakenly thought that dropping a ground into the salt water would be
as good as radials. Tom, W8JI, and others advised me that while salt water
has several thousand times the conductivity of average earth, it is still
only about one thousanth as conductve as copper wire and therefore radials
are absolutely essential.
I placed four 20M 1/4 wave, two 40M 1/4 wave, and two 75M 1/4 wave radials on
I had an MFJ antenna analyzer and tried to use resonnate 1/4 wl radials, but
gave up as each additional radial changed the resonnance of the ones already
laid. Remember these radials were on a dock only about 8' wide, so were laid
close to each other. I did not have 10M and 15m radials because I had
expected to use a homebrew 10M/15M 2 el quad, but a freak storm destroyed it,
so I used the vertical on 10M and 15m with FB results.
I also made a few contacts (as far as Canada) on 160M with a 1/4 wl resonnant
piece of wire slopping up at a 30 degree angle from the base of the 18AVQ to
a palm tree, maximum heigth 25' and average heigth only 15' above ground.
I'm sure it would have worked better with a couple of 160M radials which
would have had to be on the beach since the dock wasn't long enough. Next
trip down there I plan to use an improved inv. L on 160M with two 160M
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