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A Single-Core 4:1 Current Balun
In recent days on the QRP-L mailing list, the following remarks were
made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
On Wed, 22 Jun 2005 13:40:26 GMT, "Chris Trask"
wrote: The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. Hi Chris, It looks like you may both have problems. Tom is quoted here, infrequently, but sparingly so where what "he says" is often clipped to fit the argument in rebuttal. It would be far simpler to completely remove what "he says" and present your own offering for support or examination. 73's Richard Clark, KB7QHC |
Chris:
This looks like a new idea to me. I will wind a couple/few and play with them. If they perform as you state--this is revolutionary. Now be prepared for attacks from the ego freaks and religious radio zealots... ESPECIALLY if you are correct... grin John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
That being the case, here are the postings where the quotes came from.
The first quote: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." can be found in it's entirety in the QRP-L archives at: http://mailman.qth.net/pipermail/qrp...12/020884.html showing that it is not taken out of context, and the second quote: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " can also be found in it's entirety in the QRP-L archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html again showing that it is not taken out of context. With very little effort, anyone can go through this thread (as well as the spin-off threads). 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 ----- Original Message ----- From: "Richard Clark" Newsgroups: rec.radio.amateur.antenna Sent: Wednesday, June 22, 2005 11:03 AM Subject: A Single-Core 4:1 Current Balun On Wed, 22 Jun 2005 13:40:26 GMT, "Chris Trask" wrote: The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. Hi Chris, It looks like you may both have problems. Tom is quoted here, infrequently, but sparingly so where what "he says" is often clipped to fit the argument in rebuttal. It would be far simpler to completely remove what "he says" and present your own offering for support or examination. 73's Richard Clark, KB7QHC |
On Wed, 22 Jun 2005 20:15:44 GMT, "Chris Trask"
wrote: again showing that it is not taken out of context. With very little effort, anyone can go through this thread (as well as the spin-off threads). Hi Chris, And if I wanted a refinement of what Tom said, does he get the same chance at dialog as you are seeking? Too often this turns to one interpreting for Tom (me or you). Again, you have an issue you wish to present, that's fine, if you want a debate judged, it needs more than one wrestler. Strip out the controversy of he-said-she-said and cut to the heart of what you have to offer. For one, I notice you say you have an improved BalUn. To me it looks slightly blighted irrespective of what Tom may have to say (and I certainly don't count him as an authority on the topic). 73's Richard Clark, KB7QHC |
"John Smith" wrote:
This looks like a new idea to me. I will wind a couple/few and play with them. If they perform as you state--this is revolutionary. Now be prepared for attacks from the ego freaks and religious radio zealots... ESPECIALLY if you are correct... grin John John, Thank you. I went looking through the extensive literature that I have here before sitting down and coming up with this. After it was all modeled, prototyped, and tested I could only wondered why I had not seen something like this earlier. I've modeled this as ideal transformers, real-world transformers (with losses and parasitics), ideal transmission lines, and lossy transmission lines and it comes out the same, with minor variations of course. I prototyped it with short coaxial cables as I did in order to minimse the parasitics and show that the models and the concept were basically valid. I'm already catching some flak, but so far it's mostly pointless dribble and obfuscation. You wouldn't believe some of the nonsense that I've been seeing. One person claims that in order to use ferrite properly with coaxial cables to make them appear shorter the ferrite has to be inside the cable between the outer braid and the centre conductor. He was immediately slam-dunked into the kill filter. 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 "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
A very interesting analysis of this design can be found at:
http://www.w8ji.com/balun_single_core_41_analysis.htm .... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Be sure to print it out as it changes almost daily. Very strange,
indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Chris:
You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Tom is absolutely desparate to prove to the world that you cannot under
