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#1
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Cecil Moore wrote:
Jim Kelley wrote: Cecil Moore wrote: I(x,t) = Imax sin(kx) cos(wt) Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole. That is correct to the same extent that t in the equation above "changes hardly at all" with time. 73, ac6xg |
#2
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Jim Kelley wrote:
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: I(x,t) = Imax sin(kx) cos(wt) Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole. That is correct to the same extent that t in the equation above "changes hardly at all" with time. t changes hardly at all referenced to the source current phase which is what we are talking about. Please don't try to feign ignorance of that fact. What I don't get is why people like you have to distort the technical facts. What do you possibly have to gain through distortion and diversion? -- 73, Cecil http://www.w5dxp.com |
#3
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Jim Kelley wrote:
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: I(x,t) = Imax sin(kx) cos(wt) Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole. That is correct to the same extent that t in the equation above "changes hardly at all" with time. The phase is referenced to the source phase, as it is in EZNEC, but you already knew that and just want to perform your usual diversions away from the technical facts. I have said at least a dozen times that the current phase I am talking about is the same as EZNEC reports. If you don't like what EZNEC reports, take it up with Roy. For those who don't understand Jim's diversion above, EZNEC sets t=zero as a reference and then reports the phase. Jim knows that and is just trying to hoodwink the uninitiatated. His motives for such remain a mystery. -- 73, Cecil http://www.w5dxp.com |
#4
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![]() Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: I(x,t) = Imax sin(kx) cos(wt) Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole. That is correct to the same extent that t in the equation above "changes hardly at all" with time. The phase is referenced to the source phase, as it is in EZNEC, but you already knew that and just want to perform your usual diversions away from the technical facts. Actually, I'm trying to figure out what technical meaning there is to be obtained from your repeated observation "Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole." The phase of the standing wave varies with position from one perspective, and with time from another, and with amplitude from yet another. If you hold t fixed, then amplitude and position remain variable. This is a revelation? I have said at least a dozen times that the current phase I am talking about is the same as EZNEC reports. If you don't like what EZNEC reports, take it up with Roy. One should be careful not to invite comparisons to a craftsman holding his tools responsible for poor craftsmanship. ;-) 73, ac6xg |
#5
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Jim Kelley wrote:
Cecil Moore wrote: . . The phase is referenced to the source phase, as it is in EZNEC, but you already knew that and just want to perform your usual diversions away from the technical facts. The current reported by EZNEC isn't referenced to source phase. The phases of all currents and voltages -- wire, source, and load -- are all referenced to the same arbitrary point. Source phase can be assigned by the user to any value relative to this point. Actually, I'm trying to figure out what technical meaning there is to be obtained from your repeated observation "Standing-wave current phase changes hardly at all up and down a stub with losses or a wire 1/2WL dipole." The phase of the standing wave varies with position from one perspective, and with time from another, and with amplitude from yet another. If you hold t fixed, then amplitude and position remain variable. This is a revelation? I have said at least a dozen times that the current phase I am talking about is the same as EZNEC reports. If you don't like what EZNEC reports, take it up with Roy. As far as I can tell, Cecil has never been quite able to understand just what EZNEC reports. EZNEC doesn't need several different definitions of current to suit the theory du jour or to do its job, so it doesn't report "standing wave current" or other fruits of The Gifted One's overly fertile imagination. It simply reports current. Anyone not acquainted with this concept can refer to any basic text on electricity or physics. What EZNEC reports is exactly what you'll find there. Roy Lewallen, W7EL |
#6
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Roy Lewallen wrote:
