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Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Cecil Moore wrote: Jim Kelley wrote: 'Addition' is not a cause. Superposition is not a cause???? Superposition *IS* addition of phasors. Like addition, superposition is a mathematical operation. There is without question a mathematical result to most mathematical operations. But what does this operation itself actually cause in our case? A physical result has been obtained, but what is its exact cause? I don't think 'addition' is the best answer. 73, ac6xg |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Wed, 02 Jan 2008 16:23:02 -0800, Jim Kelley
wrote: I don't think 'addition' is the best answer. Hi Jim, Do you want an actual, legitimate answer guaranteed to end the quest, or are you having too much fun standing on Cecil's toes as he tries to tap dance? 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Jim Kelley wrote:
Cecil Moore wrote: Superposition *IS* addition of phasors. I don't think 'addition' is the best answer. Well, hang your favorite word on it. A rose by any other name ... -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Wed, 2 Jan 2008 22:47:27 -0500, "AI4QJ" wrote:
I have a piece of coax around here somewhere that I once burned up. BTW, in any case in which insulation melting occurs and we have deviated from the ideal transmission line, Ummm, Dan, as this is an explicitly new thread (purposely so to gouge this thumb into the ideal eye) with such an intro as you are responding to... We are not in Kansas any more. Jim's question is answered quite simply and you have offered one yourself, generously slathered with doubt about its obvious application. However, my guess finds the symptoms would be more aligned with two current nodes, not voltage. However, voltage or current, either mock the notion of "traveling waves," as Cecil recoils in shock from the bitter reality (his bête noire when it fails to serve his agenda) of this contradiction. It relates to another bitter round in his own thread of trying to explain the confusion Hams have with Rhombic antennas and traveling waves to then discover standing waves line up and down them: On Wed, 02 Jan 2008 21:19:53 GMT, Cecil Moore wrote: Ideal traveling-wave antennas have no standing waves. Formula: 1. The guru starts to resolve the confusion about real traveling wave antennas to the assembled unwashed masses; 2. a voice pipes up with simple data showing standing waves on real traveling wave antennas; 3. the guru abandons the explanation to resolve the confusion about real traveling wave antennas; 4. the guru denounces real traveling wave antennas as being non-ideal. I get a kick out of Cecil, really. The built in failures of his arguments are so scripted that mocking them is like writing for the sit-com where Dick Van Dyke forever trips over the ottoman. 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Richard Clark wrote:
Formula: 1. The guru starts to resolve the confusion about real traveling wave antennas to the assembled unwashed masses; 2. a voice pipes up with simple data showing standing waves on real traveling wave antennas; 3. the guru abandons the explanation to resolve the confusion about real traveling wave antennas; 4. the guru denounces real traveling wave antennas as being non-ideal. Anyone following this thread knows that the above is absolutely false. It is akin to dismissing lossless line analysis because lossless lines don't exist in reality. It is true that most real world standing wave antennas also possess traveling waves. When an antenna is 90% standing waves, the current on the antenna is primarily standing wave current with a phase that changes very little end to end. The traveling wave current is almost invisible. It is true that most real world traveling wave antennas also possess standing waves. When an antenna is 90% traveling waves, the current on the antenna is primarily traveling wave current with a phase that changes with length. The standing wave current is almost invisible. Richard is either very confused himself or deliberately trying to confuse others. Each reader can decide for him/herself. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Thu, 03 Jan 2008 16:34:25 GMT, Cecil Moore
wrote: Each reader can decide for him/herself. Shocking! Are you abdicating your role of Supreme Arbiter of Knowledge and leading Guru of RF? (I didn't see any white smoke coming out of the Vatican chimney to announce this portentous event.) Will there be a retirement party? |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Richard Clark wrote: On Wed, 02 Jan 2008 16:23:02 -0800, Jim Kelley wrote: I don't think 'addition' is the best answer. Hi Jim, Do you want an actual, legitimate answer guaranteed to end the quest, or are you having too much fun standing on Cecil's toes as he tries to tap dance? I was hoping to get Cecil to think a bit more carefully about what he has been saying. To provide quality, as well as quantity. 73, ac6xg |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Jim Kelley wrote:
I was hoping to get Cecil to think a bit more carefully about what he has been saying. To provide quality, as well as quantity. This newsgroup is not exactly an IEEE publication subject to peer review. Methinks you are asking too much for me to stop talking about phasor addition of two phasors. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Thu, 03 Jan 2008 11:24:28 -0800, Jim Kelley