any circumstances make a 4:1 current balun on a single core. So, he tests the single core Guanella balun with the usual test for a current balun (short the outputs to gound one at a time and see if the input return loss changes) knowing fully well that the Guanella 4:1 current balun on a single core will only work with floating loads. He is now equally desparate to prove that since nobody but he understands transmission line transformers it is impossible for anyone else to understand or apply them. He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. He's truly amazing, and he is mad as hell. He claims that it is absolutely impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers (of any kind whatsoever), while the Guanelle 4:1 current balun has a pair of 1:1 transformers on a single core right in front of him. He also makes numerous other outrageous claims that defy all manner of electronics theory. Here are some of his more memorable quotes along with the URLs for the QRP-L archives so you can see that he is not taken out of context, contrary to what he says: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." which in the archives at: http://mailman.qth.net/pipermail/qrp...12/020884.html This is a good one: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " which in the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and the following: "It is physically impossible to build a transmission line current balun other than 1:1 on a single core when the windings have mutual coupling through the core." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021442.html as well as: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. You can find it in voltage maps of the balun." which is the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and additionally: "It is quite possible to build any reasonable ratio of conventional transformer (as long as it is the square of turns ratio) on a single core. It is quite impossible to build a current balun of any ratio other than 1:1 using multiple transmission line transformers on a single core unless flux leakage between transmission lines is terrible." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021408.html as well as: "It impossible to build anything but a 1:1 ratio current balun when multiple transmission line transformers are placed on a single core. The voltage map shows that, as does the basic electrical rule of current baluns that all currents in all windings must sum to zero under all load balance conditions." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021416.html There is no room for ambiguity here. As you can see, he is making unsubstantiated claims of "it is impossible" and "it is well established" that have no basis in fact. The problem here is really that I solved the problem of the single-core 4:1 current balun and he is mad as hell because in his world such a thing cannot possibly exist. So, he makes up additional new electronics theories to prove that everything you 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 "John Smith" wrote in message ... Chris: You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Chris:
I see. It is interesting reading anyway, thanks. Warmest regards, John "Chris Trask" wrote in message link.net... Tom is absolutely desparate to prove to the world that you cannot under any circumstances make a 4:1 current balun on a single core. So, he tests the single core Guanella balun with the usual test for a current balun (short the outputs to gound one at a time and see if the input return loss changes) knowing fully well that the Guanella 4:1 current balun on a single core will only work with floating loads. He is now equally desparate to prove that since nobody but he understands transmission line transformers it is impossible for anyone else to understand or apply them. He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. He's truly amazing, and he is mad as hell. He claims that it is absolutely impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers (of any kind whatsoever), while the Guanelle 4:1 current balun has a pair of 1:1 transformers on a single core right in front of him. He also makes numerous other outrageous claims that defy all manner of electronics theory. Here are some of his more memorable quotes along with the URLs for the QRP-L archives so you can see that he is not taken out of context, contrary to what he says: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." which in the archives at: http://mailman.qth.net/pipermail/qrp...12/020884.html This is a good one: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " which in the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and the following: "It is physically impossible to build a transmission line current balun other than 1:1 on a single core when the windings have mutual coupling through the core." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021442.html as well as: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. You can find it in voltage maps of the balun." which is the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and additionally: "It is quite possible to build any reasonable ratio of conventional transformer (as long as it is the square of turns ratio) on a single core. It is quite impossible to build a current balun of any ratio other than 1:1 using multiple transmission line transformers on a single core unless flux leakage between transmission lines is terrible." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021408.html as well as: "It impossible to build anything but a 1:1 ratio current balun when multiple transmission line transformers are placed on a single core. The voltage map shows that, as does the basic electrical rule of current baluns that all currents in all windings must sum to zero under all load balance conditions." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021416.html There is no room for ambiguity here. As you can see, he is making unsubstantiated claims of "it is impossible" and "it is well established" that have no basis in fact. The problem here is really that I solved the problem of the single-core 4:1 current balun and he is mad as hell because in his world such a thing cannot possibly exist. So, he makes up additional new electronics theories to prove that everything you 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 "John Smith" wrote in message ... Chris: You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
