[TowerTalk] antennas in water
W4EF at dellroy.com
Wed Mar 18 10:17:07 PDT 2009
CRAIG CLARK wrote:
>My 160 vertical is located in a fresh water swamp. The key to it's success
>has been the thousands of feet of radial wire I have laid down.....not on
>the water. I located it there as it was away from the house and out of sight
>from the wife and the road, not for any perceived benefit from location.
>Fresh water is not a good conductor.
I don't think anyone is disputing that, Craig, but neither is dry rocky
soil a good conductor (trust me, I have first hand experience with lousy
soil). Seawater is clearly superior to either of these two by several
orders of magnitude (about 3 in the case of average soil). The relavent
questions are whether rain soaked soil or fresh water lakes are
significantly better than average or poor soil. I suspect the answer is,
yes, but I don't have hard data to back that up.
I think I remember reading that W8JI had some data for a fresh water
proximate BC sight that suggested the lake was somewhere between 15 and
30 mS/m, but I may be misremembering. I would be real happy with 15 to
30 mS/m compared to what I have now. I recall that the KS8S/AD8P contest
station in Deshler Ohio (Northwest region of state) was right in the
middle of a 15mS/m zone on the FCC conductivity map. From what I
understand you could dig down a few feet into Dean's yard and hit water.
It seemed like you could shunt feed a piece of spaghetti there and do
well on 160.
BTW, even if the muck in your fresh water marsh has improved
conductivity over dry soil, I wouldn't expect that to obviate the need
for a good radial system. Copper is still a many many orders of
magnitude better conductor than even saltwater. I would expect the main
benefit of the mucky soil to be a positive impact on the psuedo Brewster
73, Mike W4EF.............
>With all due respect to other posters,
>most of the comments have been anecdotal in nature and do not reflect any
>scientific measurements of performance.
>I have done any number of searches from Terman to Laport and Google and can
>find nothing that touts locating an antenna in fresh water to enhance
>Craig Clark K1QX
>PO Box 209
>Rindge NH 03461
>603 899 6957
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