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Cecil Moore wrote: Jim Kelley wrote: You do understand what a standing wave pattern is, right? At any instant of time at a standing wave current maximum point (loop, antinode), the charge carriers are either moving toward the load (ends of the dipole) or toward the source (feedpoint). You do understant that a standing wave pattern is NOT a plot of instantaneous voltages or currents, right? 73, Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: Current cannot stand still. You keep saying that as if it was relevant. It is relevant to the logical corner into which you have painted yourself. There exists current at the base of a coil. It either flows into the coil or away from the coil. There is simply no other place for it to go since it cannot stand still. Both in to and out of. Not one or the other. You are forgetting your conventions. If the current at the bottom of the coil is in phase with the feedpoint current, it is flowing the same direction as the feedpoint current. By convention, the feedpoint current is assumed to be flowing *into* the antenna. Therefore, by convention, the in-phase current at the bottom of the coil is assumed to be flowing *into* the coil referenced to the feedpoint current. EZNEC references all currents to the feedpoint current which (surprise!) is feeding, i.e. flowing into the antenna. If the current at the bottom of the coil is out of phase with the feedpoint current, by convention, the current is flowing in the opposite direction to the feedpoint current, i.e. out of the coil. What you say is irrelevant to the established conventions. What is a sophomoric notion is your notion that current doesn't flow when it's associated with a coil. I have no such notion. You can't have it both ways, Jim. Either current flows into a coil or it doesn't. I say it does for 1/2 cycle referenced to the source. You are arguing with me about that assertion. Then I observe that neither you nor Tom completely understands standing waves. I don't "completely understand" anything, Jim. It is delusional to believe that you are unique in completely understanding anything. May I remind you of something Einstein said: "One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike ..." The current in standing waves flows - it doesn't stand still. You have been seduced by your math model. Current can only stand if dQ/dt equals zero. Otherwise, it is flowing in one of two possible directions available in a wire. Your notion of current phase is literally a figment of your imaginary number imagination. All real-world non-zero current is real and, in a wire, flows in only one of two possible directions. By convention, that direction is the sign of the cosine term referenced to the source. The magnitude of the current is Imax*cos(x). The phase is always either zero or 180 degrees. There is absolutely no difference in 1a at 45 deg. and 0.707a at zero deg. The j0.707a doesn't exist in reality. -- 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! =----- |
Jim Kelley wrote:
Cecil Moore wrote: Yep, and for the same power level, a higher impedance usually means a lower current and vice versa. But the impedance *at* such points does not affect the current *at* those points? Cause and effect, Jim. Hint: The impedance equals v/i and is completely virtual, i.e. clearly a result, not a cause. Even the feedpoint impedance of an antenna is a ratio of v/i which is often simply the result of interference between forward and reflected waves. -- 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! =----- |
Cecil Moore wrote: There exists current at the base of a coil. It either flows into the coil or away from the coil. If it is DC current, you're right. If it is AC, then you're talking about wave propagation. You're confusing the two things. You have to decide which one you want to talk about. Both in to and out of. Not one or the other. You are forgetting your conventions. If the current at the bottom of the coil is in phase with the feedpoint current, it is flowing the same direction as the feedpoint current. By convention, the feedpoint current is assumed to be flowing *into* the antenna. Therefore, by convention, the in-phase current at the bottom of the coil is assumed to be flowing *into* the coil referenced to the feedpoint current. EZNEC references all currents to the feedpoint current which (surprise!) is feeding, i.e. flowing into the antenna. If the current at the bottom of the coil is out of phase with the feedpoint current, by convention, the current is flowing in the opposite direction to the feedpoint current, i.e. out of the coil. What you say is irrelevant to the established conventions. Not at all. What I say is the way AC voltage and currents are summed. We don't talk about alternating current flowing in only one direction or another. That would be silly. It's something I've only seen you do. 73, Jim AC6XG |