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. Actually, I sort of like all of the visibility he's giving me. More people are learning that I have solved the problem because of him broadcasting it and trying desperately to dismiss it than would ever know if I had just put it on my web page and not said anything. Free advertising. I also owe it to him for inspiring me to solve the problem. If he hadn't made such outrageous statements on the QRP-L list I might never have bothered to look into the problem and learn that nobody had yet solved it, or at least solved it and made the solution known. You never know how and when opportunities like this are going to be dropped in your lap. And sometimes they come from the most unexpected places. Trick is in recognizing the opportunity and then solving it. If people were to listen to him, the problem would never be solved because according to him it is impossible to make such a thing. I've got three of them on my bench right now made three different ways, and they all work just fine despite the fact that he says they can't. The low frequency 3dB point is around 600kHz and the high frequency 3dB point is beyond 500MHz. Not bad for a couple of hours of work and a few spare parts from other projects. 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: You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Chris:
Well, your design certainly started me thinking. So, I began winding... on a single core--of course... I am NOT claiming this is unique, but it works better than the design you presented, at least, ON my sw receiver... .... take a look at it he http://blake.prohosting.com/mailguy2/balun2.JPG Warmest regards, John "Chris Trask" wrote in message link.net... Tom is absolutely desparate to prove to the world that you cannot under any circumstances make a 4:1 current balun on a single core. So, he tests the single core Guanella balun with the usual test for a current balun (short the outputs to gound one at a time and see if the input return loss changes) knowing fully well that the Guanella 4:1 current balun on a single core will only work with floating loads. He is now equally desparate to prove that since nobody but he understands transmission line transformers it is impossible for anyone else to understand or apply them. He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. He's truly amazing, and he is mad as hell. He claims that it is absolutely impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers (of any kind whatsoever), while the Guanelle 4:1 current balun has a pair of 1:1 transformers on a single core right in front of him. He also makes numerous other outrageous claims that defy all manner of electronics theory. Here are some of his more memorable quotes along with the URLs for the QRP-L archives so you can see that he is not taken out of context, contrary to what he says: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." which in the archives at: http://mailman.qth.net/pipermail/qrp...12/020884.html This is a good one: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " which in the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and the following: "It is physically impossible to build a transmission line current balun other than 1:1 on a single core when the windings have mutual coupling through the core." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021442.html as well as: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. You can find it in voltage maps of the balun." which is the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and additionally: "It is quite possible to build any reasonable ratio of conventional transformer (as long as it is the square of turns ratio) on a single core. It is quite impossible to build a current balun of any ratio other than 1:1 using multiple transmission line transformers on a single core unless flux leakage between transmission lines is terrible." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021408.html as well as: "It impossible to build anything but a 1:1 ratio current balun when multiple transmission line transformers are placed on a single core. The voltage map shows that, as does the basic electrical rule of current baluns that all currents in all windings must sum to zero under all load balance conditions." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021416.html There is no room for ambiguity here. As you can see, he is making unsubstantiated claims of "it is impossible" and "it is well established" that have no basis in fact. The problem here is really that I solved the problem of the single-core 4:1 current balun and he is mad as hell because in his world such a thing cannot possibly exist. So, he makes up additional new electronics theories to prove that everything you 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 "John Smith" wrote in message ... Chris: You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
On Mon, 27 Jun 2005 05:01:07 GMT, "Chris Trask"
