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Richard Harrison wrote: Cecil, W5DXP wrote: "That`s where you are wrong." This argument has evoked plain statements, i.e., "When waves cease to exist, they are forced to give up their intrinsic energy." And, "Waves don`t cease to exist." The statements need qualifications. Perhaps waves "cancel" without ceasing to exist. In the case we've been discussing the waves in fact never exist, except on paper. This is because, for example, V3 and V4 cancel at the very point at which they would begin to propagate. Cancellation precludes their existance because they cancel for any time element (after the transient period) and for every spacial element one can enter into the equation. Contrary to what has been suggested, they do not first appear and then subsequently disappear. Waves cannot just "cease to exist" for the very same reason that energy cannot cease to exist. It may be somewhat easier to see this when we consider that each boundary can be viewed as a radiator, or re-radiator. When a wave impinges upon it, the boundary conditions and the nature of the incident wave determine how waves will be re-radiated from it. With a wave impinging upon the boundary from one direction only, we would have one outcome. With two or more waves impinging upon the boundary, we may have a different outcome. 73, Jim AC6XG |
Jim Kelley wrote:
Waves cannot just "cease to exist" for the very same reason that energy cannot cease to exist. More bafflegab. An RF wave ceases to exist when it is dissipated in a dummy load. The energy cannot cease to exist and turns to heat but the RF wave, in a perfect dummy load, ceases to exist. Heat is not RF. A light wave incident upon a perfect flat black plane ceases to exist. The light waves that haven't exited the room you are in when you turn off the light cease to exist. Some light waves falling upon plants cease to exist in the process of photosynthesis. From _Optics_, by Hecht: "Unlike ordinary objects, photons cannot be seen directly; what is known of them comes from observing the results of their being either created or annihilated." When photons are created, their wave function starts. When photons are annihilated, their wave function ceases to exist. There is no such thing as preservation of photons. You really need to get yourself a better physics book. EM waves cease to exist all the time but the energy in those waves cannot be destroyed. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
Yeah, you've got me pegged, all right -- tireless defender of ham
radio's sacred cows. Perceptive of you. But we can all be thankful we've got you to keep reminding us hams just how ignorant we, worshipping our superstitious lore, are, compared to true professionals like you. If only we could just come up an impedor for this. Roy Lewallen, W7EL W5DXP wrote: Dave Shrader wrote: Roy, you've been getting blamed for everything lately. Now we can blame you for the new thread ... you started it! grin Roy doesn't seem to appreciate me making hamburger out of ham radio's sacred cows. :-) I actually enjoy the T-Bones best of all. |
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I hope you'll pardon me for amplifying this a little.
If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL Dr. Slick wrote: (Art Unwin KB9MZ) wrote in message m... 1. Two antennas (also called transducers) placed close together actually can be considered a transformer, albeit a very inefficient one. Humm...By antenna I assume it also means a radiator. This would suggest that a stagger tuned radiators would fall into the catagory discussed above. Now I have a problem with that statement, because I very much see it as a transformer which is VERY efficient and not as you stated "albiet a very inefficient one". Can you explain to me how a stagger tuned antenna migrate into inefficient radiators? Seems to me that Thevenin's theorem would show this as being incorrect ! Well, two identical antennas spaced a few wavelengths apart can be considered a transformer, but very inefficient compared to a "real" transformer with identical primary and secondary turns, with an appropriate toroid core. This would be because the core material will increase the magnetic flux density, and will increase the coupling between the two windings/transducers. Point is, the farther apart the antennas are, the less efficient of a "transformer" they will be. I'm not familiar with stagger tuned antennas, although the name would suggest that it is tuned for multiple resonances, so that the antenna will be broadband. Slick |
Roy Lewallen wrote in message ...
