Topband: Re: [TowerTalk] Vertical in salt water- questions?

[W0AH@aol.com]

<< 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 
tide.
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 
the dock. 
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 
radials.  
Doug  W0AH


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