wrote: He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. Hi Chris, Now, given that a "transmission line transformer," as distinct from a conventional transformer built using transmission lines, does not support flux in the ferrite; how is it that the ferrite makes the line appear longer? Second, if this were to occur (through the design of a "transmission line transformer" that was a voltage BalUn); what is the advantage of longer lines? 73's Richard Clark, KB7QHC |
On Mon, 27 Jun 2005 05:16:08 GMT, "Chris Trask"
wrote: The low frequency 3dB point is around 600kHz and the high frequency 3dB point is beyond 500MHz. Hi Chris, If this relates in some way to your published return loss characteristic, then I have to offer that it is hardly representative of the best of BalUns to offer. Sevick offers at least half a dozen with scads less loss and operating flat to within less than a fraction of a dB. Now by your tying in an implicit BW from 600KHz to 500MHz, this comes too close to brightening your teeth and improving your sex life. Within 3dB? Given your design, and it being voltage based, supporting flux through currents driving the core, 3dB would be a hell of a dummy load and hardly a crowning achievement. 73's Richard Clark, KB7QHC |
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 |
Please don't consider Chris as speaking for me, or accurately
presenting everything I said. We all know how easy it is to lift selective portions of long exchanges and make things sound any way we like. The original topic was Sevik's 4:1 balun on a single core, where that balun is made up of two 1:1 ratio choke baluns with parallel inputs and series outputs. The imputs are excited in a transmission line mode (differentially) and the outputs in series. The balun cores provide only ground isolation through common mode impedance. I have a similar balun built by MFJ, and it has terrible balance. It actually is an offset voltage voltage balun. Early on I specifically excluded transformer-type baluns. I think the problem is Chris thinks we can feed a transmission line end-to-end on a single conductor and contain energy within the line area. As far as I see, there is nothing causing the line to operate in a TEM mode, but it behaves only as a simple 1:1 transformer. I beleive this is at the root of the poor efficiency and poor SWR bandwidth of Chris' "balun". The bandwidth problem would be caused because a transmission line in TEM mode would have distributed capacitance cancelling series inductance of the leads, a transformer winding does not. This also gives rise to the distributed capacitance tending to pull the load side to the voltage balance of the source winding, causing a problem with high frequency balance. The isolation transformer method has the advantage of much better low frequency isolation and allowing a single core, but falls on its face for SWR response, power handling for a given core size, and high frequency balance and common mode isolation. I think the real argument or disagreement is if the lines in a parallel or coaxial wound primary and secondary like Chris used are in TEM mode, or simply acting as a transformer. My contention is it is a transformer, and those who think any two parallel or concentric conductors when fed start-to-finish or tend-to-end on one conductor forces a TEM mode are not viewing the system correctly. It will be interesting to see what others think. I have a partial analysis on my web site in a 4:1 balun analysis , and I'll be adding more information to that as time permits. Please, just the technical facts. I'll speak for myself. 73 Tom |
By the way, the reason I think this issue is important is Sevik claims
two transmission line baluns (excited as real transmission lines, not as isolation transformers) makes a good single core current balun. Not only are people doing that for themselves, commercial people (like MFJ) have copied the idea. They then advertise a single corev TL 4:1 balun as a "4:1 current balun" to consumers. It seems once something gets into print, it is accepted as fact even when incorrect. I'd like to clarify Sevik used transmission line mode, not transformer mode coupling, in his single core 4:1 current balun. My contention is it is impossible to build a 4:1 current balun on a single core unless it is a primary-secondary isolation transformer, and an isolation transformer would be a very limited performance balun compared to a properly constructed transmission line balun. 73 Tom |
Chris Trask wrote:
Tom is absolutely desparate to prove to the world that you cannot under any circumstances make a 4:1 current balun on a single core. Personalities aside, 4:1 single core Guanella baluns are covered on pages 9-13 to 9-21 in "Transmission Line Transformers", by Jerry Sevick. -- 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! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
W8JI wrote:
I'd like to clarify Sevik used transmission line mode, not transformer mode coupling, in his single core 4:1 current balun. My contention is it is impossible to build a 4:1 current balun on a single core unless it is a primary-secondary isolation transformer, and an isolation transformer would be a very limited performance balun compared to a properly constructed transmission line balun. Just so we know which Sevik design you are talking about, is it Fig 9-8(B) of "Transmission Line Transformers"? -- 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! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Page 24 of third printing 2002.
