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Old February 24th 05, 07:22 PM
Roy Lewallen
 
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Reg Edwards wrote:
. . .
It is generally accepted that ground loss increases as resistivity increases
above that of salt sea water. But this cannot be universally true. Taking
the extreme case of soils which approach insulators (solid granite rock and
arid desert sands) it is obvious soil loss falls again to very low values.

There MUST be values of resistivity at which soil losses are at a maximum
but which reduce at higher values of resistivity.

Here we are concerned with buried ground radials. It is submitted that
maximum ground loss occurs at lower soil resistance values than are
upposed - if they are supposed or imagined at all!

Suppose soil resistivity is 377 ohm-metres, not a very high value, but it
happens to completely absorb, without reflection, radio waves received from
an antenna. Is this a suitable candidate for maximum loss in the ground?

The statement, for simplicity, ignores permittivity and the angle at which
radiation strikes the ground. But you get the idea.

Has anyone any info on this subject?

Of course, I may be trolling, just to catch old-wives. ;o)
----
Reg, G4FGQ


Go to groups.google.com and look up the thread "Just a comment on losses
in the ground", in mid-January 2002, in which we both participated. The
posting I made on Jan. 13, in particular, had a fair amount of
information on the topic, but other postings in the thread are worth
reading.

Roy Lewallen, W7EL