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Cecil, was it you that mention a "windom balun?"
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=16722
I don't know why? But, I seem to remember you asking or something about windom baluns ... or, maybe I just have to worry about being a maroon idiot with an imagination! Darn, I just hate that reference to "purplish" though ... purple is a homosexual symbol here, at least in California, bad association yanno'? .... straight face Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 6 sep, 04:05, John Smith wrote:
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=16722 I don't know why? *But, I seem to remember you asking or something about windom baluns ... or, maybe I just have to worry about being a maroon idiot with an imagination! Darn, I just hate that reference to "purplish" though ... purple is a homosexual symbol here, at least in California, bad association yanno'? ... straight face Regards, JS Hello John, For me this is just a Guanella balun, 1:4 impedance transformation with common mode suppression. I didn't do the math to see whether common mode impedance is sufficient for OCF dipoles (to avoid feed line radiation). Regarding color use (purple/pink), that isn't limited to California only. Best regards, Wim PA3DJS www.tetech.nl without abc, PM will reach me very likely |
Cecil, was it you that mention a "windom balun?"
On 9/6/2010 1:16 AM, Wimpie wrote:
... Hello John, For me this is just a Guanella balun, 1:4 impedance transformation with common mode suppression. I didn't do the math to see whether common mode impedance is sufficient for OCF dipoles (to avoid feed line radiation). At this point, I can't even remember why the reference of "balun to windom to Cecil" holds a relationship in my mind ... I didn't pay any attention to the core material/turns/etc. of the baluns which I posted either ... just seeing if it related to what has stuck in my mind and tossed it at Cecil to see. Regarding color use (purple/pink), that isn't limited to California only. I had wondered about that! P*ssed me off when I had to give up wearing purple ... I had always let the wife "wear the pink" in the family. lol Best regards, Wim PA3DJS www.tetech.nl without abc, PM will reach me very likely Regards, JS |
Cecil, was it you that mention a "windom balun?"
On Sep 5, 9:05*pm, John Smith wrote:
I don't know why? *But, I seem to remember you asking or something about windom baluns ... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com |
Cecil, was it you that mention a "windom balun?"
On 9/6/2010 5:08 AM, Cecil Moore wrote:
... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com I have a "weird thing" about windoms ... I just don't trust an antenna which "manipulates" RF on the feedline in "beneficial" ways and has a religious cult following ... insane quirk of mine, really. lol Now I don't have the room ... moved again. If the wife had her way, we would move to Montana next to a favorite sister and brother ... there we would have the room! lol Regards, JS |
Cecil, was it you that mention a "windom balun?"
"John Smith" wrote in message ... On 9/6/2010 5:08 AM, Cecil Moore wrote: ... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com I have a "weird thing" about windoms ... I just don't trust an antenna which "manipulates" RF on the feedline in "beneficial" ways and has a religious cult following ... insane quirk of mine, really. lol Now I don't have the room ... moved again. If the wife had her way, we would move to Montana next to a favorite sister and brother ... there we would have the room! lol Regards, JS Just throwing in my comments on the so called Carolina Windom like Cecil described. I have one up like that and also an 80 meter dipole and triband beam up to compare signals with. Not all cases, but many times the Windom is as good or better than the other antennas. The beam does beat the Windom by about double the microvolt signals on the very long signal path. The balun I am using is suppose to be able to handle the power I am running, but around 1 kw to the antenna the 4:1 balun overheats after about 5 minuets and the swr starts going up. There is some current coming down the feedline as the choke balun 20 feet down the coax is getting warm. It does not do that with about 1200 watts going into it while connected to a dummy load. Like most any simple antenna, you throw RF at it and hope the signal goes in a direction that lets you make contacts. The antenna can be set so that it is most favorable in one or two directions, but when making contacts all around, it is difficult to change the direction of the dipole. |
Cecil, was it you that mention a "windom balun?"