wrote: I was hoping to get Cecil to think a bit more carefully about what he has been saying. To provide quality, as well as quantity. Aw, now you are shining us all on!! 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On 26 Dec 2007, 12:02, Jim Kelley wrote:
Cecil Moore wrote: What I said is the voltage and current in a standing wave are *always* 90 degrees out of phase and it is impossible to generate heat when the voltage and current are 90 degrees out of phase. So then shouldn't one expect coax to be heated uniformly along its length at a high SWR? 73, ac6xg Would it not be the current flowing on the outside copper of the coax fighting to transfer to ground while traveling to the transmitter ground as would happen if you chose the wrong antenna to transmit on? Art |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Thu, 3 Jan 2008 20:56:02 -0500, "AI4QJ" wrote:
Jim's question is answered quite simply and you have offered one yourself, generously slathered with doubt about its obvious application. However, my guess finds the symptoms would be more aligned with two current nodes, not voltage. However, voltage or current, either mock the notion of "traveling waves," as Cecil recoils in shock from the bitter reality (his bête noire when it fails to serve his agenda) of this contradiction. No it doesn't. As soon as heat is dissipated, then we know that there is a real power component where current is in phase with voltage. Hi Dan, That stands to reason. I think in this case the insulating material broke down due to high voltage. However, that does not. You (and I) don't have enough information (not that it matters in confounding Cecil). The reason is that, with an unterminated coax, the reflected wave adds to the forward wave only at those portions of the line where the standing wave was at maximum and minimum. This is rote (aside from the rough and loose description). If the linear amp had a forward component at Vmax = 6KV, then the standing wave maximum and minimum would be +12KV and -12KV. and this is the particular information neither of us has. How do you know Jim was running a linear, much less resulting with that particular voltage? The clipped voltage commentary is strictly conjecture. Your theory on the other hand, though possible, is lees likely in an amateur environment. The reason is that even a 22 AWG conductor can withstand a rather large amount of current before it gets so hot as to melt and damage the thermoplastic insulation. Fusing current for 22 AWG runs about 40A in ambient temperature. The inner core is not in ambient, but rather it is insulated (as you well testify), which lowers the current required to open it. We don't need fusing current but it does establish a rather dramatic caloric upper limit that easily exceeds the capacity of plastic to sustain exposure to the obvious heat. It is enough to say that lower currents could easily melt the plastic without having to "blow the fuse" so-to-speak. All that remains is additional information from Jim as to the physical clues of melting or carbonization. With thermal runaway a distinct probability, both probably occurred and it is then a chicken and egg problem. The wavelength distance of these burns from the open end will nail it down with far more assurance than anecdotal evidence. It relates to another bitter round in his own thread of trying to explain the confusion Hams have with Rhombic antennas and traveling waves to then discover standing waves line up and down them: In any antenna, you will have a combination of standing waves and traveling waves. It took me only one post to prove that with data. I am not responsible for Cecil's framing of the argument to the contrary. Most of Cecil's craft projects contain critical errors that collapse his argument into wandering statements. To this point of 400 postings, or so, absolutely no one has expressed any confusion that Cecil implied was his premise to explain in the original thread. His straw man kneed him in the groin before he could get in his first argument and the gasps of incredulity were his own. :-) What I was saying was, in the above example, even if you started out with an open coax line and a perfect standing wave where no real power was dissipated, immediately after the insulation broke dow real power started dissipating and that component could only be composed of travelling waves, in phase with current and voltage. It isn't that difficult, complex, or messy. All of this embroidery is like a traffic cop stopping you for speeding, and citing your violation in terms of galactic spin (tracking you at an even speed is vastly simpler and both you and the judge would be forced to agree that, yes, you were speeding). 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Richard Clark wrote:
