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#181
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Roy Lewallen wrote:
But Cecil (and, I'm afraid, others) also see waves of average power and sometimes energy, which seem to follow different rules. Power and energy are scalars, Roy. Of course, scalars follow different rules. Maybe the problem is that you are trying to use phase math on power. -- 73, Cecil http://www.w5dxp.com |
#182
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Dr. Honeydew wrote:
Cecil Moore wrote: A Bird wattmeter reads 100 watts forward and 100w reflected. The current in the source is zero. The source is not only not sourcing any forward power, it is also not sinking any reflected power. What complete and utter Texas-size bullsh*t. It's obvious that the source is sourcing the forward voltage wave, and it's sucking up entire reverse voltage wave from the line. And doing it while magically expending zero energy. Perpetual motion is possible, after all. If zero power is being dissipated in the source, it cannot be sourcing the forward voltage wave and it cannot be sucking up the reverse voltage wave. -- 73, Cecil http://www.w5dxp.com |
#183
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Roy Lewallen wrote:
Unlike voltage waves, which are very well known and subject to over a century of analysis using well established mathematics and physical principles, the waves of average power follow rules which constantly change to suit the needs of the moment. The rules of waves of average power come from the field of optics and they haven't changed in many decades. You see, average power is all that light physicists can measure. They call it intensity or irradiance. To deny the body of physics embodied in optics is ignorant and ridiculous. -- 73, Cecil http://www.w5dxp.com |
#184
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Tom Ring wrote:
Roy Lewallen wrote: rules which constantly change to suit the needs of the moment. Watterson fans will recognize the rules for propagating power waves as closely resembling those of Calvinball. Hopefully some of those here will get that. I would be surprised if it's more than one in four. The rules for propagating waves of EM energy have been nailed down for generations. Optical physicists don't have the luxury of measuring voltage and current. They must necessarily measure average power density. They are quite good at it and their average power density equations are quite accurate and mature. They obviously know a lot more about EM waves than most of the posters here. -- 73, Cecil http://www.w5dxp.com |
#185
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Tom Ring wrote:
Roy Lewallen wrote: rules which constantly change to suit the needs of the moment. Watterson fans will recognize the rules for propagating power waves as closely resembling those of Calvinball. Roy Lewallen, W7EL Hopefully some of those here will get that. I would be surprised if it's more than one in four. Three out of four readers haven't yet figured out how to use Google? That's pretty grim. "Calvinball" brought about 70,000 hits, or so the results screen said. Roy Lewallen, W7EL |
#186
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On Apr 18, 8:20 pm, Cecil Moore wrote:
Jim Kelley wrote: Since you insist that waves can have an effect on other waves, then you should at least be able to detail either mathematically or phenomenalogically the effect y has on x, and x has on y as well as provide some natural process that would cause this effect. Please elaborate. Thanks. In the s-parameter equation, b1 = s11(a1) + s12(a2) = 0, the interaction of s11(a1) and s12(a2) results in wave cancellation. The effect of each wave on the other is to reverse the direction and momentum of both waves. That is what happens at a Z0-match in a transmission line. That is what happens at the surface of thin- film when reflections are being canceled. Again, the redistribution of the wave energy is certainly an interaction that wouldn't exist with either wave alone. -- 73, Cecil http://www.w5dxp.com Redistribution is an interaction....interesting. But, you were telling us about how waves interact with other waves. I'm interested to know what effect x has on y, and vice versa? We have x + y making z. So after that, tell us how have x and y changed as a result of their "interaction"? 73, Jim AC6XG |
#187
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On Thu, 19 Apr 2007 01:25:29 GMT, Gene Fuller
wrote: On 18 Apr 2007 17:03:40 -0700, Keith Dysart wrote: .=2E.Keith Hi Richard, Very interesting. I also use Agent for reading newsgroups. I copied and used Keith's long message without the slightest difficulty. Everything worked as he said it would. Wonder what is different? Hi Gene, Good question. It was just a couple of ripples in the time-space continuum perhaps. I can't put my finger on any commonality, especially for the quote above when it is distinctly outside of any association with an equal symbol. Having patched up the text files, the modeler works quite nicely. Nice piece of work. It puts the popular generic title of "____ for Dummies" to the test; because if you fill in the blank with Analog, then there is still one dummy beneath the waves at low tide. 73's Richard Clark, KB7QHC |
#188
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Cecil Moore wrote:
Tom Ring wrote: Roy Lewallen wrote: rules which constantly change to suit the needs of the moment. Watterson fans will recognize the rules for propagating power waves as closely resembling those of Calvinball. Hopefully some of those here will get that. I would be surprised if it's more than one in four. The rules for propagating waves of EM energy have been nailed down for generations. Optical physicists don't have the luxury of measuring voltage and current. They must necessarily measure average power density. They are quite good at it and their average power density equations are quite accurate and mature. They obviously know a lot more about EM waves than most of the posters here. Well, that's one who doesn't. Too bad, since Calvinball was a wondrous game. I miss it. tom K0TAR |
#189
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Jim Kelley wrote:
Redistribution is an interaction....interesting. But, you were telling us about how waves interact with other waves. I'm interested to know what effect x has on y, and vice versa? We have x + y making z. So after that, tell us how have x and y changed as a result of their "interaction"? In a transmision line, when z=0, x and y are permanently changed. Their energy components combine into one re-reflected wave. The separate identities of x and y disappear at the instant that z becomes zero. In order to measure s11 and s12, a2 is turned off. The result is: a1----| |----s21(a2) s11(a1)----| Note that s11(a1) has already reflected from the impedance discontinuity and there are no other impedance discontinuities between it and the source. Should be smooth sailing. In order to measure s21 and s22, a1 is turned off. The result is: |----s22(a2) s12(a2)----| |----a2 Note that s12(a2) has already passed through the impedance discontinuity and there are no other impedance discontinuities between it and the source. Should be smooth sailing. s11(a1) and s12(a2) are your two waves. They exist and are so measurable that their measurements results in knowing the value of s11 and s12. For b1 = s11(a1) + s12(a2) = 0, s11(a1) and s12(a2) must be of equal magnitude and opposite phase. That's exactly what happens at a Z0-match. s11(a1) and s12(a2) *never* encounter an impedance discontinuity. They are effects of a1 and a2 encountering an impedance discontinuity. The only thing s11(a1) and s12(a2) encounter are each other and that interaction completely changes those two waves. The two waves cancel and their energy components are re-distributed in the opposite direction. s11(a1) and s12(a2) never encounter an impedance discontinuity. -- 73, Cecil http://www.w5dxp.com |
#190
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Cecil Moore wrote:
Jim Kelley wrote: Since you insist that waves can have an effect on other waves, then you should at least be able to detail either mathematically or phenomenalogically the effect y has on x, and x has on y as well as provide some natural process that would cause this effect. Please elaborate. Thanks. In the s-parameter equation, b1 = s11(a1) + s12(a2) = 0, the interaction of s11(a1) and s12(a2) results in wave cancellation. The effect of each wave on the other is to reverse the direction and momentum of both waves. That is what happens at a Z0-match in a transmission line. That is what happens at the surface of thin- film when reflections are being canceled. Again, the redistribution of the wave energy is certainly an interaction that wouldn't exist with either wave alone. Cecil, Do you see the common factor in your response about "wave interaction"? In all of your examples there is an interface or some sort of discontinuity. Nobody argues that waves are forever unchanging. However, those changes take place only through interaction with interfaces or other discontinuities. 73, Gene W4SZ |
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