On 6 sep, 14:30, John Smith wrote:
On 9/6/2010 5:08 AM, Cecil Moore wrote: ... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com I have a "weird thing" about windoms ... I just don't trust an antenna which "manipulates" RF on the feedline in "beneficial" ways and has a religious cult following ... insane quirk of mine, really. lol *Now I don't have the room ... moved again. If the wife had her way, we would move to Montana next to a favorite sister and brother ... there we would have the room! lol Regards, JS Hello John, When the feed line goes to a clean environment (for example a ground provision far from the shack feed line radiation may not be a problem, but it isn't my favorite. When the feed line goes directly to the shack (and equipment), I don't want such an antenna. When you are working NVIS on 75/80m, you don't want the vertical component as this leads to radiation under low elevation, hence stronger reception of ground based interference. In case of DX, the vertical component may help you as this may result in lower elevation of main lobe; over here we have much soil with better then average conductivity. If I would like vertical polarization, I prefer 100% of that, so no windom or OCF dipoles for me. Depending on the design, allowing vertically polarized radiation may result in worse or better VSWR. Regarding the color, many straight people wear it over here (especially in summer days), so you can't judge on color only.... Regarding the balun/transformer, you need a very good one with OCF dipoles as common mode voltage at feed point can be in the 300V range with 100W input. just some pF stray capacitance in a transformer will provoke feed line radiation. Best regards, Wim PA3DJS www.tetech.nl without abc in the address, PM will reach me. |
Cecil, was it you that mention a "windom balun?"
On 6 sep, 13:14, Wimpie wrote:
On 6 sep, 14:30, John Smith wrote: On 9/6/2010 5:08 AM, Cecil Moore wrote: ... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com I have a "weird thing" about windoms ... I just don't trust an antenna which "manipulates" RF on the feedline in "beneficial" ways and has a religious cult following ... insane quirk of mine, really. lol *Now I don't have the room ... moved again. If the wife had her way, we would move to Montana next to a favorite sister and brother ... there we would have the room! lol Regards, JS Hello John, When the feed line goes to a clean environment (for example a ground provision far from the shack feed line radiation may not be a problem, but it isn't my favorite. *When the feed line goes directly to the shack (and equipment), I don't want such an antenna. When you are working NVIS on 75/80m, you don't want the vertical component as this leads to radiation under low elevation, hence stronger reception of ground based interference. In case of DX, the vertical component may help you as this may result in lower elevation of main lobe; over here we have much soil with better then average conductivity. If I would like vertical polarization, I prefer 100% of that, so no windom or OCF dipoles for me. Depending on the design, allowing vertically polarized radiation may result in worse or better VSWR. Regarding the color, many straight people wear it over here (especially in summer days), so you can't judge on color only.... Regarding the balun/transformer, you need a very good one with OCF dipoles as common mode voltage at feed point can be in the 300V range with 100W input. just some pF *stray capacitance in a transformer will provoke feed line radiation. Best regards, Wim PA3DJSwww.tetech.nl without abc in the address, PM will reach me.- Ocultar texto de la cita - - Mostrar texto de la cita - Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel |
Cecil, was it you that mention a "windom balun?"
On 9/9/2010 7:26 AM, lu6etj wrote:
... Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel Yes, I see your point, and agree. I have never ran a windom or experimented with it, so obviously, others are much more knowledgeable with them. However, logic tells me they would be one easily justifiable situation to use a voltage balun ... the CM currents being looked at separately ... the balun must have a definite and pronounced effect on pattern with this particular antenna. Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 9/9/2010 7:26 AM, lu6etj wrote:
Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel Before beginning a discussion about what constitutes a balanced load and what doesn't, how about answering these questions? 1. What is "balance"? 2. What defines a "balanced" feedline? 3. What are the properties of a "balanced" load? 4. How can you tell when a line, load, or transmitter is "balanced"? 5. What's the big deal about being "balanced", anyway? And finally, How does a balun achieve "balance"? Roy Lewallen, W7EL |
Cecil, was it you that mention a "windom balun?"
On 9/9/2010 7:26 AM, lu6etj wrote:
... Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel Tell 'em one thing "balance" means is if you have a funky antenna depending on feedline currents/radiation/etc. you don't start chucking a bunch of stuff in the feedline without expecting patterns to change ... Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 9 sep, 15:48, Roy Lewallen wrote:
On 9/9/2010 7:26 AM, lu6etj wrote: Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel Before beginning a discussion about what constitutes a balanced load and what doesn't, how about answering these questions? 1. What is "balance"? 2. What defines a "balanced" feedline? 3. What are the properties of a "balanced" load? 4. How can you tell when a line, load, or transmitter is "balanced"? 5. What's the big deal about being "balanced", anyway? And finally, How does a balun achieve "balance"? Roy Lewallen, W7EL Hello Roy Why? that way we can end up having to define all words we use :). I learnt a two terminal balanced circuit basically have the same impedance respect to ground in its terminals, if Windom Carolina not have it, well... we have missed the "bal" part of the equation :) I recognize the other items are interesting to analize too but in diferent sense that the proper use of the term "balun" towards I pointed my little observation. Years ago I have read your very good article "Baluns: What They Do And How They Do lt" (until today I keep it safe in my computer for reference) and I believe I understand where you point to with the other good questions. For John: Dear friend I could not translate well your post, may you repeat in a little more Tarzan english for me? Miguel |
Cecil, was it you that mention a "windom balun?"
