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Walter:
I thought you were just playing on a bit with my joke... I am sorry... Let me explain, Reg made reference to the venerable "Jones Chart" in a previous post in this thread--it was too temping a joke to leave alone and I picked up upon it--I make no real claim my father had any hand in the creation of the smith chart--again, I am sorry, but I thought you just playing along--to tell you the truth, I am still not absolutely sure you are not--you still might be... grin (the only hand my father played in all this was to teach me, "Take it like a man son!!! ... and blame it on a Brit!!! ... poor Reg... grin) Warmest regards, John "Walter Maxwell" wrote in message ... "Richard Clark" wrote in message ... On Fri, 3 Jun 2005 10:49:58 -0400, "Walter Maxwell" wrote: John, are you telling us that Phillip H. Smith was your Father? Hi Walt, I'm sorry to have the distinction of telling you that you have now twice tried to bite at air in two postings to the same thread. [Outlook Express is a jinx for you to use!] There is no "John Smith" corresponding to this group. Brett uses this "handle" for whatever reason, but certainly not because he thinks that his veil is impenetrable. 73's Richard Clark, KB7QHC Holy Cow, Richard, you've just diagnosed the pain in my jaw. Silly me. I guess that means that the 'John Smith' we're corresponding with came over on the Mayflower. Walt, W2DU |
Regarding the long-lasting, 67-years old, love affair with the Smith Chart. Where there's Love there's Beauty. The beauty of a Smith Chart derives from the underlying Mathematics. Mathematics is pure intellectual beauty. In this case the underlying functions and their inverses are the Complex Hyperbolic Functions like Sinh, Cosh and Tanh which Victorian engineers were familiar with. The behaviour of the early telegraph, telephone and power lines was exactly described by such functions. The maths had been quietly waiting for many years for transmission lines to be invented. In the absence of computers, engineers soon got fed up with designing transmission lines, solving complex hyperbolic equations with the aid of log tables and slide rules, and began to use graphical methods in the form of charts. Now, complex hyperbolic functions are 3 dimensional things. They have two linear dimensions and angles. They cannot be represented on a flat paper chart. They need a whole stack of charts. Such stacks of charts were available round about the Boer War. So whilst the British Army was setting up concentration camps in South Africa, phone engineers were busy in their factory offices worrying about SWR on power and long-distance telephone lines. The Victorian multi-dimensional charts remained in use through the days of VLF and LF radio and for 5 decades until the advent of computers. Bear in mind the charts were just a more convenient means of accessing data than from books of mathematica tables, although they were of much lower precision. See if you can find it - "A Chart Atlas of Complex Hyperbolic Functions", A. E. Kennelly, Harvard University, 1914. Worldwide HF radio rapidly expanded from the early 1930's. In 1938 a certain Mr Smith noticed that at HF and higher frequencies, for rough and ready calculations he had to use only one of the stack of charts. This particular chart corresponded to the case of a lossless line and when Zo was purely resistive. No real lines have zero loss or have a purely resistive Zo. But practical lines have a sufficiently low attenuation per wavelength and a Zo whose angle converges towards zero with increasing frequency, for a single chart on a flat sheet of paper to deal with sufficient accuracy calculations at frequencies down to LF. So Mr Smith exercised his artistic talents to produce the chart we are familiar with. Or at least which we have heard about. ---- Reg. "Reg Edwards" wrote in message ... Reg, you've aroused my curiosity on three points: Why would you use 'Smith Chart' and 'anger' in the same sentence? ======================================== Just a figure of speech. "Anger" suggests setting about a job with energy, determination and a sense of purpose. As distinct from mere amusement. ======================================== Why are there any frequencies where the Smith Chart is misleading and useless? Which frequencies are they? ======================================== Depending on the size of the errors one is prepared to tolerate and on the calculated parameter of interest - Frequencies at which line attenuation per wavelength is not small. Frequencies at which Zo is not purely real. Frequencies at which CR is not equal to LG. Frequencies at which the reflection coefficient is greater than 1.0 Comment : Zo is never purely real. CR is never equal to LG. And the chart is good only