"AI4QJ" wrote: In any antenna, you will have a combination of standing waves and traveling waves. It took me only one post to prove that with data. I am not responsible for Cecil's framing of the argument to the contrary. I fail to see what Richard thinks he has proven except that he disagrees with Balanis, Kraus, and Jasik. It is obvious that a lot of people don't understand the considerable difference between standing waves and traveling waves on an antenna or on transmission lines. Although every real-world antenna contains both standing waves and traveling waves, a 1/2WL dipole is classified as a standing-wave antenna and a terminated rhombic is classified as a traveling-wave antenna. Anyone who is interested can model those two antennas using EZNEC to observe the considerable difference in the antenna currents. Balanis dedicates most of "Antenna Theory", Chapter 10, Traveling Wave and Broadband Antennas", page 488, 2nd edition, to traveling-wave antennas like the terminated Beverage and rhombic. Also from "Antennas" by Kraus & Marhefka, 3rd edition: "The condition of a uniform traveling wave on an antenna is one of considerable importance, as this condition may be approximated in a number of antennas systems." He talks about terminated Beverage and rhombic antennas as examples of traveling-wave antennas. Jasik says: "Practically all standing-wave long-wire antennas have gone out of use with preference for the traveling-wave types." He then discusses the terminated rhombic as an example of a traveling-wave antenna. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
AI4QJ wrote:
I think in this case the insulating material broke down due to high voltage. J. C. Slater agrees with you. In "Microwave Transmission", he wrote: "Particularly in coaxial lines, the limit to the possible transmitted power is generally set by difficulties of corona or sparking between the two conductors of the line. The greatest practical reason for avoiding reflections is to reduce the magnitude of these voltage maxima." -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
Cecil Moore wrote:
Richard Clark wrote: "AI4QJ" wrote: In any antenna, you will have a combination of standing waves and traveling waves. It took me only one post to prove that with data. I am not responsible for Cecil's framing of the argument to the contrary. From The IEEE Dictionary: "traveling-wave antenna - An antenna whose excitation has a quasi-uniform progressive phase, as the result of a single feeding wave traversing its length in one direction only." Here are some more quotes from The ARRL Antenna Book: "All the antenna systems considered so far in this chapter have been based on operation with standing waves of current and voltage along the wire. ..." It then describes the concept of a terminated antenna and says: "In such an antenna there are no standing waves, because all received power is absorbed at either end." The terminated rhombic antenna is then described. About Beverage antennas: "Because the Beverage is a traveling wave, terminated antenna, it has no standing waves resulting from radio signals." -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a WARNING!!!
On Jan 2, 7:47*pm, "AI4QJ" wrote:
"Roy Lewallen" wrote in message ... Jim Kelley wrote: I have a piece of coax around here somewhere that I once burned up. *I recall telling you about it. *The insulation is bubbled and melted at half wavelength intervals. *Please explain what particular aspect of a traveling wave might have caused that to happen. It's the consequence of having *two* traveling waves, which occurs any time the line isn't terminated with its characteristic impedance. Betcha yours wasn't. As you have stated before, the standing wave is the ENVELOPE of maxima resulting from forward and reflected waves. The ENVELOPE maxima and minima will occur at 1/2WL distances in the cable. If the line is lossless, no power is consumed in the unterminated line. If *I were to see a cable with melted insultion at 1/2 wavelengths and the coax was open, the first thing I would suspect is that the voltage on the inner conductor greatly exceed the dilectric strength of the insulation between inner conductor and shield at the original standing wave maxima and minima. Two 3-500Z's in series could produce 6KV or even more. Standard Radio Shack grade RG58 might not be able to handle that. When the insulation breaks down it turns into a carbon resistor and we no longer have a lossless situation; real power is dissipated. Whther or ot the standing wave is still present, power will dissipate where the dielctric material has turned into carbon (even with DC). Less likely would be current heating the inner conductor, again a resistive power loss. But these discussions have been assuming a lossless line of infinite dielectric strength where real power disspiation cannot occur unless we terminate the line and only then, in the terminating component since the line is supposedly 'lossless'. Adding the real life burnt coax example when the discussion assumes ideal components is comparimg apples and oranges; all we are doing is exposing the weakness of the assumption when using ideal lossless components. BTW, in any case in which insulation melting occurs and we have deviated from the ideal transmission line, at least some of the reactive power that was contained in the standing wave has now been changed into a travelling wave with I/V in phase thru the 'resistors' between inner conductor and shield. This is the discussion I was hoping Cecil would take up. I can assure you that the coax I was using was not lossless; RG58 is quite real in that respect. The source was probably good for a kilowatt at 2.4 GHz, though it's likely only a small fraction of that was actually coupled from the cavity by Langmuir probe into a 50 ohm termination of some sort. (This was 20 years ago, so some of the details have faded now.) The cable got hotter than a firecracker in a very short period of time over centimeter sized regions spaced some number of centimeters apart. The coax appeared to have melted due to excessive I^2R heating by the conductors. Skin effect apparently played no small role. I believe the voltage in question is not the voltage across the dielectric, but rather along the conductor. At my suggestion the experiment was not repeated. :-) 73, ac6xg |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 00:40:23 -0600, Cecil Moore
