> For example, I am quite confident that the CFA antenna
> does not work as its inventor describes. Nevertheless,
> that inventor is a Chartered Engineer and academic
> with considerable practical and theoretical knowledge
> of antennas who was assisted by PhD students.
Then he and his assistants missed a very basic point at the
root of what causes radiation.
This goes along with my viewpoint. We are losing the basics.
If they had a grasp on basics or a good feel for how EM
radiation works and how to test an antenna the nonsense
never would have started.
> a new idea overtake reality. The same can be said for
> the (continuing) disagreement between (different)
> academics over the practical efficiences of small loop
> antennas.
The QST article simply had the polarization of the loop
wrong. Even though they quoted Terman, they didn't follow
what Terman said. There is nothing esoteric or difficult
about finding data, measuring, or modeling the polarization
of a loop. They should have caught the error in their on the
air comparisons if they had any idea at all how to compare
two antennas.
The editor inserted a note that used nonsense wording. Why
would an editor say something when he doesn't know the
meaning of the words? Polarization is a very simple basic
concept. When we talk about polarization we consider the
electric field plane. A vertically polarized antenna has a
vertical electric field, a horizontally polarized antenna a
horizontal electric field. The "E-field oriented" phrase
doesn't mean anything. Maybe he meant vertically polarized
(perhaps he had the E in E-field confused with the e in
elevation and not the e in electric) but this is pretty
basic stuff. The only reasons vertically polarized antennas
are more sensitive to noise is they generally are
omni-directional along the horizon, vertically polarized
antennas generally have a response peak along the horizon,
and vertically polarized ground wave signals are not
attenuated as rapidly by the earth. So a vertical has a
less-attenuated and wider overall "view " of the hundreds of
random terrestrial sources that generate noise in urban
environments.
This goes back to my viewpoint. We are losing a grasp of the
very basics that are the foundation of why or how things
work.
>There have been many other examples, but it
> is (just) conceivable that one day somebody will
> invent an efficient hf antenna that happens to fit in
> a cornflake box. We have to be careful that if that
> happens the idea is not rejected out of hand by a
> reviewer who perhaps knows less about the subject than
> the inventor.
I fully expect in a few years to open a box of cornflakes
and pull out an antenna that clearly violates the basic
principles and rules charges and fields must always follow.
After all, the salt water jug and pie pans have kept the
fellow down the road safe from lightning.
> I grieve the fact that none of the amateur radio
> magazines regularly present the sort of technical
> article that was commonplace a few years ago. But I am
> sadly certain that I am in a small minority.
I think a large part of the problem is it has become
unfashionable to point out mistakes and unfashionable to
admit making them, and uncommon to discuss disagreements on
a purely technical level. That, along with the fact we don't
follow good scientific approaches in experiments, allows
gross errors to get out into the mainstream.
It seems all big antenna mistakes come from lack of basic
simple knowledge and use of sloppy measurement techniques.
This allows "emotional" inventions. The CFA, EH antenna,
Fractals, that vertical up in the northeast USA, the CTHA
antenna, and so on all fit this mold. They would never have
gotten off the ground if the inventors understood basics or
used good verification or measurement methods.
73 Tom
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