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Richard:
[snip] To how many places? Your question is rather oblique when we are discussing near fields and antenna as "transducer" [not a choice of term I subscribe to]. [snip] OK, ok... you've busted me... I admit that circuit theory is on really shaky ground. Although circuit theory was developed by Ohm, Kirchoff and others before Maxwell presented the world with his celebrated equations, we can all agree that circuit theory is a very poor (one dimensional) approximation to field theory. Circuits are a thoroughly useless affair dealing only with poorly understood approximations to the "real deal"...waves! I admit it, there is no such thing as "voltage", which after all is only the value V of a definite line integral of the vector field that depends upon the somewhat arbitrary path of integration, chosen by the integrator, through the appropriate E field, and so consequently there is no such thing as a "real" driving point impedance Z = V/I. The only reality is the characteristic or wave impedance! There I've said it! So... youv'e got me... I agree... we should not really be messing about trying to define phoney "transducer" functions between circuit theoretic variables (V, I) and wave theoretic variables (E, H) since the former have such an ephemeral existence. Still in all... one wonders... do circuits and waves, charge particles (electrons) and waves particles (photons) have any truck with each other or... do they lead entirely separate lives? What would you call the intermediaries between reality and approximation? I'm very sorry to have brought up the subject... I've probably confused the OP, and I am here and now prepared to recant my heresy, before you light the kindling beneath my feet, heh, heh... I solemly swear that an antenna is not a "transducer" between circuits and waves! (grin) But... ahem... the sun still has spots! Kathy, bring me another glass of that Rivaner! Molly Bloom indeed! -- Pete K1PO Indialantic By-the-Sea, FL I seriously doubt that you've unhinged from the origins of that value, however, it bears only tangentially on the matter. That is an antenna itself has no effect on the fundamental u and e of the media in which it is immersed. Wrong. [snip] Surely uo, eo, Zo and c (velocity of light) are fundamental and invariant properties of "free space", no? And some toothpaste makes our teeth whiter, no? Your reply does nothing to answer your error, however. [snip] After all the antenna is very small, and free space is very large (grin), and so a tiny antenna cannot change u and e everywhere! Abstracting from near space to everywhere is the source of your error. [snip] No, I'm "contracting" from outer space to near space... using the contravarient tensor! Then you have misapplied it, clearly. Arguing does not take the place of easily demonstrable facts. AH! forgive me, wrong forum, arguing is classic substitution. However, the entertainment value is rather poorer this round. There might just also be plane waves passing through identically the same region of space, say emanating from a more distant antenna. Wrong. [snip] Oh, and here I thought that at least tiny remnants of all radiation eventually passes through every part of space, filling all of space as it expands throughout the Universe.. Are "thoughts" related to "beliefs?" Bloated speculations of background radiation don't change the basic assertion that in the near field, there is nothing that remotely approaches the presumed 377 Ohm specification. You've both (earlier) acknowledged this and (have since) challenged it with a semantic fog such as: I know that Special Relativity [Maxwell's equations] is not supported in full by General Relativity, but surely even though space is warped by mass, superposition must still be supported. The radiation in your neighbourhood is a superposition of suitably delayed and reduced (by path attenuation) of all radiation, no? EZNEC demonstrates the violation of your "beliefs," yes? I miss Reg Edwards already :-( Certainly you're a poor substitute for Punchinello. (and Kelvin is winding up a pitch to wing a chunk of chalk off your noggin.) 73's Richard Clark, KB7QHC |
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