Richard Clark wrote:

Hi OM,

As stated previously:

"Fig. 6 shows the actual current in the earth for the same conditions"

I hope the word "actual" is not subject to recourse to the IEEE
dictionary for clarification.

I agree with Richard Fry. All the references to ground conductivity,
including Figure 6, are in Part II, the (erroneous) theoretical
treatment. As for the "actual", look back a page, to page 759, at the
bottom, where they say, "Thus from [equations] (8), (9), and (10),
together with Fig. 4 ["Calculated Values of Total Earth Current"], we
may obtain the actual current in the earth and the current in the
wires." So the "actual" current is calculated from three equations and a
graph of calculated current. Whatever they might have meant by "actual",
it doesn't mean that it was measured.

The "same conditions" are explicitly specified with conductivity.

One has to trust that engineers did not ask the farmer's wife to make
this determination for them in her kitchen. The imputation of
distrust would seem to serve another agenda.

Figures 7, 8, 9, and 10 also are all quite explicit.

They are also part of the theoretical treatment and don't represent
measured values. Measured values begin with Fig. 25.

. . .

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.

Roy Lewallen, W7EL

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

Richard Clark wrote:
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.

Sorry, as so often happens I missed your point entirely. If you're
interested in having me understand what "circularity" you mean, you'll
have to be more blunt and pedestrian so I'm able to understand it.


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.

Again, I haven't a clue what you're talking about. Arguing semantics, I
suppose, in which I'm afraid I have no interest.

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.

I'm missing this one, too. If you're saying that those three graphs are
of measured data, I can present what I believe is a good argument
against that premise. But I can't tell if that's what you're saying or not.

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 wouldn't surprise me a bit if the theoretical work was written or
modified after the measurements were made, which I believe is what
you're saying. That doesn't alter the fact that the graphs of Part II
are from calculated rather than measured results.

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.

I'm not sure what you mean by "derived from", but they sure aren't
graphs of measured data. For starters, some of those graphs are for 1
MHz, while according to the paper all measurements were made at 3. For
another thing, I'm sure they didn't have the ability to change the
ground conductivity; some of the graphs are for different ground
conductivities than others. Finally, compare Figures 7 and 8 with Figure
42. The latter is from measured results, as explained on p. 781. It's
quite different from the theoretical results for Figures 7 and 8.
Incidentally, the theoretical analysis, including Figures 7 and 8, seems
to assume infinite radial length, which is another difference between
the theoretical and measured conditions (besides ground conductivity
and, in some cases, frequency).

The text clearly states this: "The antenna heights given here
were chosen to conform to later experimental heights."

That's a very reasonable thing to do, when presenting both theoretical
and measured results. I believe you're drawing conclusions from it which
are well beyond its straightforward intent. (Perhaps this is due to your
English literature background? It certainly was one of the activities
overwhelmingly emphasized and encouraged in all English lit courses I
ever took.)

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.

Even that isn't blunt enough for me. Sorry. I did badly in English.

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

If you say so. Whatever you said.

Roy Lewallen, W7EL

On Tue, 09 Aug 2005 18:43:19 -0700, Roy Lewallen
wrote:

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

If you say so. Whatever you said.

Hi Roy,

It must have taken great effort of will to come to that conclusion.
Your achievement is noted as has all the groaning along the way.

73's
Richard Clark, KB7QHC

On Tue, 09 Aug 2005 18:43:19 -0700, Roy Lewallen
wrote:
Sorry, as so often happens I missed your point entirely. If you're
interested in having me understand what "circularity" you mean, you'll
have to be more blunt and pedestrian so I'm able to understand it.

Hi Roy,

You consistently demur expertise in English, and you are equally
troubled in Blunt, but the plea for help cannot go unanswered.

Let's see, we have a premise that the ground conductivity was
concocted from formula for the BL&E paper. If we proceed along the
lines this is true, then we immediately are faced with the conundrum:
ground quality of a field in New Jersey in the wintertime.

How was this determination made? When was this determination made?
What was the determination made? Oh well, all such quantitative
discussion is missing so the statement appears to have as much basis
as a guess, but we are faced with the complaint holding Reggie to a
higher standard:
Your program fails badly with any reasonable ground conductivity and
permittivity.
compared to what determination? Where? of What? by Whom?

This appears to be a war of wills between the best guessing software.

Can we presume the answers lie with:
Brown, Lewis, and Epstein did a good and careful job of measurement.
which, by the leading hypothesis contains no measure of conductivity?