I hope you'll pardon me for amplifying this a little. If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. Yes Roy. The specifics of what is being discussed is all important when looking at answers as well as what terms are being used to measure 'efficiency' and to what ends. As you are surely awawe I too look at antennas as transformers or coupled circuits and thus the primary contributes very much in its own way as far as radiation as does the secondary. Thus 'efficiency' as a criteria of 'value' is all important when using it as a term since as you point out it is a ratio of two terms both of which have to be made very clear for the term efficiency to be made clear Thus in stagger tuning it is important to define your requirements in terms of bandwidth (dual frequency radiation) or max gain ( dual radiators on the same frequency),the above bearing little difference to old time receiver designwith multiple I.F. cans. It is in this areana that I view stagger tuning or coupling as being efficient in charactor. If I am incorrect in the above assumptions I would welcome any correction from those well versed inthe field. Best regards Art If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL Dr. Slick wrote: (Art Unwin KB9MZ) wrote in message m... 1. Two antennas (also called transducers) placed close together actually can be considered a transformer, albeit a very inefficient one. Humm...By antenna I assume it also means a radiator. This would suggest that a stagger tuned radiators would fall into the catagory discussed above. Now I have a problem with that statement, because I very much see it as a transformer which is VERY efficient and not as you stated "albiet a very inefficient one". Can you explain to me how a stagger tuned antenna migrate into inefficient radiators? Seems to me that Thevenin's theorem would show this as being incorrect ! Well, two identical antennas spaced a few wavelengths apart can be considered a transformer, but very inefficient compared to a "real" transformer with identical primary and secondary turns, with an appropriate toroid core. This would be because the core material will increase the magnetic flux density, and will increase the coupling between the two windings/transducers. Point is, the farther apart the antennas are, the less efficient of a "transformer" they will be. I'm not familiar with stagger tuned antennas, although the name would suggest that it is tuned for multiple resonances, so that the antenna will be broadband. Slick |
"W5DXP" wrote in message ... There's another one of your contradictions. "Cancellation (of two waves) precludes their existance ..."??? How can two waves cancel if they never existed? Once again, you are confusing cause and effect. You are asserting an effect caused by itself. That won't fly. :-) Sorry, Cecil. It's a fact. Cancellation requires at least two waves. :-) Cancellation requires zero waves You can't have it both ways.. Maxwell's equations contain partial differentials for dx, dy, dz, and dt. Yes they do, and for any set of finite values of those variables for two superposed functions of equal amplitude an opposite phase, the solution is zero. You can write the functions for the two waves and prove they cannot exist. You seem incapable of conceiving of canceling wavefronts that exist for only a dt of time. Since the functions cancel during that dt of time as well as any other length of time, you're right. .. I, OTOH, am completely incapable of conceiving of the cancellation of two waves that never existed. Not my problem. 73, ac6xg |
W5DXP wrote:
They say that reflected traveling waves disappear when steady-state is reached. I say such a disappearing act would have to be magic. Just hours earlier you were flinging insults at me for disputing your claim that reflected traveling waves disappear in the steady state. ac6xg |
Jim Kelley wrote:
"W5DXP" wrote: There's another one of your contradictions. "Cancellation (of two waves) precludes their existance ..."??? How can two waves cancel if they never existed? Once again, you are confusing cause and effect. You are asserting an effect caused by itself. That won't fly. :-) Sorry, Cecil. It's a fact. It may be a truth, but only in your mind. It is certainly not a fact. Cancellation requires at least two waves. :-) Cancellation requires zero waves You can't have it both ways.. Cancellation can occur between zero waves? That's just bafflegab. If zero waves exist, wave cancellation is impossible. Maxwell's equations contain partial differentials for dx, dy, dz, and dt. Yes they do, and for any set of finite values of those variables for two superposed functions of equal amplitude an opposite phase, the solution is zero. You can write the functions for the two waves and prove they cannot exist. You are again confusing cause and effect. The solution is zero in only one direction in a transmission line and we already know that. The principle of conservation of energy dictates that the solution cannot be zero in the opposite direction. The two rearward-traveling wavefronts cancel each other. Their intrinsic energy components cannot be canceled. Therefore, that intrinsic energy changes directions and joins the forward wave. It is all explained on the Melles-Griot web page. You seem incapable of conceiving of canceling wavefronts that exist for only a dt of time. Since the functions cancel during that dt of time as well as any other length of time, you're right. Your inability to conceptualize is your problem, not mine. My dog shares that mental problem with you but I love her anyway. I, OTOH, am completely incapable of conceiving of the cancellation of two waves that never existed. Not my problem. Certainly not mine. Do you really expect any rational person to accept your assertion that wave cancellation occurs between wavefronts that never existed? Do you also believe that marriages occur between men and women who never existed? -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
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(Art Unwin KB9MZ) wrote in message om...