Jim Kelley wrote: Cecil Moore wrote: . . The phase is referenced to the source phase, as it is in EZNEC, but you already knew that and just want to perform your usual diversions away from the technical facts. The current reported by EZNEC isn't referenced to source phase. The phases of all currents and voltages -- wire, source, and load -- are all referenced to the same arbitrary point. Source phase can be assigned by the user to any value relative to this point. The phase assigned by the user to the source obviously becomes the default reference phase. What on earth do you have to gain by obscuring that technical fact? If the user doesn't do anything, the source phase defaults to zero and all current measurements are referenced to that zero source phase. Are you so determined to discredit me that you are willing to sacrifice your integrity in the process? Do you deny that there is virtually no phase shift in the current up and down a 1/2WL dipole referenced to the source current. If you are up to that denial, please argue with Kraus's graphic. Take a look at the phase angles at: http://www.w5dxp.com/krausdip.jpg Unfortunately, Kraus agrees with EZNEC and that current is exactly what you used to make your meaningless measurements of current phase through a loading coil. So please look at Kraus's graph and tell us again how that current with unchanging phase can be used to measure phase shift through a loading coil. As far as I can tell, Cecil has never been quite able to understand just what EZNEC reports. EZNEC doesn't need several different definitions of current to suit the theory du jour or to do its job, so it doesn't report "standing wave current" or other fruits of The Gifted One's overly fertile imagination. It simply reports current. My point exactly! If the antenna being modeled is a standing-wave antenna, EZNEC reports standing-wave current. If the antenna being modeled is a traveling-wave antenna, EZNEC reports traveling-wave current. Roy apparently doesn't want anyone to know this fact. So Roy, why would the phase shift through a coil be different when it is used in a 1/2WL dipole vs using it in a rhombic at the same frequency??? Magic??? Roy has threatened to take EZNEC away from me for using it to demonstrate traveling-wave current through a loading coil. Here is what EZNEC says about the delay through that loading coil. http://www.w5dxp.com/coil512.ez Click on "Load Dat" and observe what Roy is so afraid that someone besides me is going to discover. -- 73, Cecil http://www.w5dxp.com |
#7
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Roy Lewallen wrote:
The current reported by EZNEC isn't referenced to source phase. If the source phase is set to zero and I want EZNEC to reference the antenna currents to 77 degrees, how would I go about that? -- 73, Cecil http://www.w5dxp.com |
#8
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On Mon, 17 Dec 2007 18:42:29 -0600, Cecil Moore
wrote: The phase assigned by the user to the source obviously becomes the default reference phase. On Tue, 18 Dec 2007 00:53:03 GMT, Cecil Moore wrote: If the source phase is set to zero and I want EZNEC to reference the antenna currents to 77 degrees, how would I go about that? Hmm, still confused about two different phases? In all of four lines you whip-saw from knowing it all to knowing nothing at all for what appears to be the same phase. At the fear of being presumptions, why don't you move the source 77 degrees along the radiator? Or insert a line 77 degrees long (which phase?). Or insert a lumped reactance that offers 77 degrees phase (which phase?). This is getting fun. Who woulda thunk? :-) |
#9
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On Mon, 17 Dec 2007 17:09:50 -0800, Richard Clark
wrote: On Mon, 17 Dec 2007 18:42:29 -0600, Cecil Moore wrote: On Tue, 18 Dec 2007 00:53:03 GMT, Cecil Moore wrote: I've just solved the phase duality problem!!!!!!!!! [observe above] Set your system clock to CST when you design the circuit/antenna/whatever and then reset your system clock to GMT before you press the Currents button. That should give you 90 degrees shift. Sorry, but this method only works in cardinal points of 15 degrees. Perhaps there is some neighboring county that uses Mars Twilight Savings Time for finer granularity. [These last two messages were performed as a public service to Roy, whose newsreader e-barfz in gag reflex to fuller quotations from Cecil.] 73's Richard Clark, KB7QHC |
#10
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Richard Clark wrote:
At the fear of being presumptions, why don't you move the source 77 degrees along the radiator? I don't think that will make Roy's statement true. Roy said: "The current reported by EZNEC isn't referenced to source phase." -- 73, Cecil http://www.w5dxp.com |
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