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#1
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Chris:
Well, I certainly can see that your claim it is two 1:1 baluns on a single core is technically accurate--the primaries are in parallel and their secondaries are in series... that seems clear enough that it cannot be argued. I can't imagine all NOT to be in agreement on this point. However, with no electrical connection (transmission line) existing between primary/secondary, and the voltage and current only conducted between these windings by a magnetic flux--I CAN'T see how a "true" balun can be argued, clearly--as opposed to "rf transformer." But, I am giving this thought--as I am sure are others... I never thought about the humble "balun"/"rf transformer" in some of these ways before--possibly I am not alone... either and anyway, I enjoy the thinking you have established here... John "Chris Trask" wrote in message link.net... 1. That it is simply a 2:1 transformer with an isolated primary and secondary? No. It is a pair of 1:1 transformers on a single core. I can make it work equally well by making the two transformers on separate cores. I can also make it with a pair of equal length coaxial cables. Both of these realisations defeat his claim that it is a 2:1 transformer. But at the same time, neither of them answer his claim that it is impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers. 2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? This isn't even a gray area. We're making a BALUN, in other words a transformer that has an UNbalanced port and a BALanced port, and in this case fully meeting the definition of a current balun. If we were to accept the above statement, then we would have no choice except to conclude that in no circumstances could we make a BALUN with transmission line transformers because in all cases of BALUNs one port is fed unbalanced. Making transmission line transformers is not difficult, although Tom is making it appear as though it's some sort of great mustery. For a length of transmission line that is sufficiently short with respect to wavelength, meaning less than an eighth of a wavelength in practice, the following rules are observed: 1. The voltage across the one conductor is equal to the voltage of the other conductor, both in magnitude and in phase. 2. The current in the one conductor is equal in magnitude but oppostite in phase to the current in the other conductor. These basic understandings of transmission line transformers are well established and understood. Gary Breed brought the concept down to the essentials in: Breed, Gary, "Transmission Line Transformer Basics," Applied Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60. It all comes down to a difference between what is known by way of established theory and practice versus trying to convince people that everything we know is wrong. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Senior Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks "Ian White GM3SEK" wrote in message ... Chris Trask wrote: It's not a matter of whether I disagree with him or not. It's a matter of him standing on a cybersoapbox and declaring to the world in numerous ways that such a thing cannot work and that only his analysis of how it can and cannot work is valid. He can't deny that he claimed that it was impossible, so now he has to prove that the solution cannot possibly work the way that he knows that it cannot work. Whatever. Please skip the personal rhetoric, and tell us how you respond to his two main technical points about your transformer: 1. That it is simply a 2:1 transformer with an isolated primary and secondary? 2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
#2
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![]() However, with no electrical connection (transmission line) existing between primary/secondary, and the voltage and current only conducted between these windings by a magnetic flux--I CAN'T see how a "true" balun can be argued, clearly--as opposed to "rf transformer." I left out the word "current". My balun is a proper current balun as it meets the formal definition, which is that it maintains currents at the output terminals that are equal in magnitude and opposite in phase regardless of potentials at the output terminals with respect to the ground connection on the unbalanced side. You can find this definition in less strict form in the ARRL handbook, such as 1991 pages 16.8-16.9. The single core Guanella 4:1 current balun meets this definition but only for floating loads. Anything other than that and the two transformers need to be on separate cores. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Senior Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks "John Smith" wrote in message ... Chris: Well, I certainly can see that your claim it is two 1:1 baluns on a single core is technically accurate--the primaries are in parallel and their secondaries are in series... that seems clear enough that it cannot be argued. I can't imagine all NOT to be in agreement on this point. However, with no electrical connection (transmission line) existing between primary/secondary, and the voltage and current only conducted between these windings by a magnetic flux--I CAN'T see how a "true" balun can be argued, clearly--as opposed to "rf transformer." But, I am giving this thought--as I am sure are others... I never thought about the humble "balun"/"rf transformer" in some of these ways before--possibly I am not alone... either and anyway, I enjoy the thinking you have established here... John "Chris Trask" wrote in message link.net... 1. That it is simply a 2:1 transformer with an isolated primary and secondary? No. It is a pair of 1:1 transformers on a single core. I can make it work equally well by making the two transformers on separate cores. I can also make it with a pair of equal length coaxial cables. Both of these realisations defeat his claim that it is a 2:1 transformer. But at the same time, neither of them answer his claim that it is impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers. 2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? This isn't even a gray area. We're making a BALUN, in other words a transformer that has an UNbalanced port and a BALanced port, and in this case fully meeting the definition of a current balun. If we were to accept the above statement, then we would have no choice except to conclude that in no circumstances could we make a BALUN with transmission line transformers because in all cases of BALUNs one port is fed unbalanced. Making transmission line transformers is not difficult, although Tom is making it appear as though it's some sort of great mustery. For a length of transmission line that is sufficiently short with respect to wavelength, meaning less than an eighth of a wavelength in practice, the following rules are observed: 1. The voltage across the one conductor is equal to the voltage of the other conductor, both in magnitude and in phase. 