Roy Lewallen wrote in message ... I hope you'll pardon me for amplifying this a little. If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. Yes Roy. The specifics of what is being discussed is all important when looking at answers as well as what terms are being used to measure 'efficiency' and to what ends. Roy is correct. And if both transmit and receive antennas were directional Yagis pointed at each other instead of regular dipoles, the efficiency would go up. As you are surely awawe I too look at antennas as transformers or coupled circuits and thus the primary contributes very much in its own way as far as radiation as does the secondary. Thus 'efficiency' as a criteria of 'value' is all important when using it as a term since as you point out it is a ratio of two terms both of which have to be made very clear for the term efficiency to be made clear Thus in stagger tuning it is important to define your requirements in terms of bandwidth (dual frequency radiation) or max gain ( dual radiators on the same frequency),the above bearing little difference to old time receiver designwith multiple I.F. cans. It is in this areana that I view stagger tuning or coupling as being efficient in charactor. If I am incorrect in the above assumptions I would welcome any correction from those well versed inthe field. Best regards Art Broadbandedness by itself is not a measure of efficiency. You may still be very inefficient, over many octaves! Slick If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL Dr. Slick wrote: (Art Unwin KB9MZ) wrote in message m... 1. Two antennas (also called transducers) placed close together actually can be considered a transformer, albeit a very inefficient one. Humm...By antenna I assume it also means a radiator. This would suggest that a stagger tuned radiators would fall into the catagory discussed above. Now I have a problem with that statement, because I very much see it as a transformer which is VERY efficient and not as you stated "albiet a very inefficient one". Can you explain to me how a stagger tuned antenna migrate into inefficient radiators? Seems to me that Thevenin's theorem would show this as being incorrect ! Well, two identical antennas spaced a few wavelengths apart can be considered a transformer, but very inefficient compared to a "real" transformer with identical primary and secondary turns, with an appropriate toroid core. This would be because the core material will increase the magnetic flux density, and will increase the coupling between the two windings/transducers. Point is, the farther apart the antennas are, the less efficient of a "transformer" they will be. I'm not familiar with stagger tuned antennas, although the name would suggest that it is tuned for multiple resonances, so that the antenna will be broadband. Slick |
W5DXP wrote in message ...
Roy doesn't seem to appreciate me making hamburger out of ham radio's sacred cows. :-) I actually enjoy the T-Bones best of all. I didn't forget the smiley face, an indication of a joke. Remember jokes? -- 73, Cecil http://www.qsl.net/w5dxp I read jokes everytime i read your postings, Cecil. :( Slick |
Jim Kelley wrote:
W5DXP wrote: They say that reflected traveling waves disappear when steady-state is reached. I say such a disappearing act would have to be magic. Just hours earlier you were flinging insults at me for disputing your claim that reflected traveling waves disappear in the steady state. Such a bold-faced lie. I have argued loud and long with Peter (and others) that reflected traveling waves are alive and well during the steady-state. Peter will (hopefully) jump in and verify that fact. Why do you give in to your compulsion to lie about what I have said? Anyone following this discussion can observe what you are tring to do. Why can't you just stick to the technical discussion without having to lie? Because you want to win the argument at any ethical cost? For the record: I think that the forward and reflected waves detected by a Bird wattmeter are really there, transporting the energy and momentum that all EM waves possess. You are the one who claims that those reflected waves from a mismatched load transfer no energy and possess no momentum. That is, unless they are going to encounter a resistor in the future in which case, they are required to predict the future better than you can. Do you realize that your waves are smarter than you are? OTOH, I believe Hecht when he says: "One of the most significant properties of the electromagnetic wave is that is transports energy and momentum." You seem to have chosen to dispute and attempt to discredit Hecht, Ramo & Whinnery, the Melles-Griot web page, and HP Application Notes. Don, good luck on dueling with windmills. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
Art figured out that:
Richard if you have to swipe at me then you need a mean streak like Yuri who uses it with vigor which you do not have. Yuri likes propagation of radio waves and well performing antennas, he hates propagation of crap and misinformation if he stumbles on it. He doesn't care if it is Art, Freak or Tom. So far he has been more (always) right than wrong and he can spell despite of not learning English (his 7th language) at schools. Sometimes he is trying to be funny, but that is judged by the audience. If Art tries one program (AO) and makes recommendation and "evaluation" of modeling software based on that, then he uses his "mean vigor streak" to debunk another crap. He looked at few other programs and knows that AO is still good but a bit archaic and limited. He also has seen different dimensions coming from AO optimizer and others. Who to trust? Need to get the hardware models out and correlate. Art please use spell checker (or slide rule) because you are putting Englishpersons (xG) in bad light. Bada Vigor BUm |
Dr. Slick wrote:
I read jokes everytime i read your postings, Cecil. I have requested that you list just one point of technical disagreement between you and me, but so far you have refused and only responded with ad hominem attacks. What can we deduce from that fact? -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
W5DXP wrote: Jim Kelley wrote: W5DXP wrote: They say that reflected traveling waves disappear when steady-state is reached. I say such a disappearing act would have to be magic. Just hours earlier you were flinging insults at me for disputing your claim that reflected traveling waves disappear in the steady state. Such a bold-faced lie. I have argued loud and long with Peter (and others) that reflected traveling waves are alive and well during the steady-state. Peter will (hopefully) jump in and verify that fact. You're arguing with me about it right now in another thread! :-) Don, good luck on dueling with windmills. I'm not trying to sell something, Bill, you are. You're trying to get publications to buy into your energy reversal theory. You'll need lots of luck with that. 73, ac6xg |
Jim Kelley wrote:
These waves never propagate. Of course not and I NEVER said they did. That's just another strawman of yours. The wavefronts originate in and are canceled in a 'dt' of time. What is it about calculus that you do not understand? Cancellation can occur between zero waves? No. Zero waves occur because of cancellation. Bafflegab!!! The energy in the waves CANNOT be destroyed. Zero waves occur in one direction. The energy in the canceled waves flows in the opposite direction. So says every physics book that I own. Sorry about that. You have said: Waves cannot just "cease to exist" for the very same reason that energy cannot cease to exist. This is the biggest bunch of BS that you have ever uttered! On what planet do you live that photons must be conserved? The waves which impinge upon the boundary certainly exist. But V3 and V4 do not exist because their existance is prevented. Without their existence, wave cancellation is impossible. Yet you have agreed that wave cancellation exists. Which is it? Does wave cancellation exist? If yes, then V3 and V4 exist. If no, then come up with an explanation that doesn't involve wave cancellation. (Your spelling of "existance" sic, is driving me crazy. Please correct it.) To you that is a truth. But it certainly is not a fact. And you certainly can't dispute that for any set of finite values of those variables for two superposed functions of equal amplitude an opposite phase, the solution is zero. What you are missing is that your solution is only for one direction. The other direction contains the reflected energy as proven by a Bird directional wattmeter. Aren't you capable of conceptual thoughts involving the two directions in a one-dimensional environment? My dog is almost capable of that. Are you claiming that a wave in a transmission line can move in more than one direction at a time? No, I am claiming that the energy in waves can reverse direction in a 'dt' of time. Do you disagree? :-) Actually, it's not quite that specific. The conservation of energy principle says that energy in equals energy out minus losses. Bafflegab! The conservation of energy principle says the energy in an electron can be tracked to an electron plus photon and back. Good Grief! Are you really teaching physics students? If so, I feel sorry for them. Does your boss know that your are teaching bafflegab? There is no intrinsic energy in waves that never propagate. _Optics_, by Hecht says that all EM waves propagate and contain energy and momentum. Sorry about that. Once you get an idear in ur head, there's no shiftin' it. I really admire your technical assertions, I really do. When are you going to make one? Your inability to conceptualize is your problem, not mine. So you're claiming that the functions don't cancel during time dt? Of course, they cancel during time dt. Why do you feel the compulsion to erect those more-than-obvious strawmen? That's usually the diversion of someone who is desperate after painting himself into a corner. Why do you feel the need for diversions? Why can't you just discuss the technical aspects? Do you really expect anyone to believe that waves can both exist and not exist at the same time? No, that's just one of your strawmen. I expect some people to accept the fact of physics that a wave can be destroyed by wave cancellation as described in _Optics_, by Hecht and on the Melles-Griot web page. -- 73, Cecil http://www.qsl.net/w5dxp "One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike ..." Albert Einstein -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- |
W5DXP wrote:
Jim Kelley wrote: These waves never propagate. Of course not and I NEVER said they did. That's just another strawman of yours. The wavefronts originate in and are canceled in a 'dt' of time. The same 'dt' of time. The waves would cancel for any t and any x. What a ridiculous argument to be having. Cancellation can occur between zero waves? No. Zero waves occur because of cancellation. The energy in the waves CANNOT be destroyed. Zero waves=zero energy. Zero waves occur in one direction. That's what I just got done saying and you called it "bafflegab" or some such thing. The energy in the canceled waves flows in the opposite direction. The energy definitely flows in the opposite direction - from source to load. You keep claiming it's flowing toward the source. That's what the argument is about. Remember? The waves which impinge upon the boundary certainly exist. But V3 and V4 do not exist because their existance is prevented. Without their existence, wave cancellation is impossible. They don't exist, and there's nothing besides cancellation to explain their absence. Yet you have agreed that wave cancellation exists. Which is it? Does wave cancellation exist? If yes, then V3 and V4 exist. Wave cancellation exists, and as a result V3 and V4 do not. Very simple. (Your spelling of "existance" sic, is