So the objection to Reggie's software not conforming to results
offered by NEC-4 is proven by:
NEC-4 does pretty well with reasonable assumptions for the
ground quality of a field in New Jersey in the wintertime.
a strained appeal through BL&E,
NEC-4 matches their results quite well
which, by the leading hypothesis contains no measure of conductivity.
Which from FCC charts would suggest it to be uniformly dismal.

I've seen no discussion of actual quantifiable results against these
claims offered, so there is every chance that they are pinned together
by the evident circularity:

1. There has been no measurement of ground conductivity by BL&E
2. Reggies model for ground conductivity counters NEC-4
3. NEC-4's model for ground conductivity conforms to BL&E
4. There has been no measurement of ground conductivity by BL&E

I would like to see:
Your program fails badly with any reasonable ground conductivity and permittivity.
supported by something other than appeals to dead white engineers -
Reggie has a patent on that method already.

73's
Richard Clark, KB7QHC

Reggie has a patent on that method already.

73's
Richard Clark, KB7QHC

================================

Yes! It doesn't take much to get Roy to lose his temper and resort to
a frustrated attempt at character assassination.

Well, sadly, that's the end of the Bible. Between you, after 68
years, you experts have finally shredded it. ;o(
----
Reg, G4FGQ

"Richard Clark"
I've seen no discussion of actual quantifiable results against these
claims offered, so there is every chance that they are pinned together
by the evident circularity:

1. There has been no measurement of ground conductivity by BL&E
2. Reggies model for ground conductivity counters NEC-4
3. NEC-4's model for ground conductivity conforms to BL&E
4. There has been no measurement of ground conductivity by BL&E
_________________

At least now you admit that BL&E didn't measure ground conductivity. That's
progress.

First things first. The goal of BL&E's experimental work was to relate the
'efficiency' of MW vertical radiators of various electrical heights to
radial ground systems of various configurations. It did not state or find
that ground conductivity had any significant bearing on this, and, as shown
by their measured results, it did not.

The entire theoretical section of this paper where ground currents are
calculated, and the references to ground currents that were measured during
the experimental work could have been omitted both from consideration and
measurement without changing the conclusions of the paper. None of that was
significant to their measured results for field strength vs system
configuration, which was the purpose of their efforts. And omitting it
would have spared you your confusion.

The FCC considers every non-sectionalized AM broadcast vertical radiator of
a given electrical height using a given radial ground system to have a given
efficiency. Period. Ground conductivity at the radiator site has nothing
to do with that. It doesn't matter whether that site is in the middle of
Kansas with 30 mS/m conductivity, or on Long Island with 0.5 mS/m, radiation
emitted from a given antenna+radial ground system will be the same. The
purpose of the BL&E field work was to determine those efficiency values, and
it did so with high accuracy. Their findings have been a benchmark
confirmed at many hundreds (probably thousands) of AM broadcast station
applications since 1937.

By the way, even NEC-2 can be used to confirm the results of BL&E's study,
by inserting at the bottom of the vertical radiator a low-value DC
resistance simulating the resistance of the radial ground system connection
with a perfect ground plane. This again shows that ground conductivity is
insignificant in determining the radiation 'efficiency' of a MW broadcast
vertical and its radial ground system.

RF

"Richard Fry" wrote
At least now you admit that BL&E didn't measure ground conductivity.
That's
progress.

================================

Admit it ? You got me wrong!

I was the FIRST to point it out many months ago. I did it politely by
blaming BL&E's poor memory.
----
Reg, G4FGQ

"Reg Edwards"
"Richard Fry" wrote
At least now you admit that BL&E didn't measure ground conductivity.
That's progress.

Admit it ? You got me wrong!
I was the FIRST to point it out many months ago. I did it politely by
blaming BL&E's poor memory.
___________________

Note that my post responded to the comments of Richard Clark,
not to yours.

Now if YOU will admit that there was no reason for BL&E to have measured
ground conductivity for this study, and quit saying that they "forgot" to do
it--that will be another victory for reality.

RF

On Tue, 09 Aug 2005 19:41:54 -0700, Richard Clark
wrote:

Let's see, we have a premise that the ground conductivity was
concocted from formula for the BL&E paper.

On Wed, 10 Aug 2005 07:33:37 -0500, "Richard Fry"
wrote:

At least now you admit that BL&E didn't measure ground conductivity. That's
progress.

Hi OM,

Admission indeed, this is a consistent strain of interpretation along
with the remaining embellishment that is unresponsive to the post.

73's
Richard Clark, KB7QHC