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Old November 15th 07, 10:54 PM posted to rec.radio.amateur.antenna
Mike Kaliski Mike Kaliski is offline
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First recorded activity by RadioBanter: May 2007
Posts: 182
Default RSGB RadCom December 2007 Issue


"Richard Clark" wrote in message
...
On Thu, 15 Nov 2007 12:29:08 -0000, "Mike Kaliski"
wrote:

Thanks for yor comments and encouragement. I can well understand your
skepticism and accept that this idea is pretty far out. As you rightly
point
out, there are a whole host of issues revolving around what is being
defined, measurement methods and interpretation of results.


Hi Mike,

OK, but this still tells me nothing of what issue you think I am
skeptical about!

The small transmitting loop efficiency experiments were carried out using
thermographic imaging to try and identify areas of heating within the
loops.


Good, that is instructive.

The areas with maximum heating would indicate high current flow or high
resistance.


More properly, their product - Watts.

This information was used to try and derive a theory of
operation and efficiency figures for the loops. The idea being to prove
that
efficiency was in fact higher than predicted by the Chu theory.


This names only one theory and doesn't actually illustrate any
differences.

The
methodology and results of the experiment were challenged and Chu theory
seems to have won out, at least for the time being.


Again, all of this is suggestive, not informative. Returning to your
earlier complaint of "detailed research" we have no details beyond
heat imaging challenging the establishment.

I don't see that there would be any need to invoke non standard units for
experimental measurements, ohms, amps and volts should suffice.


Too often, this group has to wade through "what it is not" instead of
"what it is." Tell us what specific units would be convincing for
you, as you have introduced a complaint that needs to be satisfied.

I have not
worked out the best measurement methods or instrumentation to use, but I
am
sure that existing equipment and techniques will suffice.


I have worked on a world of instruments (more than anyone here).
Believe me, that experience has NOT answered the question of the ages.

Small sampling
coils, hall effect devices, temperature measurement
probes and thermal cameras are all available at prices which an amateur
experimenter can afford, so there is no reason why these experiments could
not be carried out in a domestic environment rather then an industrial
one.


OK, by induction, I presume you are harkening back to these thermal
maps or imaging.

Well, in fact they have been done, their results have been posted to
the net and argued here. You didn't get the invitation?

Unfortunately, that contributor was arguing smaller loops, coils
specifically and the mapping was tangential to the rant. He promised
more data when Spring weather would allow him to pursue this line of
inquiry, but that was several Springs ago, and he has in the interval
chosen to -um- till the same ground.

The reason for specifying a single radiating element is because
directional
and reflecting elements absorb and re-radiate RF energy. Once the
properties
of a single element are known, then it is possible to add additional
elements and make further measurements and assessments of performance.
Since
it is already known that all the elements of an antenna interact with one
another, it is important to start with the basics and work up from there.


True, and certainly it stands to improve clarity by reducing
variables.

The choice of the word 'within' was unfortunate because I accept that
there
is nothing going on actually within an antenna element, skin effect
ensuring
that RF travels on the outside of conductors.


Plus, thermal imaging would be hard pressed to peer inside a
conductor.

So I come back to my assertion that very little detail seems to have been
published about what is happening really close in to antennas i.e. on the
actual elements making up the antenna. Loads of stuff about near field and
far field experiments, but not specific points of radiation from the
antenna
elements. It may all be a complete waste of time but at least I will have
fun and hopefully learn some new stuff doing it.


You mean you are unfamiliar with this work. I've posted my own here
to little attention, I don't think this cycle will attract much more,
but here it is:
http://home.comcast.net/~kb7qhc/ante...pole/index.htm

This doesn't actually attend your preference of thermal mapping, but
you are still vague to the point of "what is happening really close in
to antennas" (even qualified by "on the actual elements" - there's
that word actual again which lends nothing to a specification).

There is an entire field of Science devoted to this (beyond the scope
of many here who would anticipate my answer being "Fields"). This
field is called Plasmonics. Books are written about it, pictures are
taken of it, and I've sat through hours of presentations demonstrating
it. Unfortunately, this crowd of investigators, like Arthur, have
re-invented the wheel and they proclaim it is square.

The long and short of it is that you stand to become more confused,
but it could be rewarding if you wear asbestos.

73's
Richard Clark, KB7QHC


Thank you Richard,

That has helped to clarify my thinking. I know people tend to insist on very
specific language and technical terms before being willing to accept
anything new on this newsgroup. I tend to agree that this is a good thing
and resorting to woolly, imprecise or made up terms does nothing to clarify
new concepts.

I guess you are skeptical that there might be a specific point on an antenna
that matches the impedence of free space and thus radiates energy more
strongly than the rest of the antenna. This is the subject that interests me
and I intend to try and establish to my own satisfaction whether this is or
is not the case. If this can be established in a scientifically robust
manner, then I will present my experimental method, measurements and
conclusions for critical examination. I am unfamiliar with work that has
been carried out in this field, so I will carry out further searches and
reading before embarking on reinventing the wheel. Thanks for the link and
the suggestion about plasmonics and fields, I will follow up on that.

Cheers
Mike G0ULI