driving me crazy. Please correct it.) Short drive, methinks. What you are missing is that your solution is only for one direction. There is only one solution to that equation - and it is for one direction only. The forward moving energy is expressed by a different equation, obviously with a different solution. The other direction contains the reflected energy as proven by a Bird directional wattmeter. Yes, the wattmeter says 133.33 in one direction and 33.33 in the other direction. Are you claiming that a wave in a transmission line can move in more than one direction at a time? No, I am claiming that the energy in waves can reverse direction in a 'dt' of time. Do you disagree? A wave going in a different direction is kind of a different wave, to my way of thinking. Maybe you could ask your dog what he thinks about that, and let us know. The conservation of energy principle says that energy in equals energy out minus losses. Bafflegab! So are you saying that energy is not conserved when energy in equals energy out, minus losses? Or are you saying that energy is conserved when energy in does not equal energy out, minus losses? Does your boss know that your are teaching bafflegab? Actually, he says that I'm conversing with a nutcase. |
Cec sed -
What is it about calculus that you do not understand? ============================= Cec, and to whom it may concern, Probably most of it. Here in Euro-side an amateur radio ticket can be obtained without ever having heard of it. And what with present educational standards that's nearly all of us. The trouble with Guru's displaying their knowledge on this newsgroup is failure to appreciate the technical standing of their 'pupils'. Yet as often as not the manner in which questions are asked are a dead giveaway. For a reply to be of value it is necessary for the Guru to 'tune in' to the recipient, ie., become resonant in same sort of language. Too seldom is any thought given to it. As a result I would guess many questioners become so confused or overloaded with haggling between the 'experts' they don't bother reading to the end of the thread, possibly to consider packing up the hobby. It is impossible for a novice in a particular subject to distinguish wheat from chaff, or to choose between one old-wive's tale and another. Confusion reigns! So KISS ! In plain unabbreviated English. To refer to Terman et al to somebody who has probably never heard of any of 'em is no better than uninvited spam and indicates a lack of self confidence. But who am I to lay down the Law? Tonight's plonk is Claret. Vive La France! Hic! ---- Reg, G4FGQ |
Reg Edwards wrote:
So KISS ! In plain unabbreviated English. That's exactly what I try to do, Reg. But everyone keeps asking me to prove my concepts using Maxwell's equations, as if that was possible on an ASCII newsgroup. My attitude is: If they are incapable of arguing concepts, then they probably don't know what they are talking about anyway. When I ask for a conceptual thumbnail sketch and am refused, that's exactly what I assume. Even Einstein was capable of presenting his relativity concepts in a language that most technical people could understand. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
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W5DXP wrote:
Jim Kelley wrote: You're arguing with me about it right now in another thread! :-) If you really believe that, Jim, you are *extremely* mentally ill. Go obtain some medication for your problem and get back to us. My joke was apparently too subtle. It is impossible for me to be reading this thread "right now" while arguing with Jim "right now" on another thread. Sorry, it was a poor attempt at a play on the words, "right now". I certainly don't think Jim is mentally ill. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
Cecil wrote,
My joke was apparently too subtle. It is impossible for me to be reading this thread "right now" while arguing with Jim "right now" on another thread. Sorry, it was a poor attempt at a play on the words, "right now". I certainly don't think Jim is mentally ill. -- 73, Cecil http://www.qsl.net/w5dxp No, but he will be if he keeps arguing with you. Most of the rest of us value our mental health too much to argue an infinite thread with an obsessed Texan. 73, Tom Donaly, KA6RUH |
Cec, from where do you get all your energy?
Is it from fire water you have now stopped trading for buffalo hides from the injuns? --- Reg |
Art Unwin wrote:
"As far as I am concerned you do not have the faintest idea what my antenna consists of ...or,,you don`t know what you are talking about." How does Art`s antenna differ from Fig 10(A) on page 26-9 of the 19th edition of the ARRL Antenna Book?. In that figure, the input of the "T" is inductive until the series capacitance brings it into resonance. The tuning section of Fig 10(A) forms a small loop. See Fig 4 on page 5-3 of the same Antenna Book for the small loop radiation pattern. Also, see Fig 12 on page 2-8 for the dipole radiation pattern. Note that lobes are perpendicular to the wire and plane of the dipole, and perpendicular to the axis of the small loop. There are nulls perpendicular to the wire and plane of the loop. The loop`s null can`t help the dipole`s lobe. It can`t hurt it either, other than by radiating some energy that might otherwise have gone into the dipole. As the loop is small ( 0.1 lambda is one definition), its contribution to radiation may be small. As the loop size grows, so will its radiation, and its null will decline. How does Art`s antenna differ from a T-matched dipole? Best regards, Richard Harrison, KB5WZI |
Reg Edwards wrote:
Cec, from where do you get all your energy? A congenital insatiable thirst for knowledge. I asked my first grade teacher, "Why is one plus one equal to two?" She didn't know. I finally got my answer years later when I took a "Foundations of Mathematics" college course. -- 73, Cecil, W5DXP |
Dr Slick.
