View Single Post
  #7   Report Post  
Old November 15th 07, 12:29 PM posted to rec.radio.amateur.antenna
Mike Kaliski Mike Kaliski is offline
external usenet poster
 
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 02:47:05 -0000, "Mike Kaliski"
wrote:

It seems that everyone was so busy laughing on this newsgroup,


Hi Mike,

As well crafted a line for trolling as any....

that no one
has actually provided any information as to whether any detailed research
has ever been carried out as to what is going on within the radiating
elements of an antenna.


This, as the lawyers would say, argues a fact not yet in evidence.
Your statement appears to be one that can only be satisfied by meeting
a string of conditions:
1. The actuality of "actually," who is the arbiter of this? This
group has long experienced denial by inventors that their theories
have never been "actually" disproved. "Actually" is one of those
rubbery words that fits any argument that lack definition;
2. "detailed research?" Another qualifier that invites the rejection
of any contribution for lacking unspecified requirements;
3. "what is going on?" Now THERE is a technical goal for detailed
research to be provided as information.
4. "within the radiating elements?" Is this to presume there is some
distinct radiation from "within" elements? This would be a remarkable
measurement achievement to tease it out from the rest. [Could we use
a Gaussian sieve?]

There is loads of theory in the text books, but I


If you moved to the fiction shelves would you say there is loads of
drama in them? [More to the matter, what would you expect?]

have yet to see any empirical measurements or results.


Of what? Actual detailed results of what is going on within radiating
elements?

Help us out here. What instrumentation would be used? What units of
measure would be employed? (In "what is going on" are we talking
about Ohms, Volts, Amperes; or swimming, having a party, or getting
laid off?). What qualifies as detail? How would we recognize it
being actual?

I am aware of the
research into small loops carried out by Professor Underhill (also
published
in RadCom) but it seems that even his results have been disputed.


Hmm, tantalizing, but how do small loops relate to "what is actually
going on?" More so, where within the loop did Professor Underhill
make his measurements, and what were they of? [I might point out
here, editorially, that little content was posted by you up until this
point, and it has evaporated following its solitary mention. If you
stripped out everything, and simply fleshed out this sentence into a
paragraph, it might be meaningful.]

I may have submitted the post, tongue in cheek


Then the joviality that your post heralds is merited, isn't it? This
is called leading with your chin.

, to stir things up a bit, but
on reflection there seems to be something of merit in the idea.


As your post seems to be wholly unrelated to the topic, and apparently
a stream of consciousness from another thread, then this idea is
adorned with rather vague suggestions.

73's
Richard Clark, KB7QHC


Hi Richard

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.

The small transmitting loop efficiency experiments were carried out using
thermographic imaging to try and identify areas of heating within the loops.
The areas with maximum heating would indicate high current flow or high
resistance. 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. The
methodology and results of the experiment were challenged and Chu theory
seems to have won out, at least for the time being.

I don't see that there would be any need to invoke non standard units for
experimental measurements, ohms, amps and volts should suffice. I have not
worked out the best measurement methods or instrumentation to use, but I am
sure that existing equipment and techniques will suffice. 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.

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.

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.

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.

Regards
Mike G0ULI