Single core Guanella balun. |
It seems once something gets into print, it is accepted as fact even when incorrect. ================================ Especially on this newsgroup. At least until it is refuted. How can one distinguish between fact and fiction? The gift of the gab and length of diatribe appear to predominate. |
John,
Yes, that's very nice. A pair of trifilar windings on a single core. That's a variation of a 1:1 transmission line balun that I found in a textbook. I've put the schematic and photo in a PDF file on my web page at: http://www.home.earthlink.net/~chris...M1to1Balun.PDF I'm qite certain that the two dots connecting the outer conductors to the shield box are in error as in the photo the outer insulating jacket is not broken. And those connections do not make sense, at least not immediately, as the voltages and currents at that point are dissimilar. Also, there should only be the one ground connection at the near end of the second cable. Seems to me that you could use this approach to make a nice, inexpensive and lightwieght balun with just two 4-foot pieces of coax. I would certainly like someone to try that and let us know how well it works. 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, your design certainly started me thinking. So, I began winding... on a single core--of course... I am NOT claiming this is unique, but it works better than the design you presented, at least, ON my sw receiver... ... take a look at it he http://blake.prohosting.com/mailguy2/balun2.JPG Warmest regards, John "Chris Trask" wrote in message link.net... Tom is absolutely desparate to prove to the world that you cannot under any circumstances make a 4:1 current balun on a single core. So, he tests the single core Guanella balun with the usual test for a current balun (short the outputs to gound one at a time and see if the input return loss changes) knowing fully well that the Guanella 4:1 current balun on a single core will only work with floating loads. He is now equally desparate to prove that since nobody but he understands transmission line transformers it is impossible for anyone else to understand or apply them. He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. He's truly amazing, and he is mad as hell. He claims that it is absolutely impossible to make a 4:1 current balun on a single core with a pair of 1:1 transformers (of any kind whatsoever), while the Guanelle 4:1 current balun has a pair of 1:1 transformers on a single core right in front of him. He also makes numerous other outrageous claims that defy all manner of electronics theory. Here are some of his more memorable quotes along with the URLs for the QRP-L archives so you can see that he is not taken out of context, contrary to what he says: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." which in the archives at: http://mailman.qth.net/pipermail/qrp...12/020884.html This is a good one: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " which in the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and the following: "It is physically impossible to build a transmission line current balun other than 1:1 on a single core when the windings have mutual coupling through the core." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021442.html as well as: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. You can find it in voltage maps of the balun." which is the archives at: http://mailman.qth.net/pipermail/qrp...21/021331.html and additionally: "It is quite possible to build any reasonable ratio of conventional transformer (as long as it is the square of turns ratio) on a single core. It is quite impossible to build a current balun of any ratio other than 1:1 using multiple transmission line transformers on a single core unless flux leakage between transmission lines is terrible." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021408.html as well as: "It impossible to build anything but a 1:1 ratio current balun when multiple transmission line transformers are placed on a single core. The voltage map shows that, as does the basic electrical rule of current baluns that all currents in all windings must sum to zero under all load balance conditions." which is in the archives at: http://mailman.qth.net/pipermail/qrp...22/021416.html There is no room for ambiguity here. As you can see, he is making unsubstantiated claims of "it is impossible" and "it is well established" that have no basis in fact. The problem here is really that I solved the problem of the single-core 4:1 current balun