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#571
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On Jan 3, 1:56*pm, Cecil Moore wrote:
Keith Dysart wrote: So there is NO reference that claims that the output impedance can not be used to compute the reflection coefficient. If I say I am not going to look for a reference to "creation" in The Bible, are you going to assert there are no references to creation in The Bible? Good luck on your ridiculous assertions. You do seem to like to clip the important bits. It was your sentence: "If there was a reference, Mr. Maxwell or Dr. Bruene would have reported it by now but their argument continues to rage" that made it clear you did not expect to be able to find a reference. So that settles it, then. And that was what settled it. No expectation of a reference... Then no reason for you to argue further. ...Keith |
#572
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On Thu, 3 Jan 2008 07:55:48 -0800 (PST), Keith Dysart
wrote: The presence of this poster providing misleading information makes this group a rather unique learning environment. Hi Keith, By a certain opaque style of writing, the tenor of questions offered, and an aversion to to deliberating the evidence given in response; I would say the crown of Trolling is being challenged and Cecil may slip beneath a new prince's claim. 73's Richard Clark, KB7QHC |
#573
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On Jan 3, 2:15*pm, Cecil Moore wrote:
Keith Dysart wrote: Good answers. Exactly as I expected. Now please explain the applicability of EM waves to the state of an open circuited line excited with a step function, especially after it settles to a constant voltage (where only an E field will be present). Before it settles to a constant voltage, there is acceleration of electrons that results in an EM photonic wave. After it settles to a constant voltage, there is no acceleration of electrons and the EM photonic wave disappears. So when the edge of the step is travelling towards the right, is there an EM wave to the right of the step, to left of the step, at the step, or all three? Similar question for when the step is travelling back to the generator? When the line has settled, how do you add the forward and reflected wave to compute the voltage on the line, or does the disappearance of the wave mean this is now impossible? If only the step itself has an EM wave, how are voltages computed using reflection coefficient after the step has reflected from the open end? ...Keith |
#574
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Keith Dysart wrote:
clip..... I fully agree with the philosophy you express here Keith. But I can see how you would doubt that I am practicing what I just agreed with. You may have mis-interpreted my comments. I have NOT seen evidenace of the behaviour I describe above in your writings. The comments mostly apply to a single poster who has been posting on this group for many years, at least since when I first started viewing this group in the mid 90s and began to really gain an understanding of transmission lines. The presence of this poster providing misleading information makes this group a rather unique learning environment. In most learning environments, the information is neatly packaged and presented from a consistent point of view with no challenge. Here, a lot of chaff is mixed with the wheat. This has the "benefit" of forcing the learner to understand well enough to make decisions between competing explanations. The learner who makes the right choices comes out with a much more solid understanding than one who has just been (spoon) fed the story. On the other hand, some have probably been lead seriously astray. For sure, I have a better understanding than I would have had without the challenging misleading information. So for sure it would be better for the poster in question were he to let go of some of his incorrect beliefs, it would also reduce some of the opportunities for learning provided to others lurking or partaking in the discussions. ...Keith Thanks Keith. I am learning a tremendous amount here. As you say, the interaction really helps focus, reason, and justify, and finally, readjust thinking as understanding improves. I certainly like your example of two opposite traveling pulses. I used it again today in a posting responding to Roy. 73, Roger, W7WKB |
#575
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Keith Dysart wrote:
Please describe the final state of the step excited open circuited line using photons. Photons are emitted and absorbed by the electrons as the electrons lose/gain energy. Photons are not conserved. Only the energy in photons is conserved. In a DC system with no accelerating or decelerating electrons, all of the photons have been absorbed back into the electrons (or lost to radiation). Of course, this describes an ideal system. -- 73, Cecil http://www.w5dxp.com |
#576
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On Jan 3, 2:10*pm, Cecil Moore wrote:
Keith Dysart wrote: Excellent. So there is NO reference that claims that the output impedance can not be used to compute the reflection coefficient. That is probably a false statement. I just haven't wasted my time looking for a reference that uses those exact words. There are many references that do. I seriously doubt that they say what you are asserting. Please produce those references. One has been directly provided, though many more are available using the google searches previously suggested. But that one is infinitely more than those available supporting the opposite view. In another thread, I proved your assertion wrong. Asserting that you have proved an assertion wrong is not the same as proving it wrong. A Bird wattmeter placed at the output of your source will read forward power = reflected power. The reflection coefficient can be calculated from that. rho = SQRT(Pref/Pfor) = plus or minus 1.0 Of course. With one side of the Bird wattmeter left open, it will happily measure the reflection coefficient of that open. This says nothing about the reflection coefficient of the line connection with the source. ...Keith |
#577
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On Thu, 03 Jan 2008 12:25:59 -0600, Cecil Moore
wrote: The presence of this poster providing misleading information makes this group a rather unique learning environment. For the record: The only controversial assertion that I have ever made is that coherent EM wave cancellation can cause a redistribution of the EM energy in the opposite direction in a transmission line. No one has proved that assertion to be wrong. What an ego to rush to slip into a TNT vest in the hope of being associated with Nobel. As usual, Cecil's arguments are so script driven, that I cannot pass up this mocking opportunity: I shall assert that coherent EM wave cancellation can not cause a redistribution of the EM energy in the opposite direction in a transmission line. No one has proved that assertion to be wrong. Does that misleading statement qualify me for Keith's anointed villain of the group? Cecil certainly has described me as being scurrilous enough to so qualify! ;-) Besides, I think I look better in that vest than he does. 73's Richard Clark, KB7QHC |
#578
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Keith Dysart wrote:
It was your sentence: "If there was a reference, Mr. Maxwell or Dr. Bruene would have reported it by now but their argument continues to rage" that made it clear you did not expect to be able to find a reference. Make that *easily* find a reference and you will have it correct. Just because I am lazy is not a proof that the reference doesn't exist. And that was what settled it. No expectation of a reference... Then no reason for you to argue further. Just a minute. What about the proof I offered that the actual reflection coefficient is 1.0 based on Bird wattmeter readings? The Bird tells us that at the source terminals, the forward power equals the reflected power. rho = SQRT(Pref/Pfor) = plus or minus 1.0 -- 73, Cecil http://www.w5dxp.com |
#579
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![]() Cecil Moore wrote: Mike Monett wrote: The term "bounce" means they interact. Electromagnetic signals do not interact. They superimpose. Each is completely unaware and unaffected by the other. Except when they are coherent, collinear in the same direction, equal in magnitude and 180 degrees out of phase. Fabricated nonsense. Thensomething permanent happens as signified by the s-parameter equation. b1 = s11*a1 + s12*a2 = 0 s11*a1 and s12*a2 are coherent, collinear in the same direction, equal in magnitude and 180 degrees out of phase. Their combined energy components are redistributed in the direction of b2 = s21*a1 + s22*a2 Squaring the above equation results in the power density irradiance equation from the field of optics. Preflected = (b1)^2 = (s11*a1)^2 + (s12*a2)^2 + 2*s11*a1*s12*a2 = 0 micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/waveinteractions/index.html "... when two waves of equal amplitude and wavelength that are 180-degrees ... out of phase with each other meet, ... All of the photon energy present in these waves must somehow be recovered or redistributed in a new direction, according to the law of energy conservation ... Instead, upon meeting, the photons are redistributed to regions that permit constructive interference, ..." That certainly sounds like an "interaction" to me. But to truly be considered official proof of an interaction, it must walk like one as well as sound like one, IIRC. :-) ac6xg |
#580
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On Thu, 3 Jan 2008 10:28:07 -0800 (PST), art
wrote: When current gets to the top of a fractional wave antenna it just does not turn back. It has to wait until half a period time has elapsed Guru Prior Art, sir, Which is more rankling to your celebrity: 1. being ignored for such stupid remarks; 1. being criticised for such stupid remarks? To reduce confusion, select 1 of the above in response. 73's Richard Clark, KB7QHC |
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