wrote: Here are some more quotes Dragging more bones out of the crypt and calling them USDA Prime Rib. About Beverage antennas: "Because the Beverage is a traveling wave, terminated antenna, it has no standing waves resulting from radio signals." Well, that explains a Rhombic to clear up everyone's confusion! Gee, Mr. Peabody, let's step into the "Way-Back machine" and find us an example of this Beverage antenna! I suppose this example would be either too real, and unrepresentative of our Guru's pronouncements of RF purity; OR I suppose this example would be too text book, and unrepresentative of our Guru's pronouncements of RF reality. Gad, was is a loathsome degenerate like me suppose to do when faced with a dilemma like this? I mean, damned if you do one, and damned if you do the other. The only choice is to use one of Cecil's designs and see what Cecil would pop an aorta over. So, with that in mind, I simply step into the Way-Back machine and crank in Tue, 18 Dec 2007 09:33:23 -0600, Cecil Moore wrote: The traveling-wave file is: http://www.w5dxp.com/TravWave.EZ It has already been demonstrated that it is inferior in design, but in full faith to the original designer's intent of exhibiting a traveling wave, I must stoop to accept less for the sake of embracing its lineage (shudder). Dear readers, we must take care not to upset the harmony of the crystal spheres of our esteemed Guru of the Airwaves; however, fashion dictates that the most recent withdrawal from the vaults above demand an external radio signal, not one driving his divine inspiration. As always, the best way to confound Cecil is to embrace his own work. So, by the simple addition of ONE WIRE, 60 feet tall and located 100,000 feet away (we can't be bothered with interactions polluting this study) we then shift the source to this distant radio to see what currents are pressed upon the receiving antenna (as is such the obvious destiny of the Beverage). SWR along the length of the line: 8:1 Hmm, must be the charm of the original designer that so pollutes those ancient tomes exposed to the cold cathode light of the Xerox. This shocking result is certainly not the product of original thinking. At this juncture, dare I attempt something more conventional? After all, the Beverage is classically taller than Cecil's one foot tall munchkin. It also resides over real ground, which, after all, is the classic ingredient to its success. Having embraced damnation in using Cecil's I can't be burned in purgatory for any more normal design. So, let's see what appears on the radio from designs that are more classic. This time we have a 1000 meter long wire 3 meters above ground; 100,000 meters away is our transmitter; we are operating on 3.8MHz; the load of 600 Ohms is placed against a radial system below it; there are 16 radials, each only 4 meters long, 1 centimeter above real, high accuracy ground. We turn on the transmitter, and look at the SWR due to currents reported: 8:1 SWR at the transmitter end with the current phase swinging like a pendulum. With something like 300 segments, that is roughly a 18 degree shift per segment along the wire (Cecil's forecast was 0) over a continuum of 360 degrees (cycle repeats every 20 segments like clock work). No doubt this unfortunate pair of designs (the prince and the pauper) will evoke calumny and rage against this miserable churl for presuming to interpret the mystic arts known only to the Gurus. Another explanation might be that Traveling waves means something altogether different than how they are commonly discussed on this board. Perhaps the Xerox will reveal that nuance. Maybe it is a threshold issue. The Guru need only climb the mount for more tablets of scripture to render: "All SWR less than 2:1 is henceforth decreed by holy writ to be flat and conforming to the ecumenical standards of Traveling Waves - so has it been said, so shall it ever be!" 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
http://www.w5dxp.com/TravWave.EZ It has already been demonstrated that it is inferior in design, It is not an antenna - it is a wire that demonstrates traveling waves by eliminating reflections. We turn on the transmitter, and look at the SWR due to currents reported: 8:1 SWR at the transmitter end with the current phase swinging like a pendulum. With something like 300 segments, that is roughly a 18 degree shift per segment along the wire (Cecil's forecast was 0) Sorry, Richard, that is a false statement. With traveling wave antennas, there is a phase shift per segment. An antenna with an SWR of 8:1 is neither a traveling-wave nor a standing-wave antenna but is a hybrid between the two. As usual, you have either confused yourself or are trying to confuse others. Sometimes it is hard to tell which. A 1/2WL dipole is a standing-wave antenna with an SWR ~20:1 on the antenna wire. Take a look at its current phase. A traveling-wave antenna needs an SWR close to ~1:1 to be a good example. Whether by accident or on purpose, yours is a very poor example. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 13:59:55 GMT, Cecil Moore
