Rob's comments would suggest that at the bottom of the lake, where the water
is in contact with the earth, the conductivity would be good, just like wet
earth with an insulator above it - so while the WATER is not doing the
radials' job, the bottom of the lake IS.
-Rex-
K1HI
Rex Lint
Merrimack, NH
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Roger Parsons
Sent: Friday, November 13, 2009 5:10 PM
To: towertalk@contesting.com
Subject: [TowerTalk] antennas in fresh water
Thanks for your comments Rob - I generally agree with your observations.
However, my particular cases were (1) An AV3 10-15-20m vertical which works
much better at ground level close to the lake than it did 40' from the lake
with the base at 20' with tuned radials and (2) A 40m vertical which works
dramatically better about 10' from the lake than it did sitting in a swampy
area 300' from the lake.
On 160m I use a 95' top loaded vertical about 400' from the lake with lots
of long ground radials - it seems to work quite nicely. I recently put up a
60' inverted L close to the lake (mostly because I could :-) - I am looking
forward to comparing the two. On receive there seems to be little difference
and I suspect that will be the case on transmit as well when I get round to
making the switch box.
I still think that the clear take-off over the lake must help - possibly
because it is not obstructed but also possibly because it is likely to be a
better reflector of grazing signals.
73 Roger
VE3ZI
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