and he is mad as hell because in his world such a thing cannot possibly exist. So, he makes up additional new electronics theories to prove that everything you 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 "John Smith" wrote in message ... Chris: You do not agree with any of his analysis? You do not think this is more of an isolation transformer than a balun? If not, how do you claim a "transmission line" quality/effect to it? And, you did notice an insertion loss from this "device", didn't you? John "Chris Trask" wrote in message ink.net... Be sure to print it out as it changes almost daily. Very strange, indeed. -- 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 ... A very interesting analysis of this design can be found at: http://www.w8ji.com/balun_single_core_41_analysis.htm ... for those who have not yet seen it. John "Chris Trask" wrote in message ink.net... In recent days on the QRP-L mailing list, the following remarks were made by Tom Rauch, W8JI regarding the design of 4:1 current baluns: "...it is impossible to build a 4:1 ratio current balun that uses two 1:1 baluns on a single core." and: "It's well established any balun made up of series / parallel transmission lines requires different voltages from the start to finish of each transmission line. " I have devised and modeled a 4:1 current balun using two 1:1 baluns on a single core, and have tested a fully functional prototype. The design can be built without any core, if so desired. The full disclosure of this design with all theory, references, and test results can be obtained from my web page at: http://www.home.earthlink.net/~chris...k4to1Balun.pdf The design proves beyond all reasonable doubt that the above statements to the contrary are, to put it mildly, gravely in error. 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 |
Reg Edwards wrote:
How can one distinguish between fact and fiction? The Scientific Method comes to mind. -- 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 =--- |
Now, given that a "transmission line transformer," as distinct from a conventional transformer built using transmission lines, does not support flux in the ferrite; how is it that the ferrite makes the line appear longer? The ferrite makes the line look longer by way of it's permeability, but that's obvious and I think I'm not understanding your question correctly. Dye and Granberg cover that in their Motorola application notes as well as in the section on TLTs in their book "Radio Frequency Transistors: Principles and Practical Applications." They briefly mention in the book that the coupling takes place in the magnetic material only at low frequencies. This effectively makes the line(s)look longer as you are no longer functioning as a TLT but instead as a flux-coupled transformer, and the line length is now a function of the physical length of the conductors and the permeability of the material. In practice a thumbnail approximation is generally: L' = L x sqrt(u) Second, if this were to occur (through the design of a "transmission line transformer" that was a voltage BalUn); what is the advantage of longer lines? It's a matter of what's practical. If you were to use very short lines along with a high permeability material such as Fair-Rite 73, you may encouter a region where the lines are too short to couple properly and the magnetic material is well above the ferroresonance frequency. And even when you do get into the flux-coupling môde, you still need to have sufficient line in order to obtain decent coupling at lower frequencies. So, you have to balance the two (line length and magnetic material) in order to obtain a wideband transformer that has consistent performance over the desired frequency range. I hope I've covered everything here adequately. 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 "Richard Clark" wrote in message ... On Mon, 27 Jun 2005 05:01:07 GMT, "Chris Trask" wrote: He also fails completely in understanding that the ferrite used in transmission line transformers is to improve the low frequency end by making the transmission line appear longer. Hi Chris, Now, given that a "transmission line transformer," as distinct from a conventional transformer built using transmission lines, does not support flux in the ferrite; how is it that the ferrite makes the line appear longer? Second, if this were to occur (through the design of a "transmission line transformer" that was a voltage BalUn); what is the advantage of longer lines? 73's Richard Clark, KB7QHC |
Yes, as well as elsewhere.