When the term efficiency is used on this newsgroup it always leads to dissention. As Roy pointed out efficiency is a ratio between two factors X and Y only. Unfortunately in this newsgroup people have a tendency to use Y in their derivation of efficiency which results in people talking past each other. I suspect we have a bit of that in this thread Have a great day Art (Dr. Slick) wrote in message . com... (Art Unwin KB9MZ) wrote in message om... Roy Lewallen wrote in message ... I hope you'll pardon me for amplifying this a little. If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. Yes Roy. The specifics of what is being discussed is all important when looking at answers as well as what terms are being used to measure 'efficiency' and to what ends. Roy is correct. And if both transmit and receive antennas were directional Yagis pointed at each other instead of regular dipoles, the efficiency would go up. As you are surely awawe I too look at antennas as transformers or coupled circuits and thus the primary contributes very much in its own way as far as radiation as does the secondary. Thus 'efficiency' as a criteria of 'value' is all important when using it as a term since as you point out it is a ratio of two terms both of which have to be made very clear for the term efficiency to be made clear Thus in stagger tuning it is important to define your requirements in terms of bandwidth (dual frequency radiation) or max gain ( dual radiators on the same frequency),the above bearing little difference to old time receiver designwith multiple I.F. cans. It is in this areana that I view stagger tuning or coupling as being efficient in charactor. If I am incorrect in the above assumptions I would welcome any correction from those well versed inthe field. Best regards Art Broadbandedness by itself is not a measure of efficiency. You may still be very inefficient, over many octaves! Slick If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL Dr. Slick wrote: (Art Unwin KB9MZ) wrote in message m... 1. Two antennas (also called transducers) placed close together actually can be considered a transformer, albeit a very inefficient one. Humm...By antenna I assume it also means a radiator. This would suggest that a stagger tuned radiators would fall into the catagory discussed above. Now I have a problem with that statement, because I very much see it as a transformer which is VERY efficient and not as you stated "albiet a very inefficient one". Can you explain to me how a stagger tuned antenna migrate into inefficient radiators? Seems to me that Thevenin's theorem would show this as being incorrect ! Well, two identical antennas spaced a few wavelengths apart can be considered a transformer, but very inefficient compared to a "real" transformer with identical primary and secondary turns, with an appropriate toroid core. This would be because the core material will increase the magnetic flux density, and will increase the coupling between the two windings/transducers. Point is, the farther apart the antennas are, the less efficient of a "transformer" they will be. I'm not familiar with stagger tuned antennas, although the name would suggest that it is tuned for multiple resonances, so that the antenna will be broadband. Slick |
Dr Slick.
When the term efficiency is used on this newsgroup it always leads to dissention. As Roy pointed out efficiency is a ratio between two factors X and Y only. Unfortunately in this newsgroup people have a tendency to use Y in their derivation of efficiency which results in people talking past each other. I suspect we have a bit of that in this thread Have a great day Art (Dr. Slick) wrote in message . com... (Art Unwin KB9MZ) wrote in message om... Roy Lewallen wrote in message ... I hope you'll pardon me for amplifying this a little. If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. Yes Roy. The specifics of what is being discussed is all important when looking at answers as well as what terms are being used to measure 'efficiency' and to what ends. Roy is correct. And if both transmit and receive antennas were directional Yagis pointed at each other instead of regular dipoles, the efficiency would go up. As you are surely awawe I too look at antennas as transformers or coupled circuits and thus the primary contributes very much in its own way as far as radiation as does the secondary. Thus 'efficiency' as a criteria of 'value' is all important when using it as a term since as you point out it is a ratio of two terms both of which have to be made very clear for the term efficiency to be made clear Thus in stagger tuning it is important to define your requirements in terms of bandwidth (dual frequency radiation) or max gain ( dual radiators on the same frequency),the above bearing little difference to old time receiver designwith multiple I.F. cans. It is in this areana that I view stagger tuning or coupling as being efficient in charactor. If I am incorrect in the above assumptions I would welcome any correction from those well versed inthe field. Best regards Art Broadbandedness by itself is not a measure of efficiency. You may still be very inefficient, over many octaves! Slick If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL Dr. Slick wrote: (Art Unwin KB9MZ) wrote in message m... 1. Two antennas (also called transducers) placed close together actually can be considered a transformer, albeit a very inefficient one. Humm...By antenna I assume it also means a radiator. This would suggest that a stagger tuned radiators would fall into the catagory discussed above. Now I have a problem with that