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
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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