2. The current in the one conductor is equal in magnitude but oppostite in phase to the current in the other conductor. These basic understandings of transmission line transformers are well established and understood. Gary Breed brought the concept down to the essentials in: Breed, Gary, "Transmission Line Transformer Basics," Applied Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60. It all comes down to a difference between what is known by way of established theory and practice versus trying to convince people that everything we know is wrong. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Senior Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks "Ian White GM3SEK" wrote in message ... Chris Trask wrote: It's not a matter of whether I disagree with him or not. It's a matter of him standing on a cybersoapbox and declaring to the world in numerous ways that such a thing cannot work and that only his analysis of how it can and cannot work is valid. He can't deny that he claimed that it was impossible, so now he has to prove that the solution cannot possibly work the way that he knows that it cannot work. Whatever. Please skip the personal rhetoric, and tell us how you respond to his two main technical points about your transformer: 1. That it is simply a 2:1 transformer with an isolated primary and secondary? 2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
#3
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I left out the word "current". My balun is a proper current balun as
it meets the formal definition, which is that it maintains currents at the output terminals that are equal in magnitude and opposite in phase regardless of potentials at the output terminals with respect to the ground connection on the unbalanced side. You can find this definition in less strict form in the ARRL handbook, such as 1991 pages 16.8-16.9. I agree.It just isn't a transmission line balun, nor an optimum design for most applications. The single core Guanella 4:1 current balun meets this definition but only for floating loads. Anything other than that and the two transformers need to be on separate cores. I agree again. That's what I've been saying all along. There we have it. Problem solved except for calling transmission lines transformers, and transformers transmission lines. 73 Tom |
#4
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However, with no electrical connection (transmission line) existing
between primary/secondary, and the voltage and current only conducted between these windings by a magnetic flux--I CAN'T see how a "true" balun can be argued, clearly--as opposed to "rf transformer." But, I am giving this thought--as I am sure are others... I never thought about the humble "balun"/"rf transformer" in some of these ways before--possibly I am not alone... either and anyway, I enjoy the thinking you have established here... Aw comen on now John. Every single link coupled transformer from the 1900's to today works on the principle, as do link coupled tuners or matching systems. Many solid state amplifiers, as amatter of fact MOST HF solid state amps use a primary/secondary transformer to couple unbalanced loads to the PA transistors balanced source. As a matter of fact many use a similar circuit as this "novel invention". The ALM-500 for example used series secondarys for a period of time, as did Henry amps. I had a push-pull 810 amplifier that used the same system to drive the grids of the triodes in 1964 or 65. Using a transformer with interleaved or coaxial windings is about as new as the first power transmission with AC power. The only thing new or novel about Chris' "invention" is he has redefined transmission line to include flux-coupled windings that do not convey energy via TEM (transverse electiomagnetic) waves like the normal transmission line we use. Making up a new definition is not the same as producing a new or novel invention. This is almost like the new invention call Fractal antennas or E-H antennas that don't use "old" technology! 73 Tom |
#5
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John's big thing in life is to do an internet search on any current subject,
he then regurgitates it so he can appear to have something to add to the discussion. "W8JI" wrote in message oups.com... Aw comen on now John. Every single link coupled transformer from the 1900's to today works on the principle, as do link coupled tuners or matching systems. |
#6
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W8JI wrote:
Making up a new definition is not the same as producing a new or novel invention. This is almost like the new invention call Fractal antennas or E-H antennas that don't use "old" technology! This thread has got me wondering if "Ruthroff" balun is the same as "voltage" balun and if "Guanella" balun is the same as "current" balun, as was explained to me once by a balun guru. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#7
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I just happened upon an App. note written by Philips
Semiconductors (ECO6907) titled "Design of HF wideband power transformers" which states for both 4:1 and 9:1 transmission line transformers that they CAN be wound on a single core if desired for certain conditions (see sections 6.3, 6.4 and 6.6). http://www.semiconductors.philips.co...es/ECO6907.pdf 73, Larry, W0QE |
#8
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![]() "Larry Benko" wrote in message ... I just happened upon an App. note written by Philips Semiconductors (ECO6907) titled "Design of HF wideband power transformers" which states for both 4:1 and 9:1 transmission line transformers that they CAN be wound on a single core if desired for certain conditions (see sections 6.3, 6.4 and 6.6). http://www.semiconductors.philips.co...es/ECO6907.pdf 73, Larry, W0QE And, that comes in TWO parts. ECO6907 and ECO 7213. BOTH wonderful resources, and both apply to the discussion here. (They DO call them "conventional transformers" and not Baluns.) W4ZCB |
#9
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The article calls all of the devices transformers, not "conventional
transformers" including the phase inverter that is a TLT. |
#10
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![]() "KD5NWA" wrote in message oups.com... The article calls all of the devices transformers, not "conventional transformers" including the phase inverter that is a TLT. Actually, if you'll take a read of part 2 of the application note ECO6907, (ECO7213, which I referenced) It specifically states that part 1 was devoted entirely to the design of *transmission line transformers*, which had the advantage of the widest possible bandwidth, but several disadvantages as well. Therefore, part 2 considers the possibility of applying a *conventional transformer* if those constraints were undesireable. Sheeeeeeeeesh! W4ZCB |
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