to 2-digit accuracy anyway. But Walt, you already know all this. Have you ever tried the Jones Chart? ;o) ======================================== How can you say the Smith Chart is misleading and useless if you've never used one, and never inspected one for more than a minute? Walt, W2DU ======================================== No problem! Worked it out for myself many years ago. Some years ago I introduced to this newsgroup the excellent book "Transmission Lines" by Robert A. Chipman, 1968. It aroused some interest. Some of you obtained a copy. It has a whole chapter devoted to the Smith Chart and fully describes its limitations, imperfections, short-comings and approximations. But the reason Chipman included the chapter was because of the great savings in labour and time (in HIS day and age) when doing approximate calculations on short, low loss, HF transmission lines such as antenna feedlines for which it was designed. Which is all radio amateurs ever use it for. Hardly any amateurs ever use it in anger. It has other applications. I first programmed a computer for work on transmission lines around 1960. At frequencies between 0.1 Hz and 1 MHz, frequencies at which nobody would dream of using a Smith Chart. So I never became addicted to it. ---- Reg. |
On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote: See if you can find it - "A Chart Atlas of Complex Hyperbolic Functions", A. E. Kennelly, Harvard University, 1914. Hi Reg, A rare citation indeed, following an equally rare citation (Kennelly following Smith, that is, and rare meaning a citation offered by you who usually claim such activity reveals plagiarism). But as for your challenge (yes a heated term I suppose - but still...): Google "Complex Hyperbolic Functions" Kennelly to find from: http://www.geocities.com/neveyaakov/.../kennelly.html "Arthur Edwin Kennelly was U.S. electrical engineer who made innovations in analytic methods in electronics, particularly the definitive application of complex-number theory to alternating-current (ac) circuits." Let me quickly add that Kennelly was US through immigration and professional employment, but British schooled and trained. Such an introduction would put your comment to the test: The Victorian multi-dimensional charts remained in use through the days of VLF and LF radio and for 5 decades until the advent of computers. Which on one hand would suggest rather Edwardian than Victorian, and on the other hand, perhaps Wilsonian for where this tome was actually published. 73's Richard Clark, KB7QHC |
"Richard Clark" wrote in message ... On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards" wrote: See if you can find it - "A Chart Atlas of Complex Hyperbolic Functions", A. E. Kennelly, Harvard University, 1914. Hi Reg, A rare citation indeed, following an equally rare citation (Kennelly following Smith, that is, and rare meaning a citation offered by you who usually claim such activity reveals plagiarism). But as for your challenge (yes a heated term I suppose - but still...): Google "Complex Hyperbolic Functions" Kennelly to find from: http://www.geocities.com/neveyaakov/.../kennelly.html "Arthur Edwin Kennelly was U.S. electrical engineer who made innovations in analytic methods in electronics, particularly the definitive application of complex-number theory to alternating-current (ac) circuits." Let me quickly add that Kennelly was US through immigration and professional employment, but British schooled and trained. Such an introduction would put your comment to the test: The Victorian multi-dimensional charts remained in use through the days of VLF and LF radio and for 5 decades until the advent of computers. Which on one hand would suggest rather Edwardian than Victorian, and on the other hand, perhaps Wilsonian for where this tome was actually published. 73's Richard Clark, KB7QHC I have a copy of Kennelly's "A Chart Atlas of Complex Hyperbolic Functions", in my library in Florida. I'd be pleased to scan it for anyone who'd like a copy, but only if you have the patience to wait until I return south in November. Walt, W2DU |
On Fri, 3 Jun 2005 14:14:35 -0400, "Walter Maxwell"
wrote: I have a copy of Kennelly's "A Chart Atlas of Complex Hyperbolic Functions", in my library in Florida. I'd be pleased to scan it for anyone who'd like a copy, but only if you have the patience to wait until I return south in November. Hi Walt, I cannot imagine that but being a very lengthy chore. However, it is quickly becoming one that more than a few are willing to perform and I offer to one and all my congratulations and thanks for such effort. I will pass on this if I am your only motivation. I have a copy of "Standard Handbook for Electrical Engineers," McGraw - Hill, that is contemporaneous. It comes with many such charts, tables, figures, and minutia in the classical Wilsonian style of illustration (and I cannot imagine myself copying all 2000 pages for circulation). 73's Richard Clark, KB7QHC |