wrote: A 1/2WL dipole is a standing-wave antenna with an SWR ~20:1 on the antenna wire. Now there's an original observation. A traveling-wave antenna needs an SWR close to ~1:1 to be a good example. Whether by accident or on purpose, yours is a very poor example. I used your Traveling Wave antenna. :- We can both agree the data reveals the truth of it being a very poor example. Dear Readers. This was another slam-dunk. It was easier than collecting unemployment. The simplest part is using Cecil's own examples and drilling into their fault seams. Like this one, they usually split open and spill their contents like an overripe watermelon. It is unlikely that any better example will arrive that bears any resemblance to what Beverage designed, so the data once again goes undisputed in confounding the Guru of the Airwaves. |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
A traveling-wave antenna needs an SWR close to ~1:1 to be a good example. Whether by accident or on purpose, yours is a very poor example. I used your Traveling Wave antenna. :- http://www.w5dxp.com/TravWave.EZ Good grief, Richard! You cannot use the 8.4:1 50 ohm SWR reading for the SWR on a wire with a characteristic impedance of 411 ohms. I see what you did now and it is was more than stupid. The load resistor is 411 ohms. The characteristic impedance of the wire is close to 411 ohms. Set the Alt SWR Z0 to 411 ohms and observe the actual SWR of 1.025:1. The SWR is 1.025:1. The current on the wire is close to 100% traveling wave current. You observed the phase shift and reported it. You have proved my point while trying to discredit it. Thank you very much. The reason that I didn't defend myself against what you were saying is that I didn't believe anyone would be so stupid as to report the 50 ohm SWR on a wire with a characteristic impedance of 411 ohms. Therefore, I didn't know you were talking about my example. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 10:55:37 -0600, Cecil Moore
wrote: Richard Clark wrote: A traveling-wave antenna needs an SWR close to ~1:1 to be a good example. Whether by accident or on purpose, yours is a very poor example. I used your Traveling Wave antenna. :- http://www.w5dxp.com/TravWave.EZ Good grief, Richard! You cannot use the 8.4:1 50 ohm SWR reading for the SWR on a wire with a characteristic impedance of 411 ohms. I see what you did now and it is was more than stupid. The load resistor is 411 ohms. So it was, so it is, and so shall it always be to demonstrate a dramatic variation of CURRENT. All rather standard stuff. The SWR report from EZNEC is source based, and that source was 100km distant from the RECEIVE antenna - wholly remote from my care and consideration. I didn't make your mistake, you made it alone for yourself. Mount it like a trophy on your mantle with the rest. With great misfortune, TravWave.EZ is, as you say, an atrocious antenna, and nothing like what Beverage designed which my second example more clearly reveals. I simply used your poor antenna so as to increase the likelihood of its impeachment by its designer. This, of course, triggered the script where that author condemned his own creation; and all the choreographed marks were hit precisely as anticipated. Dear readers, With such limp struggles as offered by Cecil, this has long passed the point of being a challenge. It rarely takes much effort to crack his arguments open, but having done it several times here alone, it can only be described as a Sado-Masochistic spectacle. My arm is getting tired with swinging the whip and Cecil's groans have long since lost their siren call. Perhaps some future outrage from Cecil will invigorate the song of the lash. When dawn breaks, it will no doubt reveal TravWave.EZ disowned and cast out of the home as a fraud. I will undoubtedly be described as its immoral progenitor because TravWave.EZ is so obviously the spawn of a demented troglodyte slipped into Cecil's nest like a cuckoo's egg. 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves, and other stupid notions
Cecil Moore wrote:
There is zero real power in standing waves. The sentence is true, and is without need of the words 'real' and 'standing' to make it so. Therefore, standing waves did not destroy the coax. :-) Yes and no. Were it not for waves standing on the coax, there would have been no damage to the coax, and there wouldn't be an explanation for the damage pattern. So your 'truism' has some significant caveats. I guess that makes it more of a ....'half-truism'. By the process of elimination, it was traveling waves that destroyed the coax. Kinda tough to have a standing wave in the absence of traveling waves now, isn't it. During the initial transient state, traveling wave energy becomes standing wave energy that exists through steady-state. So there's energy in the standing waves, but not power. Apparently they're like traveling waves......that stand! Probably best not to assume it's a 'different kind of wave' in the first place. Maybe it would be better just to think of it as a pattern formed by traveling waves - an appearance that traveling waves can have under certain circumstances which produces stationary effects. Yes I know that's basically what you've been trying to say "all along", but you were saying it so poorly that it was indistinguishable from fantasy. J. C. Slater says it is more likely that the damage occurred at the current nodes rather than at the voltage nodes. I didn't even know he was there! But it is consistent with what J.W. Kelley has said about it. :-) 73, ac6xg |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
