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![]() "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 |
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