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#1
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Steve Nosko wrote:
From this I infer that Cecil believes that once the transient portion of the response has concluded you are in the steady state and no more reflections are occurring. Is this a correct re-statement of your belief, No, no, no. That is a re-statement of the other side of the argument from mine. I often use devil's-advocate type arguments. The definition of steady-state by the other side is pure unvarying sine waves with no noise and no modulation. Then the reflections sorta disappear into a steady-state mush of standing waves. A modulated TV signal, according to their argument, is not a steady- state signal. Within this steady-state mush of standing waves, energy never makes it from the load back to the match point. Apparently, because of the uncertainty principle, reflected energy doesn't actually exist anywhere until it is radiated or dissipated, i.e. its probability wave collapses. I have challenged them to produce a standing wave without a rearward- traveling wave but nobody has been up to that challenge. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#2
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![]() Cecil Moore wrote: Steve Nosko wrote: From this I infer that Cecil believes that once the transient portion of the response has concluded you are in the steady state and no more reflections are occurring. Is this a correct re-statement of your belief, No, no, no. That is a re-statement of the other side of the argument from mine. Perhaps he thought you believed that because you're the only one who has said it? 73, Jim AC6XG |
#3
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Jim Kelley wrote:
Cecil Moore wrote: Steve Nosko wrote: From this I infer that Cecil believes that once the transient portion of the response has concluded you are in the steady state and no more reflections are occurring. Is this a correct re-statement of your belief, No, no, no. That is a re-statement of the other side of the argument from mine. Perhaps he thought you believed that because you're the only one who has said it? It's a very condensed verion of the reams of stuff that some posters have posted over the past year. In particular, when I tried to introduce noise and modulation to prove my point, I was told that noise and modulation are not allowed during steady-state. -- 73, Cecil http://www.qsl.net/w5dxp |
#4
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Cecil Moore wrote:
It's a very condensed verion of the reams of stuff that some posters have posted over the past year. In particular, when I tried to introduce noise and modulation to prove my point, I was told that noise and modulation are not allowed during steady-state. Stands to reason. Intentionally absent from the steady state are noise, modulation, transients, and any other perturbation. It would be kinda like opening the lid of an adiabatic chamber in order to see if the internal temperature stays constant. 73, Jim AC6XG |
#5
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Jim Kelley wrote:
Cecil Moore wrote: It's a very condensed verion of the reams of stuff that some posters have posted over the past year. In particular, when I tried to introduce noise and modulation to prove my point, I was told that noise and modulation are not allowed during steady-state. Stands to reason. By no stretch of the imagination, can that be dubbed "reason". |
#6
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Cecil Moore wrote:
[snip] The definition of steady-state by the other side is pure unvarying sine waves with no noise and no modulation. [snip] I have challenged them to produce a standing wave without a rearward- traveling wave but nobody has been up to that challenge. 73, Cecil http://www.qsl.net/w5dxp Cecil, I don't plan to enter this endless argument about transmission lines, but there are a couple of points you might want to consider. * Steady state simply means that a phenomenon has no inherent reference to its time of origin. One cannot observe a steady-state wave and determine any clue about when it started. It contains no absolute time markers. A transient, on the other hand, contains direct reference information about when it was formed. There is no requirement that the steady state phenomenon is a simple sine wave. Many problems in math, science, and engineering exhibit both transient and steady state solutions. It is not clear why there is any confusion at all in this thread. * Standing waves don't require the pre-existence of traveling waves. A straightforward application of Maxwell's equations with appropriate boundary conditions for the physical environment will lead to standing waves directly. Check out one of your recently quoted favorite authors, J. C. Slater, and look at some of the resonant cavity stuff. Most definitely standing waves, but you will find lots of complex Bessel functions and darn few traveling waves. In virtually every transmission line situation proposed on RRAA, whether tuned antenna feed lines or quarter-wave stubs, the transmission line is resonant. It is possible to consider the resulting standing waves as the sum of two traveling waves, but it is equally valid to consider the transmission line as a simple resonator. The physically measurable instantaneous voltages and currents are precisely the same whether one considers oscillation from capacitive to inductive energy storage in the line or the sum of two counter-traveling waves. You often refer to wave-particle duality and to the use of S-parameters instead of lumped circuit analysis. The world of science and engineering is absolutely filled with this sort of dual description for physical phenomena. In many cases one approach will be more convenient or more intuitive, but that does not make the dual approach less valid. There's more than one way to skin a cat. 73, Gene W4SZ |
#7
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Gene Fuller wrote:
* Standing waves don't require the pre-existence of traveling waves. Please present an example of a standing wave that exists without a forward-traveling wave component superposed with a rearward- traveling wave component. -- 73, Cecil http://www.qsl.net/w5dxp |
#8
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Cecil Moore wrote:
Gene Fuller wrote: * Standing waves don't require the pre-existence of traveling waves. Please present an example of a standing wave that exists without a forward-traveling wave component superposed with a rearward- traveling wave component. -- 73, Cecil http://www.qsl.net/w5dxp Cecil, Sorry, you are not paying attention. I gave you a reference that is full of such examples. Another reference you have quoted on numerous occasions is "Transmission Lines and Networks" by Walter Johnson. Take a look on page 164. He gives a description of standing waves and then comments, "One can imagine two oppositely traveling waves, . . . " Note that he uses "imagine", not required, essential, or any other mandatory word. I do not claim the use of superposed traveling waves is wrong. However, it is merely a mathematical trick, not unlike describing a square wave as a summation of Fourier components. This is very commonly done, and it is often very useful. It does not mean that mathematically derived sub-components are somehow more valid representations of nature than the original form. 73, Gene W4SZ |
#9
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Gene Fuller wrote:
Note that he uses "imagine", not required, essential, or any other mandatory word. You know that I know, "imagine" is just an expression authors use in the remote event that there might ever be a standing wave without a forward and reverse wave. All I am asking is for you to provide just one example where standing waves are not caused by forward and reverse waves. You guys mealymouth all around that challenge but NEVER have provided a decent answer. If you are not going to provide that requested example, IMO, you have nothing to say worth listening to. So Gene, please, put up or shut up, and please stop jerking us off. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#10
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Cecil,
Wow! Struck a nerve. Must be close to the truth. I have said repeatedly that the alternative technical descriptions co-exist. I have never said that one "causes" the other. That would be folly, since we are dealing with math models, not physical cause and effect. Let me turn the arrow back to you. Give us one example where forward and reverse waves "cause" a standing wave, and then prove that it's not the other way 'round. I am not aware of any credible technical writing on the subject of cause and effect in these matters, so I am anxiously awaiting your answer. (Hint: Don't waste your time.) And as to "shut up", yes, I will now do that. Until next time . . 73, Gene W4SZ Cecil Moore wrote: Gene Fuller wrote: Note that he uses "imagine", not required, essential, or any other mandatory word. You know that I know, "imagine" is just an expression authors use in the remote event that there might ever be a standing wave without a forward and reverse wave. All I am asking is for you to provide just one example where standing waves are not caused by forward and reverse waves. You guys mealymouth all around that challenge but NEVER have provided a decent answer. If you are not going to provide that requested example, IMO, you have nothing to say worth listening to. So Gene, please, put up or shut up, and please stop jerking us off. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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