Topband: Ground conductivity, permittivity measurement

[Tom W8JI]

As we all know (should know), those two parameters are esential to evaluate 
the ground under our antennas, especially for verticals.
The ideea to measure the ground concuctivity and permittivity rise after I 
read Rudy's (N6LF) article, "Measurement of soil electrical parameter at 
HF".
I use the "two electrodes" method described on that article which is fine. 
The impedance were mesured with a miniVNA.
Not very precise gear but enough for this proposal. The results amaze me...
I start measurements at the end of May. Since then, the weather was very dry 
with very few rain shower. Very rough drought this year so, very poor soil 
humidity.
In May, conductivity was about 27mS/m and now...only 5mS/m. This is a linear 
function because there were no important precipitations.
>>>>>>

I know we all want to know conductivity. This first because popular when 
Sevik pounded a few rods in the ground and measured on 60 Hz, which became a 
commonly shared but totally useless measurement.

Of course it is much better when we use the actual operating frequency.

It seems to me using two rods in the ground and measuring impedance, in an 
attempt to estimate ground conductivity, might not be very reliable. We are 
not doing anything more than measuring a small area around the rods and 
(especially) rod contact. Rod contact on a freshly pounded rod from soil 
wetting varies greatly, especially with a smaller diameter rod, because the 
soil is not fully settled against the rod.

Have these methods ever been verified with impedance changes in a low 
dipole, or field strength readings, or are they just a proposal?

Richard Fry, you know anything about this? A 5:1 change in soil seems way 
out of line with what I recall from fields at WSPD on 1370 kHz and WOHO on 
1470 kHz.  Were those stations exceptions?

73 Tom