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On Mar 11, 8:42 am, "John KD5YI" wrote:
"Art Unwin" wrote in message ... On Mar 8, 12:25 am, "John KD5YI" wrote: "Brian Kelly" wrote in message ... On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message .... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill, page 12. Begin quote Regardless of antenna type, all involve the same basic principle that radiation is produced by accelerated (or decelerated) charge. The basic equation of radiation may be expressed simply as IL = Qv (A m / s) where I = time-changing current, A/s L = length of current element, m Q = charge, C v = time change of velocity which equals the acceleration of the charge, m/s Thus, time-changing current radiates and accelerated charge radiates. For steady-state harmonic variation, we usually focus on current. For transients or pulses, we focus on charge. The radiation is perpendicular to the acceleration, and the radiated power is proportional to the square of IL or Qv. end quote Cheers, John John If Kraus said "The radiation is perpendicular to the accelleration" then the book is worthless. Review the scalar quantities of a radiator. It is impossible for the resultant to be at 90 degrees to the antenna axis. I suspect the roots of this untruth was the invention of the planar antenna. For maximum horizontal radiation a radiator will be around 10 degrees out of parallel to the earth surface, not parallel. The king is dead, long live the king. Old books just cannot keep up to date Regards Art ie the yagi Art - I was actually replying to W3RV. However, since you piped up... Have you had any books on the subject published? How about research papers? Anything published at all? Do you have any presentations with equations prepared to support your claim? To which companies have you sold your expertise in this field? Have your taught any classes? It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. Cheers, John Let's keep to the subject and put the other comments aside. Do you have any antenna computor programs that you have confidence in? What are they so I can give you thr figures to prove it to yourself Art |
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