I haven't been following this particular discussion of "standing wave
antennas" vs "traveling wave antennas" because it looks to me like just another diversion to avoid confronting the sticky problems with alternative theories, and one that's been used and discussed many times before. But I see that EZNEC's report of SWR has been mentioned, so I'd like to make sure that readers understand what it means. EZNEC reports an "SWR" for each source, and will also plot this as a function of frequency. This is *not* the SWR on an antenna (assuming that you can even rigorously define it), nor is it necessarily the SWR on a transmission line to which the source is connected, if it is connected to a line. It's only an alternate way of describing the impedance seen by the source, just like your transmitter's SWR meter. The reported SWR is the the SWR which would exist on a 50 ohm transmission line if that transmission line were connected between the source and its load, whether one is or not. It shows the same value as your transmitter SWR meter would if you replaced the source with your transmitter. An alternate SWR Z0 value can be specified so you can also see what the SWR would be on a transmission line of some other impedance. It's not necessary, or even likely, that there will be a transmission line or even wire (again, if you can even define SWR for a single conductor) which actually has an SWR equal to the value reported by EZNEC. If you were to connect your transmitter to a 50 ohm load through a half wavelength 300 ohm transmission line, the SWR on the transmission line would be 6:1, but your rig's SWR meter would read 1:1. If you modeled this with EZNEC, it would show the 50 ohm SWR as 1:1 (like your transmitter SWR meter). If you set the alternate SWR Z0 to 300 ohms, it would correctly show the 300 ohm SWR to be 6:1. If you connected your transmitter directly to a 150 ohm resistor, your rig's SWR meter (and EZNEC's 50 ohm SWR) would read 3:1, even though there is no transmission line of any impedance and therefore no standing waves anywhere. Roy Lewallen, W7EL Richard Clark wrote: On Fri, 04 Jan 2008 10:55:37 -0600, Cecil Moore wrote: Richard Clark wrote: A traveling-wave antenna needs an SWR close to ~1:1 to be a good example. Whether by accident or on purpose, yours is a very poor example. I used your Traveling Wave antenna. :- http://www.w5dxp.com/TravWave.EZ Good grief, Richard! You cannot use the 8.4:1 50 ohm SWR reading for the SWR on a wire with a characteristic impedance of 411 ohms. I see what you did now and it is was more than stupid. The load resistor is 411 ohms. So it was, so it is, and so shall it always be to demonstrate a dramatic variation of CURRENT. All rather standard stuff. The SWR report from EZNEC is source based, and that source was 100km distant from the RECEIVE antenna - wholly remote from my care and consideration. I didn't make your mistake, you made it alone for yourself. Mount it like a trophy on your mantle with the rest. With great misfortune, TravWave.EZ is, as you say, an atrocious antenna, and nothing like what Beverage designed which my second example more clearly reveals. I simply used your poor antenna so as to increase the likelihood of its impeachment by its designer. This, of course, triggered the script where that author condemned his own creation; and all the choreographed marks were hit precisely as anticipated. Dear readers, With such limp struggles as offered by Cecil, this has long passed the point of being a challenge. It rarely takes much effort to crack his arguments open, but having done it several times here alone, it can only be described as a Sado-Masochistic spectacle. My arm is getting tired with swinging the whip and Cecil's groans have long since lost their siren call. Perhaps some future outrage from Cecil will invigorate the song of the lash. When dawn breaks, it will no doubt reveal TravWave.EZ disowned and cast out of the home as a fraud. I will undoubtedly be described as its immoral progenitor because TravWave.EZ is so obviously the spawn of a demented troglodyte slipped into Cecil's nest like a cuckoo's egg. 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
Cecil Moore wrote: The load resistor is 411 ohms. So it was, so it is, and so shall it always be to demonstrate a dramatic variation of CURRENT. All rather standard stuff. The SWR report from EZNEC is source based, ... That's your stupid mistake. The SWR on the wire is load- based and is equal to 1.025:1, close enough to call that wire a traveling-wave configuration. If you are so stupid that you don't even recognize your stupid mistake, I don't think anything can be done for you. The load is 411 ohms. The Z0 of the wire is close to 411 ohms. The SWR on the wire is close to 1:1. It is a traveling wave configuration essentially devoid of standing waves. The traveling wave current pattern is obvious. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 11:33:28 -0800, Roy Lewallen