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 "Cecil Moore" wrote in message ... Chris Trask wrote: Tom is absolutely desparate to prove to the world that you cannot under any circumstances make a 4:1 current balun on a single core. Personalities aside, 4:1 single core Guanella baluns are covered on pages 9-13 to 9-21 in "Transmission Line Transformers", by Jerry Sevick. -- 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! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Whoa, let's reign back here a bit. The test was still for a 200-ohm
load, but it was made asymmetric (150-ohms and 50-ohms) in order to accomodate the 50-ohm network analyzer. The 6dB loss is a result of the voltage at the test port being Vin/2, but the voltage at the other output port with the 150-ohm resistor is 3Vin/2, so there is no excessive loss through the balun. In actuality, there is less than 0.1dB of power loss in the prototype that I made. The test was made to determine if the balance was correct. 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 "Richard Clark" wrote in message ... On Mon, 27 Jun 2005 05:16:08 GMT, "Chris Trask" wrote: The low frequency 3dB point is around 600kHz and the high frequency 3dB point is beyond 500MHz. Hi Chris, If this relates in some way to your published return loss characteristic, then I have to offer that it is hardly representative of the best of BalUns to offer. Sevick offers at least half a dozen with scads less loss and operating flat to within less than a fraction of a dB. Now by your tying in an implicit BW from 600KHz to 500MHz, this comes too close to brightening your teeth and improving your sex life. Within 3dB? Given your design, and it being voltage based, supporting flux through currents driving the core, 3dB would be a hell of a dummy load and hardly a crowning achievement. 73's Richard Clark, KB7QHC |
W8JI wrote:
Page 24 of third printing 2002. Single core Guanella balun. Unfortunately, I don't have that edition. Is it four windings? 1---/////////---2 3---/////////---4 5---/////////---6 7---/////////---8 with (1 to 5) and (3 to 7) as the unbalanced input, (4 to 6) tied together, and (2) and (8) as the balanced output? -- 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 =--- |
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 |
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 |
On Mon, 27 Jun 2005 15:13:05 GMT, "Chris Trask"
wrote: Whoa, let's reign back here a bit. The test was still for a 200-ohm load, but it was made asymmetric (150-ohms and 50-ohms) in order to accomodate the 50-ohm network analyzer. Hi Chris, You state you have several of these units, performing back-to-back applications would resolve what you call asymmetry. The 6dB loss is a result of the Where did the 6dB come from? I didn't notice this mentioned anywhere. Further, there is a strong 2dB/Octave frequency characteristic that is not explained as an issue of symmetry. voltage at the test port being Vin/2, but the voltage at the other output port with the 150-ohm resistor is 3Vin/2, so there is no excessive loss through the balun. I don't know where this Vin/2 comes from. What is this divisor you've injected into the discussion? As you offer it has no obvious correlation to frequency, it stands that that same 2dB/Octave roll-off is part and parcel to the unit's loss. In actuality, there is less than 0.1dB of power loss in the prototype that I made. No where in your paper do you show the method to determine this, nor do you reveal such a figure. The test was made to determine if the balance was correct. The word "balance" occurs only once in your paper, and that as an unsupported declaration. I see no work nor data to offer it as a conclusion. 73's Richard Clark, KB7QHC |
On Mon, 27 Jun 2005 15:05:18 GMT, "Chris Trask"
wrote: how is it that the ferrite makes the line appear longer? The ferrite makes the line look longer by way of it's permeability Hi Chris, Conventionally, this is not an asset of BalUns. In fact, employing permeability risks saturation, and saturation risks catastrophic failure. The paragraphs that followed (not quoted here) relate to the operation of a conventional transformer. Second, if this were to occur (through the design of a "transmission line transformer" that was a voltage BalUn); what is the advantage of longer lines? It's a matter of what's practical. Practical? This does not prove an advantage, it is a non-sequitur. If you were to use very short lines along with a high permeability material such as Fair-Rite 73, you may encouter a region where the lines are too short to couple properly and the magnetic material is well above the ferroresonance frequency. And even when you do get into the flux-coupling môde, you still need to have sufficient line in order to obtain decent coupling at lower frequencies. So, you have to balance the two (line length and magnetic material) in order to obtain a wideband transformer that has consistent performance over the desired frequency range. Most of this presumes a conventional transformer design. Your data supports the results encountered from a conventional transformer design. The risks of using a conventional transformer design are legion. I see nothing that suggests this novel design is superior to a Transmission Line Transformer (AKA Current BalUn). 73's Richard Clark, KB7QHC |
Chris Trask wrote:
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. If it were a mains or an audio transformer with four identical windings, two primaries in parallel and two secondaries in series, most people wouldn't hesitate to call that a "2:1" (voltage ratio) transformer. You could also choose to call it "a pair of 1:1 transformers on a single core" and that would also be valid, though I don't believe that would be most people's preferred description. The same output voltages can *also* be obtained by a different method, by appropriately wiring two completely separate 1:1 transformers, but that doesn't affect the way we should think about the transformer on a single core. 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. Agreed. 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. I was talking about TLT's, not baluns. Some baluns are TLT but others are not. 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. Sorry, but it all seems to come down to the definitions of "current balun" and "transmission line transformer" that one chooses to adopt. Rather than referencing those definitions, please can you quote them here, in full? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
Ian:
Yes, you inject a VERY GOOD point here--I realize my "definitions" are a bit blurry. And, indeed, scanning the internet suggests there are some others out there suffering the same. What can we all agree are proper definitions to balun, "rf transformer", etc... I admit I have not ever set up a solid foundation of knowledge here--just used ideas, plans, etc which others have made available... and referred to them by the names given... this leaves me at a loss while I investigate. John "Ian White GM3SEK" wrote in message ... Chris Trask wrote: 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. If it were a mains or an audio transformer with four identical windings, two primaries in parallel and two secondaries in series, most people wouldn't hesitate to call that a "2:1" (voltage ratio) transformer. You could also choose to call it "a pair of 1:1 transformers on a single core" and that would also be valid, though I don't believe that would be most people's preferred description. The same output voltages can *also* be obtained by a different method, by appropriately wiring two completely separate 1:1 transformers, but that doesn't affect the way we should think about the transformer on a single core. 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. Agreed. 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. I was talking about TLT's, not baluns. Some baluns are TLT but others are not. 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. Sorry, but it all seems to come down to the definitions of "current balun" and "transmission line transformer" that one chooses to adopt. Rather than referencing those definitions, please can you quote them here, in full? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
Ian:
Here is a rather good paper on TLT's, this should be a definition acceptable to most... http://www.highfrequencyelectronics....204_Sevick.pdf John "Ian White GM3SEK" wrote in message ... Chris Trask wrote: 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. If it were a mains or an audio transformer with four identical windings, two primaries in parallel and two secondaries in series, most people wouldn't hesitate to call that a "2:1" (voltage ratio) transformer. You could also choose to call it "a pair of 1:1 transformers on a single core" and that would also be valid, though I don't believe that would be most people's preferred description. The same output voltages can *also* be obtained by a different method, by appropriately wiring two completely separate 1:1 transformers, but that doesn't affect the way we should think about the transformer on a single core. 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. Agreed. 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. I was talking about TLT's, not baluns. Some baluns are TLT but others are not. 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. Sorry, but it all seems to come down to the definitions of "current balun" and "transmission line transformer" that one chooses to adopt. Rather than referencing those definitions, please can you quote them here, in full? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
Unfortunately, I don't have that edition.
Is it four windings? 1---/////////---2 3---/////////---4 5---/////////---6 7---/////////---8 with (1 to 5) and (3 to 7) as the unbalanced input, (4 to 6) tied together, and (2) and (8) as the balanced output? Yes, but they are not windings. They are parallel conductors in pairs. 1 and 3 form one pair. 5 and 7 the other. You can see a schematic at: http://www.w8ji.com/balun_single_core_41_analysis.htm under real transmisison line balun. Sevik proposes the winding can share a common core. 73 Tom |
The entire difference between Chris and I is in my opinion he built
what most of the world would call a transformer. There is no forced TEM mode excitation that I can see. Sevik clearly drew a pair of transmission lines, and that was what I was discussing (and I even exempted a primary/secondary transformer. If I take a true transmission line choke balun and remove the core, electrical line length does not change significantly. Chris in an earlier post claimed the core lengthened the electrical "line length". Also I'm assuming he didn't use 100 ohm lines, as a TL 4:1 balun requires. He used coax, which as far as I know isn't easy to make at 100 ohms. The limited SWR BW, the fact the core affects the electrical length of the "lines", the high loss (.1dB), the fact the lines don't need to be 100 ohm lines, the lack of differential mode excitaion of the start.....all point to operation like any other interleaved winding transformer including audio and some power transformers. I don't think an isolation transformer is "new art", but calling it a transmission line transformer might be new! ;-) 73 Tom |
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 |
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 |
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 |
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