Cecil:
I must say, you are quite a talent, your threads draw more attention, debate, argument and blood to boil--that I grow ill with jealousy!!! grin Warmest regards, John "Cecil Moore" wrote in message ... I've added a Smith Chart graphic to my All-HF-Band-No-Tuner-Antenna information on my web page. -- 73, Cecil http://www.qsl.net/w5dxp/smith.htm ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Regarding transmission lines, as somebody who has never thorougly
learned how to use a Smith Chart, it has never been worth the trouble, I would like to say that the underlying, common sense, logical mathematics are much easier to understand. ---- Reg |
Reg:
As usual you are right on key... If you know math, if you are not afraid of using complex formulas in computations (and especially if you have a programmable calculator in your back pocket) the math is much more appealing than charts--still, the chart has uses... not all directly related to the math (my gf's think they look kewl--frankly, I might get laid a tad more often just for displaying a smith chart--women are hung up on intelligent men yanno--I wonder if smith ever realized that? grin)... Warmest regards, John "Reg Edwards" wrote in message ... Regarding transmission lines, as somebody who has never thorougly learned how to use a Smith Chart, it has never been worth the trouble, I would like to say that the underlying, common sense, logical mathematics are much easier to understand. ---- Reg |
On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote: The beauty of a Smith Chart derives from the underlying Mathematics. Mathematics is pure intellectual beauty. |
On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote: The beauty of a Smith Chart derives from the underlying Mathematics. Mathematics is pure intellectual beauty. In this case the underlying functions and their inverses are the Complex Hyperbolic Functions like Sinh, Cosh and Tanh ... Now, complex hyperbolic functions are 3 dimensional things. They have two linear dimensions and angles. They cannot be represented on a flat paper chart. They need a whole stack of charts. On Sat, 4 Jun 2005 18:30:54 +0000 (UTC), "Reg Edwards" wrote: as somebody who has never thorougly learned how to use a Smith Chart, it has never been worth the trouble, I would like to say that the underlying, common sense, logical mathematics are much easier to understand. Hmm, Same topic, same math, same correspondent, same language (apparently), two different and diverging points of view (the last couched in double negatives) -and- consistent(ly amusing). I am at a loss to read these statements as Art criticism, Pedagogy, Historical Romance, or what? 73's Richard Clark, KB7QHC |
On Sat, 04 Jun 2005 18:01:12 -0700, Richard Clark
wrote: On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards" wrote: The beauty of a Smith Chart derives from the underlying Mathematics. Mathematics is pure intellectual beauty. Hi Reg, My cat Blacky sent that one while walking across the keyboard - purely his choice, he usually prefers the privacy of email. He would have added some comment, but you might know how cats change their mind in the middle of things. 73's Richard Clark, KB7QHC |
I am at a loss to read these statements as Art criticism, Pedagogy,
Historical Romance, or what? 73's Richard Clark, KB7QHC ================================= Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. For some inexplicable reason you have reverted back to Shakesperian poetry. Come back to plain American English. Try the other English (or Irish) playright and iconoclast, George Bernard Shaw. And I hope you don't object if I begin some of my sentences with 'And'. ---- Reg, G4FGQ |
Reg Edwards wrote:
I am at a loss to read these statements as Art criticism, Pedagogy, Historical Romance, or what? 73's Richard Clark, KB7QHC ================================= Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. For some inexplicable reason you have reverted back to Shakesperian poetry. Come back to plain American English. Try the other English (or Irish) playright and iconoclast, George Bernard Shaw. And I hope you don't object if I begin some of my sentences with 'And'. ---- Reg, G4FGQ And why would you want to do that, Reg? I thought that only people of my cultural persuasion began their sentences with 'And'. G.B. Shaw had his moments. He once wrote, "If you do not say a thing in an irritating way, you may as well not say it at all, since nobody will trouble themselves about anything that does not trouble them." 73, Tom Donaly, KA6RUH |
And, there is much truth there Tom... those thoughts are right on!