wrote: But I see that EZNEC's report of SWR has been mentioned, so I'd like to make sure that readers understand what it means. Hi Roy, Cecil simply presumed (without reading the antenna specification, nor trusting his own design) that my report of SWR was based on a source exciting the line. First, and evidence of his poor reading skills, I specified that I had constructed a remote transmitter antenna to excite the test antenna (there were two). As you offer in unquoted material, the SWR report would have related to that source, in its own environment. I was wholly unconcerned with that, specifically. All SWR determinations followed the rather more prosaic method of simply observing current magnitudes along the length of the line, much like my work at the bench when I made similar measurements with similar techniques traceable to NBS. Second, and with attention to his own reference citation that a Beverage antenna "...has no standing waves resulting from radio signals;" I introduced this remote excitation to provide just that: "radio signals" and not transmit excitation. Obviously, Cecil spends more time Xeroxing authorities than reading them. So, the net effect is I used his model, and his referenced authority, pulled them together into a simple test which shows that, yes, standing waves inhabit the length of HIS traveling wave antenna when it is excited externally (as it must to conform to his authority). As Cecil has condemned his own design, I then also repeated this exercise with a design that more faithfully follows Beverage's design principles. Rather simple stuff. 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves, and other stupid notions
Jim Kelley wrote:
Were it not for waves standing on the coax, there would have been no damage to the coax, ... Were it not for traveling waves, there would be no standing waves and no damage to the coax. Kinda tough to have a standing wave in the absence of traveling waves now, isn't it. Exactly, but that supports my side of the argument. So there's energy in the standing waves, but not power. At the risk of you developing apoplexy, there is reactive power in the standing waves, as defined in The IEEE Dictionary. Probably best not to assume it's a 'different kind of wave' in the first place. Sorry Jim, but [Io*cos(kx)*cos(wt)] and [Io*cos(kx+wt)] *ARE* different. If you don't know enough math to realize that by looking at the equations, please go alleviate your ignorance. Yes I know that's basically what you've been trying to say "all along", but you were saying it so poorly ... Sorry, my native tongue is Texan. :-) -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Roy Lewallen wrote:
I haven't been following this particular discussion of "standing wave antennas" vs "traveling wave antennas" ... It certainly has a bearing on whether standing wave current can be used to determine the delay through a 75m loading coil like you have said it can. Please take a look at the current phase reported by EZNEC and tell us once again how an constant phase at all points on the antenna at any particular time can be used to measure delay through the wire. This is *not* the SWR on an antenna ... An alternate SWR Z0 value can be specified so you can also see what the SWR would be on a transmission line of some other impedance. Richard C., are you reading this straight from the horse's mouth? -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 20:03:04 GMT, Cecil Moore
wrote: The SWR on the wire is load- based and is equal to 8:1 as evidenced by CURRENT on the wire. :-) You cannot make a SWR measurement on a receive antenna any other way. |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
So, the net effect is I used his model, and his referenced authority, pulled them together into a simple test which shows that, yes, standing waves inhabit the length of HIS traveling wave antenna when it is excited externally (as it must to conform to his authority). As Cecil has condemned his own design, I then also repeated this exercise with a design that more faithfully follows Beverage's design principles. I didn't even look at what you were doing but you were *NOT* using my model so please quit fibbing about it. If you are going to excite my example remotely, you need a 411 ohm load resistor on each end of the wire. I assume you are ignorant of that fact of physics. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
On Fri, 04 Jan 2008 20:03:04 GMT, Cecil Moore wrote: The SWR on the wire is load- based and is equal to 8:1 as evidenced by CURRENT on the wire. :-) You cannot make a SWR measurement on a receive antenna any other way. My TravWave.EZ file doesn't have a receive antenna so your comment is irrelevant. By your way of thinking, The SWR on the transmit antenna has to be the same as the SWR on the receive antenna. I have rarely ever heard such absolute cagada. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves, and other stupid notions
Cecil Moore wrote:
Sorry Jim, but [Io*cos(kx)*cos(wt)] and [Io*cos(kx+wt)] *ARE* different. Evidently, you can't recognize a trig identity when you see one. If you don't know enough math to realize that by looking at the equations, please go alleviate your ignorance. Sorry, my native tongue is Texan. :-) Your tongue may be Texan, but the rest of you is pure arsehole. :-) ac6xg |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Fri, 04 Jan 2008 14:31:33 -0600, Cecil Moore
