Re: LF: EARTH RESISTANCE

["Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>]

At 18:27 16/12/2002 +0000, you wrote:
>   
> Hi all
> Dick has indicated that Earth Resistance gets
> higher when the ground is wet. That seems strange and contrary to
> accepted theory. The ideal ground plane for a vertical is on a wet plain
> or preferably positioned in the middle of a lake or in the middle of the
> Ocean. Have I missed something and read his observation
> incorrectly.
> de Mal/G3KEV
>  

In many cases wet soil will conduct better than dry soil, but not
alway.
As the water in the soil dissolves the salts conductivitity will
increase, bit once (almost) everything is dissolved more water will make
the solution "thinner" and thus decrease conductivity. 
Could it be that in places with a "natural" low soil loss (so
most salt already dissolved) rain will increase the loss while with poor
soil it will decrease ?
By the way, an antenna in the middle of a sweet water lake might not work
very well as sweet water is a rather poor conductor, in contradiction to
salt water.
Another thing I observed : during rainfall the loss resistance increases
and only starts sinking a few hours (or even days) after the rain stops
:
day 1 (dry) : 115 Ohm
day 2-3 (heavy rain) : gradual increase to 130 Ohm
day 4-5 (dry) : gradual decrease to 95 Ohm
day 6-10 (dry) : gradual increase to 115 Ohm
I believe that the first increase is caused by the wet greenery, after
the greenery dries up (but soil is still wet) the decrease starts and
after the soil dries up I am back to start.

73, Rik  ON7YD