Topband: ground characteristics

[Tom W8JI]

Hi I have no idea if it is a fact but on page 9-18 in ON4UNs book it is 
stated without any further explanation -

"It is impossible to make a direct measurement of ground 
characteristics".>>>

I know we get a lot of vocal authoritative definite answers on many esoteric 
things, including this, but I think we should all be very careful to use 
some common sense and caution. Everyone took off with Sevik's method at 60 
Hz, and it had very little correlation to what actually happens at higher 
frequencies. There is a chance we might be repeating that process. I have 
not been able to find any verification such a method works reliably. As a 
matter of fact, everything I read generally comes with cautions that pretty 
much say it is better than nothing.

There is good reason to question whether sticking probes a foot or two into 
the ground just a small distance apart results in anything meaningful when 
skin depth is many meters.

When I found N6LF's papers, I see he gives some cautions and also the only 
verification seems to be that one method using shallow probes roughly agrees 
with a slightly different method using probes. This really, if we think 
about it, is not verification at all.

The major problems that concern me are probe to soil contact and soil 
resistance and dielectric in the disturbed area where the probe(s) is 
inserted, and the fact we are not measuring anything but the very top layer. 
The top foot or so might be great on VHF, but if soil in non-homogeneous 
through the skin depth of many meters I don't see what anyone hopes to learn 
with a top sample.

As a matter of fact, N6LF suggests digging down and repeating measurements.

I wouldn't put much value on what goes on in the first foot or two on 160 
meters, unless moisture and soil remains the same for 50 feet down or the 
soil is exceptionally high conductivity. I agree with ON4UN. I think his 
statement is accurate. Let's not mistake forcefulness with logical, because 
even N6LF includes cautions.

If there is reasonable verification anywhere, where is it? Verification of a 
method is not checking two very similar methods against each other, as we 
all should know.

73 Tom