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Re: [TowerTalk] Impact of high water table levels on antennas

Subject: Re: [TowerTalk] Impact of high water table levels on antennas
From: Bill <bmarx@bellsouth.net>
Date: Mon, 04 Nov 2013 12:34:37 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I am fortunate enough(except during really high tides) to live on a salt water canal. If I dig down about 18 inches I hit water. Yes my verticals with the bases down about 5 ft, hear and radiate well. I easily achieve 1 to 1 without radials( I use them anyway). But it also makes me lazy about getting the yagi back up and working.

So while my location may be the extreme, Ill comment that I doubt fresh water brings the same results.

Bill Marx W2CQ
Ft Lauderdale Florida


On 11/4/2013 12:21 PM, Djordan (personal) wrote:
If that water table is salt water then maybe yes... Fresh water doesn't really 
make that much difference until you get to 160m .

YMMV,
Dave
Wa3gin

Sent from my iPad

Be Prepared Stay Prepared

On Nov 3, 2013, at 2:02 PM, Rudy Bakalov <r_bakalov@yahoo.com> wrote:

Ever since I have put up two inv-Vs, one for 80m and one for 160m, with their 
apexes at roughly 90', I have been puzzled by their exceptional performance. 
Ditto for my vertical on 40m.  I have done tons of comparisons using skimmer 
data and my signal seems to be pretty darn close to the big stations I am using 
as my benchmark. The performance is so good that I have been wondering if I 
should bother with building 4SQs. I have read tons of books on antennas and the 
performance of these two antennas simply does not match what the books describe.

I shared my thoughts with a friend of mine (a WRTC2014 participant) and he 
shared a similar experience with his station. He recently relocated to a new 
place, about 30 miles from his old place, and his antennas at the new place 
perform significantly better than the old location. Same antennas, tower, feed 
line, and FLAT terrain.  His only explanation is that the new place had a very 
high water table that somehow impacted antenna performance.

This is when I realized that I also have a very high water table. Even in the 
driest months of summer, the area around my tower is damp and the grass is very 
green, growing like crazy. This was the obvious common element between his and 
my situations.

I have not seen anything on high water tables in my antenna books.  The soil 
itself is mostly sandy. The impact I believe I am seeing is mostly on the lower 
bands, but I am not sure if this is also the case on the upper bands as at 105' 
my antennas are a bit too high.

Is there any rationale in our thinking? Can high water table explain better 
than expected performance from low band antennas? If so, what is the theory 
behind it and how do I take advantage of it? If not, any other suggestions for 
why the antennas work so well?


Rudy N2WQ
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