On Wed, 26 Nov 2008 14:49:06 -0800 (PST), Richard Fry
wrote:

When I
use their distance of a mile, I get 188 mV/m, all else identical.
Their paper reports by formula that I should see 194.5 mV/m. ...

No, the BL&E paper (accurately) stated that 194.5 mV/m is the
theoretical maximum field possible at 1 mile for 1 kW radiated by a
perfect 1/4-wave monopole over a perfect ground plane. The peak
values they measured came very close, but never quite achieved that
value.

No? No what? Is your rejection rhetorical? a dramatic conceit? Is
there some cognitive gap between "by formula" and "theoretical" you
are trying to mine? To what purpose?

Are you demanding an exact accounting between measured vs. modeled? If
so, my model comes within 2mV/m of their graphed data (which, in its
own right, does not mean they actually measured that particular
cardinal point but as it encompasses their explicitly stated variables
is tantalizingly close enough). Expectations of accuracy performed in
the field for a continuum of points (verging on 1%) for a fabricated
argument of more/less is seeking advantage where there is no salvation
to be found.

It would appear that with the average of the two distances, my model
accords quite closely to BL&E.

Mr. Clark - kindly note that in your first quote above you say that,
if anything, "modelers" show MORE response than BL&E Then when
pressed a bit you say that your model "accords quite closely" with
BL&E.

There is more than one model involved as described by BL&E. I
explicitly selected from one of several available - all of which I
have modeled. The model I describe conforms to far more of their
variables available than those expressed by you. It also exhibited
more response than your 1kM touchstone. Is this touchstone derived
from BL&E or some other source unknown to all here, but you? It seems
when I followed your offering, you want to challenge its authority.

Those two data points I offer exhibit variations of barely a quarter
dB about the touchstones you supply (one available from BL&E), and
which you fall considerably short of in your own effort. Their
average around these touchstones average is an amazingly small
difference. The difference between the model I selected, and the one
they report (one in the same) is on order of 0.1dB. If this does not
constitute an accord, then I would suggest you have more water to
carry than myself to turn modeling results into congruency. I am not
particularly motivated to improve things when my experience suggests
that it is a fool's mission given it implies accuracies that were
beyond what was achievable in that cold winter field, 70 odd years
ago.

Yet the results of my EZNEC near-field model showed considerably LESS
ground wave field at 1 km than either the FCC approach or the BL&E
data.

Clarifications, please?

You don't provide enough detail of your model to be able to point to
anything in error, but by the multitude of your statements, it doesn't
sound like you have spent enough time in the practice of modeling. The
rest of my discussion below hardly reveals anything beyond the obvious
- for one versed in the craft.

My models were arrived at through the simple, but tedious craft of
close reading and conforming to expressed facts in the literature.
Some art was involved in the selection from a choice of grounds, for
which such choice drives a wide variation of results. Does this sound
familiar? Even there, calling it art denies the information supplied
by photographs revealing a very commonplace description: Pastoral. My
choice of ground characteristics, if anything, hardly exhibits a
radical departure. In fact I choose no other ground than average for
the vast majority of my modeling. Within the confines of the
abilities of the model to support buried wire, that was performed by
suggestions offered in the help manual (clarity is achieved in reading
that too and is generally obtained in the course of considerable
exposure to the toolset). Here, the radials hovered less than half an
inch above ground instead of buried six inches beneath. Perhaps this
explains the remaining 0.1dB variation, but I doubt it. To infer such
tight coupling between model and measure is a fantasy only Art would
embrace to prove we can't trust established theory.

73's
Richard Clark, KB7QHC