statement, because I very much see it as a transformer which is VERY efficient and not as you stated "albiet a very inefficient one". Can you explain to me how a stagger tuned antenna migrate into inefficient radiators? Seems to me that Thevenin's theorem would show this as being incorrect ! Well, two identical antennas spaced a few wavelengths apart can be considered a transformer, but very inefficient compared to a "real" transformer with identical primary and secondary turns, with an appropriate toroid core. This would be because the core material will increase the magnetic flux density, and will increase the coupling between the two windings/transducers. Point is, the farther apart the antennas are, the less efficient of a "transformer" they will be. I'm not familiar with stagger tuned antennas, although the name would suggest that it is tuned for multiple resonances, so that the antenna will be broadband. Slick |
Reg Edwards wrote:
Here in Euro-side an amateur radio ticket can be obtained without ever having heard of it. And what with present educational standards that's nearly all of us. The trouble with Guru's displaying their knowledge on this newsgroup is failure to appreciate the technical standing of their 'pupils'. Yet as often as not the manner in which questions are asked are a dead giveaway. For a reply to be of value it is necessary for the Guru to 'tune in' to the recipient, ie., become resonant in same sort of language. Too seldom is any thought given to it. As a result I would guess many questioners become so confused or overloaded with haggling between the 'experts' they don't bother reading to the end of the thread, possibly to consider packing up the hobby. It is impossible for a novice in a particular subject to distinguish wheat from chaff, or to choose between one old-wive's tale and another. Confusion reigns! My assessment as one of the "less washed" is that I can kind of understand some of what is being argued. But too much pouncing on minutaia, too much of what sounds like the antagonists saying the same thing in a different way, and too much personal junk all over the place, and it ends up doing everyone no good at all, especially the antagonists. But of course, it doesn't really matter what I think. I suspect that despite some aggravation and digestive tract angst, they are enjoying it. In the end, it is just a Warholesqe repetitive, stretched out artwork. So KISS ! In plain unabbreviated English. Or (ironically enough -- Occam's Razor!!-- 8^) - Mike KB3EIA - |
Jim Kelley wrote:
W5DXP wrote: Such a bold-faced lie. I have argued loud and long with Peter (and others) that reflected traveling waves are alive and well during the steady-state. Peter will (hopefully) jump in and verify that fact. You're arguing with me about it right now in another thread! :-) The statement, "Reflected traveling waves disappear in the steady state", means to me that the set of reflected traveling waves is null in the steady-state - which is a statement that I never made. In a system with a mismatched load, reflected traveling waves always exist and I have NEVER said otherwise. Semantic tricks and traps never prove anything. They just obfuscate. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
Reg Edwards wrote: Cec, from where do you get all your energy? Simple - from reflected and collected waves, and rest converted to infrared energy not radiated by the heat sink. :-) A congenital insatiable thirst for knowledge. I asked my first grade teacher, "Why is one plus one equal to two?" She didn't know. I finally got my answer years later when I took a "Foundations of Mathematics" college course. -- 73, Cecil, W5DXP That's where its coming from! The only problem is that the more we learn we find out that we know less and still die stupid. Bada 3BUm |
Mike sez -
I suspect that despite some aggravation and digestive tract angst, they are enjoying it. ============================= Mike, you are undoubtedly correct. If you ask a man why he keeps banging his head with a hammer he will reply that he likes the feeling when he stops. To put it in engineering terms, all living and dead materials take the line of least resistance as perceived by their senses at the present instant of time. The result is an unending drunken "Monte-Carlo" walk. At MY present instant in time I am about to pour another glass of delicate Chinese "Great Wall" white wine. If the disused coal mine under this house, a consequence of the industrial revolution, doesn't fall in I may yet survive to enjoy it. There are an infinite number of ways our 'pleasure centers' make good use of amateur radio. Between them Cecil and Co. know them all ! --- Reg, G4FGQ |
Yuri Blanarovich wrote:
The only problem is that the more we learn we find out that we know less and still die stupid. Someone said we specialize to the extent that we know more and more about less and less and wind up knowing everything about nothing. -- 73, Cecil http://www.qsl.net/w5dxp "One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike ..." Albert Einstein -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- |
Richard,