Warmest regards, John "Tom Donaly" wrote in message ... Reg Edwards wrote: I am at a loss to read these statements as Art criticism, Pedagogy, Historical Romance, or what? 73's Richard Clark, KB7QHC ================================= Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. For some inexplicable reason you have reverted back to Shakesperian poetry. Come back to plain American English. Try the other English (or Irish) playright and iconoclast, George Bernard Shaw. And I hope you don't object if I begin some of my sentences with 'And'. ---- Reg, G4FGQ And why would you want to do that, Reg? I thought that only people of my cultural persuasion began their sentences with 'And'. G.B. Shaw had his moments. He once wrote, "If you do not say a thing in an irritating way, you may as well not say it at all, since nobody will trouble themselves about anything that does not trouble them." 73, Tom Donaly, KA6RUH |
On Sun, 5 Jun 2005 07:32:26 +0000 (UTC), "Reg Edwards"
wrote: Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. Hi Reg, That's OK, we understand each and every chunk of offering you toss to the dog pack. Some is like horse meat, some like fish. If we tried to put it back together we get a chimera. Sorry for that long word, but enough readers already understand. And I hope you don't object if I begin some of my sentences with 'And'. I'm surprised you are really interested in grammar at all! No objection, more work is necessary, but you do show initiative. ;-) 73's Richard Clark, KB7QHC |
I am at a loss to read these statements as Art criticism,
Pedagogy, Historical Romance, or what? 73's Richard Clark, KB7QHC ================================= Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. For some inexplicable reason you have reverted back to Shakesperian poetry. Come back to plain American English. Try the other English (or Irish) playright and iconoclast, George Bernard Shaw. And I hope you don't object if I begin some of my sentences with 'And'. ---- Reg, G4FGQ ==================================== And why would you want to do that, Reg? I thought that only people of my cultural persuasion began their sentences with 'And'. G.B. Shaw had his moments. He once wrote, "If you do not say a thing in an irritating way, you may as well not say it at all, since nobody will trouble themselves about anything that does not trouble them." 73, Tom Donaly, KA6RUH ================================= Tom, Your particular cultural persuasion really doesn't really enter the discussion. It could be North American Red Indian. It sounds OK by me. I imagine most spoken languages admit to the use of 'and' anywhere within the spoken sentence. It is only natural that occasionally it should appear at the beginning of the written sentence. I mentioned it to my friend Richard Clark because of the possibility, of so doing, it may cause irritation and thereby draw his attention to what I was waffling about. There are some silly academic objections to the use of 'And' at the beginning of a written sentence. I was unaware of G.B.Shaw's ideas on how to conduct an irritating conversation. Thank you very much for drawing my attention to his remarks. It is also pleasing to learn that some US citizens are familiar with the works, not just the plays, of GBS. His works have been turned by Hollywood into film - such as Ingrid Bergman as "Saint Joan". But GBS was not happy with the script. The political content of his play was distorted beyond recognition. But that's just Hollywood's pro-american propaganda for you. ---- Reg, G4FGQ |
Reg:
Actually, both you guys are right on, "and" yes--I have always thoroughly enjoyed British theatre and writers... I think their American counterparts have always played a game of "catch up." Today "special effects", sex and "painted blondes" and "action" replace the sorely missed good strong actors and artists... Warmest regards, John "Reg Edwards" wrote in message ... I am at a loss to read these statements as Art criticism, Pedagogy, Historical Romance, or what? 73's Richard Clark, KB7QHC ================================= Richard, I'm afraid I don't understand you. And I doubt if anybody else does either. For some inexplicable reason you have reverted back to Shakesperian poetry. Come back to plain American English. Try the other English (or Irish) playright and iconoclast, George Bernard Shaw. And I hope you don't object if I begin some of my sentences with 'And'. ---- Reg, G4FGQ ==================================== And why would you want to do that, Reg? I thought that only people of my cultural persuasion began their sentences with 'And'. G.B. Shaw had his moments. He once wrote, "If you do not say a thing in an irritating way, you may as well not say it at all, since nobody will trouble themselves about anything that does not trouble them." 73, Tom Donaly, KA6RUH ================================= Tom, Your particular cultural persuasion really doesn't really enter the discussion. It could be North American Red Indian. It sounds OK by me. I imagine most spoken languages admit to the use of 'and' anywhere within the spoken sentence. It is only natural that occasionally it should appear at the beginning of the written sentence. I mentioned it to my friend Richard Clark because of the possibility, of so doing, it may cause irritation and thereby draw his attention to what I was waffling about. There are some silly academic objections to the use of 'And' at the beginning of a written sentence. I was unaware of G.B.Shaw's ideas on how to conduct an irritating conversation. Thank you very much for drawing my attention to his remarks. It is also pleasing to learn that some US citizens are familiar with the works, not just the plays, of GBS. His works have been turned by Hollywood into film - such as Ingrid Bergman as "Saint Joan". But GBS was not happy with the script. The political content of his play was distorted beyond recognition. But that's just Hollywood's pro-american propaganda for you. ---- Reg, G4FGQ |
