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#871
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Cecil Moore wrote:
Gene Fuller wrote: Why would something "referenced to the source phase" change when that source itself was changed? In my EZNEC examples the source current reference phase is zero and all the currents at the various points are referenced to that zero source phase. If the source current phase is changed, the phase of all the currents at the various sampling points change. In TravWave.EZ, the current is sampled by a zero ohm load in segment 10 of the wire. Source phase Seg 10 phase 0 deg -47.82 deg -10 deg -57.82 deg +10 deg -37.82 deg The current in Seg 10 is clearly referenced to the phase of the source and obviously lags the source phase by 47.82 degrees. Isn't that exactly what I said? What you are showing above is the change with respect to some arbitrary point, not with respect to the source. The antenna current phase does not change at all wrt the source. |
#872
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Cecil Moore wrote:
Gene Fuller wrote: A direct quote from AN-95-1, the slide version, is: Two-port, three-port, and n-port models simplify the input / output response of active and passive devices and circuits into "black boxes" described by a set of four linear parameters. Thank you, Gene. That contradicts what you said before about the black box not being allowed to have two of the four terminals on the other side. Play silly games with the facts and you tend to get caught. If you deny the legitimacy of "black boxes" do you need to give up the use of s-parameters? No, you need to give up your assertion that a four- terminal black box doesn't have two terminals on the other side. Your black box and HP's are two entirely different concepts. HP puts a black box around a 4-terminal network to enhance understanding of the contents of the black box. You put a black box around a stub to promote ignorance of the contents of the black box. I have said before. Specify that the black boxes be supplied with the four measured s-parameters stamped on them and I can probably tell you which box is which without even applying a signal. Or, more logically, forget the black box entirely since it is totally irrelevant to the subject being discussed. Exactly what is it that you think you have proved by using black boxes. Please be specific. I said no such thing about "black boxes" being unable to have more than two terminals. What I said is that the "black boxes" defined by Keith and Roy have only two terminals. If you want to drift off into some other irrelevant chatter, go right ahead. It might make you feel good, but it won't change the real world. |
#873
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Gene Fuller wrote:
The antenna current phase does not change at all wrt the source. That's my argument and appears to be the opposite of what you have been saying. The antenna current phase is referenced, i.e. relative, to the source phase. Are we using different definitions of the word "referenced"? Please provide your definition for "referenced". Let me say the same thing in a different way. The difference between a particular antenna current phase and the source current phase is fixed no matter what reference phase is chosen for the source current. -- 73, Cecil http://www.w5dxp.com |
#874
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Gene Fuller wrote:
I said no such thing about "black boxes" being unable to have more than two terminals. What I said is that the "black boxes" defined by Keith and Roy have only two terminals. But the "black boxes" defined by me have either two terminals or four terminals. Here they are again: --43.4 deg 600 ohm line--+--10 deg 100 ohm line--open --43.4 deg 600 ohm line--+--46.6 deg 600 ohm line--open --43.4 deg 600 ohm line--+--j567 impedor The black boxes are drawn around the '+' point just as I said before. That makes the first two examples four- terminal networks and the last example a two-terminal network. Now tell us again how s11, s12, s21, and s22 are identical for those three black boxes. -- 73, Cecil http://www.w5dxp.com |
#875
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Gene Fuller wrote:
If you want to drift off into some other irrelevant chatter, go right ahead. It might make you feel good, but it won't change the real world. As if imaginary black boxes exist in the real world. :-) Get real, Gene. Any black box you provide, I can open. -- 73, Cecil http://www.w5dxp.com |
#876
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Cecil Moore wrote:
Gene Fuller wrote: The antenna current phase does not change at all wrt the source. That's my argument and appears to be the opposite of what you have been saying. The antenna current phase is referenced, i.e. relative, to the source phase. Are we using different definitions of the word "referenced"? Please provide your definition for "referenced". Let me say the same thing in a different way. The difference between a particular antenna current phase and the source current phase is fixed no matter what reference phase is chosen for the source current. Cecil, I am sorry that you seem to be having so much trouble with the English language today. 8-) If the antenna current was referenced to the source current, the reported antenna current phase would *not* change when the source phase was changed. As you can see, the reported antenna current phase *does* change in step with adjustment of the source phase. This means that both sets of phases are referenced to the same arbitrary point, not directly to each other. This was exactly what Roy was saying, followed by your challenge of his understanding of NEC. My definition of "reference" is the ordinary definition found in scientific and technical writing. It is the equivalent of "relative to" used by you above. 73, Gene W4SZ |
#877
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Gene Fuller wrote:
If the antenna current was referenced to the source current, the reported antenna current phase would *not* change when the source phase was changed. This gives a whole new meaning to "referenced". The antenna currents are phase-locked to the source current. That's about as good a reference as one can get - being phase-locked. You, like Richard C., are obviously just pulling my leg. -- 73, Cecil http://www.w5dxp.com |
#878
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Gene is of course correct. Perhaps the difficulty with basic concepts
such as phase reference is part of the reason why Cecil finds it necessary to invent and promote his alternative theories. A moment's thought would reveal one good reason not to reference phase angles to "the source" -- NEC and EZNEC allow multiple sources, each having a phase angle chosen by the user. Roy Lewallen, W7EL |
#879
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Gene Fuller wrote:
Cecil Moore wrote: It seems that whatever part of the system you don't understand, you draw a black box around it so you don't have to understand it. Cecil, Interesting comment, especially since you frequently reference s-parameter analysis. A direct quote from AN-95-1, the slide version, is: Two-port, three-port, and n-port models simplify the input / output response of active and passive devices and circuits into "black boxes" described by a set of four linear parameters. If you deny the legitimacy of "black boxes" do you need to give up the use of s-parameters? This is simply a diversion to deflect the discussion away from the sticky questions about "electrical degrees" which his theory is unable to resolve. Phase reference is another, and we can expect more. Roy Lewallen, W7EL |
#880
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Roy Lewallen wrote:
A moment's thought would reveal one good reason not to reference phase angles to "the source" -- NEC and EZNEC allow multiple sources, each having a phase angle chosen by the user. That's true, but the discussion so far has been about single source systems. What is the phase reference when a single source is used. You say it is not the same as the source so exactly how much does it differ from the source default of zero degrees? What does the reference default to if not the phase of the source signal. Is the reference phase a user selectable option? If so, how do I select and change that reference phase without changing the source phase? I strongly suspect, based on my 20 years of user experience, that the reference phase defaults to the source phase in a single-source system. I personally have never set the reference phase to anything except the single-source phase. -- 73, Cecil http://www.w5dxp.com |
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