wrote: If you are going to excite my example remotely, you need a 411 ohm load resistor on each end of the wire. :-O There IS a Santa Claus! Thank you, Thank you, Thank YOU! I did that too!!!! SWR = 29:1 Dear Readers, The snap of the whip sings holiday carols when you hold back your trump cards. A late present, and a most wonderful one. ;-) |
Standing morphing to travelling waves, and other stupid notions
Jim Kelley wrote:
Cecil Moore wrote: Sorry Jim, but [Io*cos(kx)*cos(wt)] and [Io*cos(kx+wt)] *ARE* different. Evidently, you can't recognize a trig identity when you see one. Good grief, Jim, please solve the following "identity". cos(kx)*cos(wt) = cos(kx+wt) Find all (x,t) for which that equation is true. I'm expecting an "attitude adjustment" from you. Everyone is invited to solve the above equation for (x,t). Hint: I solved it a long time ago. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
Cecil Moore wrote: If you are going to excite my example remotely, you need a 411 ohm load resistor on each end of the wire. SWR = 29:1 You are mistaken or bearing false witness - neither of which is a plus for you. -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves, and other stupid notions
"Jim Kelley" wrote in message ... Cecil Moore wrote: Sorry Jim, but [Io*cos(kx)*cos(wt)] and [Io*cos(kx+wt)] *ARE* different. Evidently, you can't recognize a trig identity when you see one. in my book cos(a+b)=cos(a)cos(b)-sin(a)sin(b) so cos(kx+wt) would expand to: cos(kx)cos(wt)-sin(kx)sin(wt) me thinks you are missing a few terms in your 'identity'. |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
Richard Clark wrote:
SWR = 29:1 Richard, to prove that you are not 100% insane, would yo please attempt to prove that the SWR in the transmit antenna is in any way related to the SWR in the receive antenna? -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves, and other stupid notions
Dave wrote: "Jim Kelley" wrote in message ... Cecil Moore wrote: Sorry Jim, but [Io*cos(kx)*cos(wt)] and [Io*cos(kx+wt)] *ARE* different. Evidently, you can't recognize a trig identity when you see one. in my book cos(a+b)=cos(a)cos(b)-sin(a)sin(b) so cos(kx+wt) would expand to: cos(kx)cos(wt)-sin(kx)sin(wt) me thinks you are missing a few terms in your 'identity'. I'm sure your book is correct, Dave. Mine probably is too. (It has CRC Standard Mathematical Tables printed on the cover.) Cecil through a curve ball. The correct function for a standing wave can be written as the algebraic sum of two sine functions, or as the product of a sine and a cosine function e.g. y = 2*Ymax*sin(kx)cos(wt). 73, ac6xg |
Standing morphing to travelling waves, and other stupid notions
Jim Kelley wrote:
I'm sure your book is correct, Dave. Mine probably is too. (It has CRC Standard Mathematical Tables printed on the cover.) Cecil through a curve ball. The correct function for a standing wave can be written as the algebraic sum of two sine functions, or as the product of a sine and a cosine function e.g. y = 2*Ymax*sin(kx)cos(wt). I'm surprised that a physics professor doesn't recognize the difference between the conventions of RF engineering and optical physics (which are essentially meaningless). Is discrediting me really worth denying the laws of physics? -- 73, Cecil http://www.w5dxp.com |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
On Sun, 6 Jan 2008 17:37:37 -0500, "AI4QJ" wrote:
"Richard Clark" wrote in message .. . On Fri, 04 Jan 2008 20:03:04 GMT, Cecil Moore wrote: The SWR on the wire is load- based and is equal to 8:1 as evidenced by CURRENT on the wire. :-) You cannot make a SWR measurement on a receive antenna any other way. You are making a "Voltage" standing wave measurement based ion the CURRENT of the wire? Hi Dan, I don't know about ions; but, sure, voltage standing wave measurement is as accurate as current standing wave measurement. Or perhaps you need to make your question a little more terse (don't rely on the continuity of discussion involving Cecil's quotes to fully inform any argument). In other words, filter out the static and frame your own question. 73's Richard Clark, KB7QHC |
Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
"AI4QJ" wrote in message ... "Richard Clark" wrote in message ... On Fri, 04 Jan 2008 20:03:04 GMT, Cecil Moore wrote: The SWR on the wire is load- based and is equal to 8:1 as evidenced by CURRENT on the wire. :-) You cannot make a SWR measurement on a receive antenna any other way. You are making a "Voltage" standing wave measurement based ion the CURRENT of the wire? AI4QJ sure, VSWR is just as valid as Current-SWR, they are absolutely identical... the only difference is that VSWR is the amateur 'standard' because it was frequently easier to measure the voltage than the current... i.e. on open wire feeders all you had to do was run a neon bulb or other cheap voltmeter along the line to find the min and max voltage points... for a current measurement you would have to couple a loop around the line or insert shunts, not nearly as simple as measuring a voltage... so vswr was the 'standard'... though just plain swr, refering to either one, is just as proper. |
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