When it comes to looking up books for quotations you do a good enough job to be a librarian, but I am unaware of any instance where a librarian was promoted to the engineering section on a project basis. Each of the instances that you quote are simple and direct..... as long as particular conditions are followed. When you strayed from your books to combine two situations it would be wise for you to analyse the new situation to check for changes in conditions. Unfortuately for you this will not be neatly laid out in your books In the case of a so called magnetic loop there are many conditions to be met to ensure a figure 8 radiation pattern, with or without deep nulls. Thus just any old loop in any sort of conditions such as being coupled to another object or not uniform in cross section e.t.c. is not the same as the conditions that you referenced in the handbook thus statements that regurgitate may well not now apply. It is a pity that you do not have a interest in computor programs or an interest in using one because if you did you could add to your experience without the need of buying another book. (Richard Harrison) wrote in message ... Art Unwin wrote: "As far as I am concerned you do not have the faintest idea what my antenna consists of ...or,,you don`t know what you are talking about." How does Art`s antenna differ from Fig 10(A) on page 26-9 of the 19th edition of the ARRL Antenna Book?. In that figure, the input of the "T" is inductive until the series capacitance brings it into resonance. The tuning section of Fig 10(A) forms a small loop. See Fig 4 on page 5-3 of the same Antenna Book for the small loop radiation pattern. Also, see Fig 12 on page 2-8 for the dipole radiation pattern. Note that lobes are perpendicular to the wire and plane of the dipole, and perpendicular to the axis of the small loop. There are nulls perpendicular to the wire and plane of the loop. The loop`s null can`t help the dipole`s lobe. It can`t hurt it either, other than by radiating some energy that might otherwise have gone into the dipole. As the loop is small ( 0.1 lambda is one definition), its contribution to radiation may be small. As the loop size grows, so will its radiation, and its null will decline. How does Art`s antenna differ from a T-matched dipole? Best regards, Richard Harrison, KB5WZI |
Actually, Art, the dissention is mostly when *you* use the term
efficiency, because for reasons of your own, you don't use it in the universally understood way. Roy Lewallen, W7EL Art Unwin KB9MZ wrote: Dr Slick. When the term efficiency is used on this newsgroup it always leads to dissention. As Roy pointed out efficiency is a ratio between two factors X and Y only. Unfortunately in this newsgroup people have a tendency to use Y in their derivation of efficiency which results in people talking past each other. I suspect we have a bit of that in this thread Have a great day Art |
Art Unwin KB9MZ wrote:
Roy, the die was cast years ago when anything "new" was trashed without a hearing. I now accept that all is now known about antennas except the really deep things that Cecil is so bravely pushing on with where I failed. One slight correction, Art. Because of the similarity between light and radiated EM waves, most things about antennas are known, at least to the limit of the models to handle reality. However, it appears to me that some things have been overlooked when the coherent EM waves are confined to a one-dimensional transmission line. Those things that have been overlooked are what I am pursuing and as far as I can determine, they happen only inside a transmission line or at a thin-film non-reflective surface using coherent light waves. That's what makes it special. That is not to conclude that you haven't discovered something special, just that my focus is Z0-match points inside transmission lines and non-glare thin-film coatings involving orthogonal coherent light. -- 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 80,000 Newsgroups - 16 Different Servers! =----- |
Art Unwin wrote:
"It is a pity you do not have an interest in computor programs---." If Art would publish impedance, gain, directivity, and bandwidth comparisons of his antenna against a reference dipole at the same height, from his computer programs, we might all know more about it. Best regards, Richard Harrison, KB5WZI |
|
Just playing devels advocate here, but, as you state "If you put X watts
into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency.", does that refer to the 377 ohms (or so) free space coupling impedence, or could that effeciency be improved by having the antenna's matched radiation resistance approach that 377 ohms? (I.E. max transfer of power is at Z0 (in) matches Z0(out)! or, is this academic for this? Perhaps, better for Dr. Shorza Gitchigoumi of CQ fame, or Larson E. Rapp of ARRL fame (both with bad habit of only presenting articles in the 4th month of the year in their respective publications) ! But, I'd thought I had better ask! Jim NN7K "Roy Lewallen" wrote in message ... I hope you'll pardon me for amplifying this a little. If you put X watts into the primary of a transformer and extract Y watts from the secondary, the efficiency is Y/X by definition. If you put X watts into one antenna and extract Y watts from an antenna coupled to it, and measure the efficiency of the "transformer" the same way as you did the conventional transformer, you'll find it has lousy efficiency. Why? Because a goodly fraction of the power you applied to the "primary" antenna never gets to the "secondary" antenna because it's radiated instead. As far as the "secondary" is concerned, it might as well have been converted to heat. If you look at the impedance of the "primary" antenna, you'll find an excess of resistance -- just enough, in fact, to account for the "lost" (radiated) power. This isn't a statement about how well coupled antennas function as antennas, whose purpose is to radiate after all. It's a statement about how well they function as a transformer. Poorly. Roy Lewallen, W7EL |
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