On Wed, 12 May 2010 22:06:49 -0700, Richard Clark
wrote:

Little might have changed since, except that the fluorescence of
newsgroup gurus have enlightened modern civilization with advances in
accuracies now verging on ±6dB where the pre-eminence of water has
been overthrown in favor of photon-stream control. The binary search
that was formerly the cornerstone of modeling has been replaced with
the unary declaration that is self-proven by having been uttered (or
posted to a group that has a vague resemblance to the topic). Hence,
the inaccuracies of coins has been wholly removed to yield perfect
understanding (within ±6dB, of course).

That's a fair description of the digital part of antenna design, but
prior to the invention of computing, all such antennas were analog in
nature. The ancient pagans, that found the ideal size and shape of
trees necessary to obtain the attention of the gods were using analog
cut-n-try techniques. Given sufficient time and trees, the design was
eventually optimized.

Somewhat later, the Romans and Greeks discovered that the E and H
directions, the ratio of which was defined by the golden section.
Again, this was not a digital model, but determined with analog
techniques. Once the ratios were accurately determined, the resultant
telephone pole like structure could be used for everything from art to
executions. One of the reasons the Roman Empire lasted so long is
that they didn't have a symbol for zero, thus avoiding the divide by
zero problem. In any case, the design was demonstratively functions,
as installing the design on a hill top, would invariably draw
lightning.

After about a millennium, people started running out of hilltops and
tall trees, and found it more convenient to produce their own
lightning. The previously functional structures were wrapped in
metallic wires and waved around a magnet, thus resulting in home made
lightning. Calculations were again attempted, but since the zero had
been invented, none of the math would work. Once again, civilization
rested on the tried and true analog method of cut-n-try.

Modern antenna design followed the same analog patterns. With the aid
of the analog slide rule, accuracy could be improved to about 2
significant figures. That worked fine until the invention of the
digital computer. Suddenly, 2 sig fig was not enough. The digital
computer could calculate to amazing levels of precision and suddenly
everything had to conform to this standard. Instead of "cut to fit"
and "tweak and tune" it was now necessary to justify the cost of the
new digital computers with absurd accuracies. Good enough lasted only
until the next model computer.

So, here we are, debating the relative merits of the umpteenth decimal
place, splitting hairs multiple times, and digitally modeling to
quantum levels. While useful for justifying the computers, the
resultant antennas look roughly the same as the old cut-n-try models
designed with an analog slide rule.

Whatever your vision of modeling history, one historical observation
remains constant. One must always suffer before enlightenment and
this newsgroup provides that function.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558