On Tue, 09 Aug 2005 15:07:21 -0700, Roy Lewallen
wrote:
Whatever they might have meant by "actual",
it doesn't mean that it was measured.
....
Brown, Lewis, and Epstein did a good and careful job of measurement.
Please be careful not to confuse their not-so-good theoretical treatment
with their measurement results.

If I compare this with

On Tue, 09 Aug 2005 15:25:37 -0700, Roy Lewallen
wrote:
Considering that Brown, Lewis, and Epstein's experimental work has held
as being valid for about 70 years now, it can be used as a test for
various attempts at calculating ground system losses. NEC-4 matches
their results quite well; your program produces results which are
dismally different. Anyone armed with both the BL&E paper and your
program can see for himself.
....
Your program fails badly with any reasonable ground conductivity and
permittivity. NEC-4 does pretty well with reasonable assumptions for the
ground quality of a field in New Jersey in the wintertime.

leads to amusing circularity which I will set aside.

One might well suppose that through fine parsing, "actual" is not, and
is code for "might be." All reasonably argued, but reason has been
replaced with the rhetoric of argument fighting for air.

The authors express that with their formulas (8), (9) and (10) that
results would be "accurate" which I presume parses here to "best
guess." I also note that what falls within the "theoretical"
discussion is couched with the variables set in the "measurement"
discussion. The paper, as would be expected, was written iteratively
and results were drawn back into the theory.

The theoretical discussion of radial counts does not proceed from a
natural 15, 30, 60, 113 progression - this is plainly ad hoc
determination. Nor does the theoretical discussion of antenna height
proceed naturally through 22, 44, 66, 88, and 99 degrees - again
arrived at by ad hoc methods. All such "theoretical" considerations
are the happenstance of what was available in the field. It is
overwhelmingly obvious that Figures 4 through 14 are derived from the
3MHz tests employing antenna sections of 20', 20', 20', 20', and 10'
which fall right on the curve at the 1.098 degrees per foot of section
used. The text clearly states this: "The antenna heights given here
were chosen to conform to later experimental heights." This admission
precedes the introduction of ground conductivity, and yet after all of
this ad hoc conscription from the field flows the presumption that the
ground conductivity is derived. To put it bluntly, the data and
system variables inhabit the theoretical discussion like a glove.

Like a political promise, the embraced vague genesis of ground
conductivity has been heralded for every purpose but what the authors
put it to.

73's
Richard Clark, KB7QHC