On Sun, 5 Jun 2005 17:52:50 +0000 (UTC), "Reg Edwards"
wrote: GBS was not happy with the script. The political content of his play was distorted beyond recognition. But that's just Hollywood's pro-american propaganda for you. Hi Reg, They should've stayed with GBS' pro-British propaganda? Or rather his anti-British propaganda? What you offer sounds like a plagiarized play program note. 73's Richard Clark, KB7QHC |
Richard Clark wrote:
On Sun, 5 Jun 2005 17:52:50 +0000 (UTC), "Reg Edwards" wrote: GBS was not happy with the script. The political content of his play was distorted beyond recognition. But that's just Hollywood's pro-american propaganda for you. Hi Reg, They should've stayed with GBS' pro-British propaganda? Or rather his anti-British propaganda? What you offer sounds like a plagiarized play program note. 73's Richard Clark, KB7QHC George Bernard Shaw was a Fabian socialist. He believed that the aim of most people of the society of his day was to become so wealthy as to become economic parasites who didn't produce and didn't contribute. He didn't like this, so he preached against it in his works. Since producing wealthy parasites was what the business side of Hollywood has always been about, it's no wonder they emasculated his script. 73, Tom Donaly, KA6RUH |
On Wed, 01 Jun 2005 23:20:15 -0500, Cecil Moore
wrote: John Smith wrote: I should point out, everyone should at least know about a smith and have used it... kinda gives you a "feel" for the way all the variables work together... it is a good thing... For me, the biggest advantage of the Smith Chart is that I can carry it around in my head. It is a graphical math model of a transmission line. A picture is worth a thousand calculators. Old sayings: A picture is worth a thousand words. A word is worth a thousand pictures ... if it's the right word. |
On Wed, 01 Jun 2005 20:33:05 -0500, Tom Ring
wrote: Hal Rosser wrote: So now you're pickin' on my slide rule? Is nothing sacred?? I like my slide rule. Its more useful than my solar-powered flashlight. The slide rule works without any power or batteries. :-) And its accurate to 3 (sometimes 4) significant digits. Solar powered flashlight? Heck, we have a made up loony lefty here in Minneapolis who wants people to use electric powered generators to reduce noise and pollution during emergencies. Morgan Q. E. Wolfe-Slattery, a true Euphorian. I have 2 slide rules that I picked up recently, but I miss my easy on the eyes yellow aluminum Pickett LogLogDeciTrig (I think that's what it was) that got misplaced during a move a couple decades ago. I also wish I still had my HP35, 45 and 11C. I do have a working HP25, 15C and 48SX though. My sharp stick needs only infrequent exposure to fire to allow me to solve differential equasions. And that's only if there's not a smooth bed of sand nearby. |
On Sun, 05 Jun 2005 20:51:06 GMT, "Tom Donaly"
wrote: George Bernard Shaw was a Fabian socialist. Hi Tom, To amplify, George Bernard Shaw and GBS were two different people. What you offered, following, is true of Shaw. He believed that the aim of most people of the society of his day was to become so wealthy as to become economic parasites who didn't produce and didn't contribute. He didn't like this, so he preached against it in his works. Since producing wealthy parasites was what the business side of Hollywood has always been about, But how he reacted to: it's no wonder they emasculated his script. was as GBS, a one man advertising agency for George Bernard Shaw. In that respect, GBS and Hollywood were on parallel tracks, even if they didn't converge. When GBS/Shaw fulminated, it was over other issues. Basically the Fabian society's ethic was pie-in-the-sky economics that faded with Victoria. Shaw was infinitely more radical, and still more current today than ever with his up-front stories of sexual politics. Absolutely no one goes to a Shavian play to ponder the plight of masses burning the barricades before the classist society. Likewise, no one reads G.K. Chesterton and "The Man Who Was Thursday" when they can catch Father Brown instead. If you had your druthers, would you watch an edited version of "Man and Superman," or its interior play "Don Juan in Hell?" Hollywood rebelled far more vigorously against ALL of Shaw's women protagonists than giving even the slightest thought about any economic theory. Your comment about Hollywood emasculating his scripts; in fact they pumped these scripts up with so much testosterone that "My Fair Lady" is a travesty of a woman submitting to and being redeemed by a man. It is this kind of cheesecake that sells, and selling movies is the ONLY thing Hollywood cares about. If they thought they could sell communism (Warren Beatty's "Reds") then we would have been watching the life of Stalin in technicolor and surround-sound for the past 70 years. Anybody here ever see the movie "Greed?" This came from the pen of Frank Norris, one of the most acidic writers against capitalism ever to come down the pike (and a contemporary of Shaw). Both of these movies were well made, by acclaimed directors and backed with wheelbarrows full of cash. To put it bluntly, neither of these examples drew crowds. Hollywood backs a winner and doesn't give a damn about ANY message as long as it doesn't interfere with selling popcorn. 73's Richard Clark, KB7QHC |
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