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: Yep, and for the same power level, a higher impedance usually means a lower current and vice versa. But the impedance *at* such points does not affect the current *at* those points? Cause and effect, Jim. Hint: The impedance equals v/i and is completely virtual, i.e. clearly a result, not a cause. Little v over little i, Cecil? Are we talking instantaneous impedances now also? ;-) 73, Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: At any instant of time at a standing wave current maximum point (loop, antinode), the charge carriers are either moving toward the load (ends of the dipole) or toward the source (feedpoint). You do understand that a standing wave pattern is NOT a plot of instantaneous voltages or currents, right? It is whatever you define it to be, Jim. You cannot display a real- time plot on a piece of paper. The standing wave patterns in The ARRL Antenna Book are RMS patterns. I have also seen them plotted as envelope patterns which is, IMO, a better representation. Whatever is plotted on a sheet of paper is some sort of time-frozen snapshot, by definition. EZNEC can display the relative phase of standing wave current, or not, depending upon what you want. -- 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! =----- |
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: At any instant of time at a standing wave current maximum point (loop, antinode), the charge carriers are either moving toward the load (ends of the dipole) or toward the source (feedpoint). You do understand that a standing wave pattern is NOT a plot of instantaneous voltages or currents, right? It is whatever you define it to be, Jim. If that's what you think, then the answer is you don't know what a standing wave pattern is, and there really is nothing further I can discuss with you on the subject. Good luck, and have fun in the contest OM. 73 de AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: There exists current at the base of a coil. It either flows into the coil or away from the coil. If it is DC current, you're right. If it is AC, then you're talking about wave propagation. You're confusing the two things. You have to decide which one you want to talk about. Nope, it is you who are confusing waves (photons) with current (dQ/dt). I have said nothing about photon waves. Everything I have said applies to current, i.e. dQ/dt where the charge carriers are electrons and reverse direction every 1/2 cycle. That the electrons launch photons in waves is irrelevant to this current discussion. dQ/dt (current) doesn't change much because of photon acquisition or loss. We don't talk about alternating current flowing in only one direction or another. Of course we do, Jim. We talk about the AC generator source current flowing from the power stations to our houses. In general, AC current flowing in phase with the generator current is considered to be flowing away from the generator toward the load, by convention. This is clearly illustrated in my college textbooks where AC RMS values replace DC values. -- 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! =----- |
Jim Kelley wrote:
Cecil Moore wrote: Cause and effect, Jim. Hint: The impedance equals v/i and is completely virtual, i.e. clearly a result, not a cause. Little v over little i, Cecil? Are we talking instantaneous impedances now also? ;-) Give me a break, Jim. I'm reading a book titled, "The Matter Myth", so my mind is blown and you are mostly empty space. :-) -- 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! =----- |
Jim, as I read the arguement, (and these guys are RIGHT), you are confusing
current being constant, in a media, with POWER being constant in a media (minus insertion loss's, of corse). for example, visualize a 1/4 wave (or a 1/2 wave dipole) , at the feedpoint, what is the current? even at a 1:1 swr, in coax, the current is constant, as you predict! But, WHAT, PREY, is the current, at the far END (S) of that 1/4 wave (DIPOLE) ? answer is 0 ! but the voltage has increased to that necessary to equal the amount of power impressed on it (I realize that any number times, 0 = 0, but, obviously, there is a physical limit approaching this, and also, for the power to stay the same, you would have an INFINANT voltage!! This is the stuff that R.F. BURNS are made of! And, when SWR is measured in a cable, current (and voltage) will vary, depending upon WHERE , in the cable that you measure current, (or voltage, even tho, the POWER must stay the same, again considering losses in the transmission line: As information, another Jim, NN7K -- No trees were killed in the sending of this message. However, a large number of electrons were terribly inconvenienced "Jim Kelley" wrote in message ... Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: Yep, and for the same power level, a higher impedance usually means a lower current and vice versa. But the impedance *at* such points does not affect the current *at* those points? Cause and effect, Jim. Hint: The impedance equals v/i and is completely virtual, i.e. clearly a result, not a cause. Little v over little i, Cecil? Are we talking instantaneous impedances now also? ;-) 73, Jim AC6XG |
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