> W5UN did extensive A-B measurements between a collocated
> elevated radial system and an extensive, ground-mounted
> radial
> system. And Dave chose the elevated radial system for his
> 4-squares on 80 and 160.
Then that would be the very first actual A B field strength
test, if made in a clear area free of other ground
influences like old ground systems, that has ever been made
besides the one at WVNJ and the half dozen I have personally
made.
A single test like that, if it truely showed an A-B
comparison would mean more than all the articles for the
past 20 years, although not nearly as much as the thousands
of measurements RCA made in the 20' and 30's. As anyone who
has researched this knows, the RCA tests were a turning
point in antenna design. The very detailed measurements of
real systems by RCA had the effect of stopping the common
use of resonant counterpoises.
Negating that work would require at least reasonable
scientfic method and actual measurements. That's something
that has never been done to this date.
> I am reluctant to characterize Dave's extensive results
> over many,
> many months of testing although I have visited with him
> and looked
> at his arrays. The best I can do is to encourage him to
> make his
> tests public. And I know that he is very happy with his
> choice and
> the performance of his two arrays.
"Happy" isn't the issue, but data is.
1.) Prior to the 30's, virtually most systems used a
resonant counterpoise. Radials were uncommon.
2.) In and around the 1930's it was found that a system of
40-60 1/4 wave radials would get array efficiency up nearly
to the maximum possible. This was based on thousands of good
direct scientific measurements of actual test systems where
only the ground systems were changed.
3.) The study was so overpowering the FCC simply doubled the
number of radials required to get out on the flat part of
the curve, and told broadcast stations if they used that
many radials they didn't need to do efficiency proofs of the
ground system. (The efficiency proofs established a minimum
field strength, not a maximum.)
4.) Sometime in the 70's or early 80's a Ham radio article
proposed simply insulating a buried radial would increase
system efficiency. The article did not contain a single
verifying field strength measurement. Still, some people
strongly believed in that conjecture and it became a point
of debate...despite lacking any attempt of actually
measuring field strength.
5.) When computer programs came along, someone used a
program that really had no verification of earth behavior at
HF to model ground systems. That article, despite the lack
of actual field strength measurements, started the current
trend.
6.) Some BC systems, some even with unknown amounts of old
radials and other metal in place, were used to " prove" four
elevated radials would equal 120 radials. The problem with
that is anyone who understands how those tests are made also
understands they really don't measure array efficiency
change between the two systems. I've already outlined why
they really don't tell us anything useful to help resolve
this debate.
7.) Later a few articles appeared that claimed even two
elevated radials had nearly 100% efficiency. Again there was
no verification.
8.) A few years later another article appeared, again
without a single verifying field strength comparison, that
proposed the reason some elevated systems showed bad
performance was the radials were self-resonant and different
in current. That article suggested reducing the radial
length would increase the signal, but once again not a
single verifying field strength measurement was made
comparing the two systems.
This timeline has brought us to this point. We are at a
place where some people strongly think four 1/8th wave
radials, or even no radials at all, are better than 60 full
size radials...and they will argue that point endlessly.
One would think in the past 20-30 years someone who proposed
a theory that would undo the many thousands of RCA
measurements (this is Radio Corporation of America, NOT the
Radio Club of America sometimes referred to as "RCA" in
modern articles) would at least do a few dozen FS
measurements where only the radials were changed, yet there
are virtually no field strength measurements of any kind
offered!
In my opinion if someone wants to write an article claiming
something is improved and challenging the traditional wisdom
that was based on the extensive RCA (Radio Corporation of
America) studies, they should at least directly measure what
they claim is changed. Every technical article should at
least make some attempt to directly measure the parameter it
claims is being changed with reasonable logical science in
the measurements. Then when the weight of evidence shows all
the real work was wrong, I'll buy into it.
For me a technical paper or article is interesting and
valuable when it has actual data. Not when it simply makes
me feel good.
73 Tom
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