On 9/9/2010 6:50 PM, lu6etj wrote:
... For John: Dear friend I could not translate well your post, may you repeat in a little more Tarzan english for me? Miguel Miguel, I can see why. I used some good old American satire-humor ... it is OK my friend ... Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 9/9/2010 6:50 PM, lu6etj wrote:
On 9 sep, 15:48, Roy wrote: Before beginning a discussion about what constitutes a balanced load and what doesn't, how about answering these questions? 1. What is "balance"? 2. What defines a "balanced" feedline? 3. What are the properties of a "balanced" load? 4. How can you tell when a line, load, or transmitter is "balanced"? 5. What's the big deal about being "balanced", anyway? And finally, How does a balun achieve "balance"? Roy Lewallen, W7EL Hello Roy Why? that way we can end up having to define all words we use :). I learnt a two terminal balanced circuit basically have the same impedance respect to ground in its terminals, if Windom Carolina not have it, well... we have missed the "bal" part of the equation :) I recognize the other items are interesting to analize too but in diferent sense that the proper use of the term "balun" towards I pointed my little observation. Years ago I have read your very good article "Baluns: What They Do And How They Do lt" (until today I keep it safe in my computer for reference) and I believe I understand where you point to with the other good questions. For John: Dear friend I could not translate well your post, may you repeat in a little more Tarzan english for me? Miguel Suppose you connect a transmission line to a perfectly symmetrical, horizontal antenna. The antenna and feedline would be a "balanced circuit" by your definition, since the two conductors of the transmission line have equal impedances to ground. But the transmission line will radiate. Now connect one conductor of the transmission line to the center of your rig's coaxial connector, and the other conductor to the rig's chassis. (This is Fig. 2 of the article you mention, which by the way is available at http://eznec.com/Amateur/Articles/Baluns.pdf.) Is it still a "balanced circuit"? Why or why not? Or suppose you take two signal generators which are perfectly coherent (i.e., phase locked to run at exactly the same frequency) and exactly in phase with each other. Each has a 50 ohm output impedance and each produces exactly 1 volt RMS of RF when open circuited. Connect one of these to each of the terminals of the feedline instead of connecting the feedline to your transmitter. Now, -- The impedances to ground looking toward the antenna from the feedline are the same for the two feedline terminals. -- The impedances looking back toward the generators from the feedline are the the same for the two feedline terminals. -- The two feedline conductors have equal voltages and currents. -- The circuit is surely balanced by your definition. Yet the feedline will radiate. Change the generator phasing any other angle except 180 degrees, and the feedline will radiate. Only when the two generators are exactly out of phase will the line cease radiating. I call that condition "balance" for the reasons explained in the article, but it's quite different from your definition. If we're to use your definition of "balance", we have to conclude that balanced transmission lines radiate some times and some times they don't. If the system is already "balanced" when the generators are zero or, say, 90 degrees out of phase, would a balun do anything if connected between the generators and transmission line? Roy Lewallen, W7EL |
Cecil, was it you that mention a "windom balun?"
On Sun, 12 Sep 2010 09:45:02 -0700 (PDT), lu6etj
wrote: I know Wikipedia it is not authoritative but in "Balanced Line" says: "In telecommunications and professional audio, a balanced line or balanced signal pair is a transmission line consisting of two conductors of the same type, each of which have equal impedances along their lengths and equal impedances to ground and to other circuits. [1]" Hi Miguel, This reference is much better than your first citation - it mentions what the common (earth, ground, other circuits) is, which is necessary for symmetry AND balance. Your first citation merely described a loop. A loop is symmetrical within its own self, but that doesn't make it balanced. Searchiing the Web for definitions I found an interesting article in that item with similar concepts http://www.multimediamanufacturer.co...hitlock407.pdf This link gives a good introduction to common mode which is central to the problems of balance and symmetry. Can you acces to an IEEE definition? I could not. No point in that. I believe original definition perhaps was related only to noise pick up in lines, I understand your point and not oppose to it, it is a good point, perhaps we have to say "an all (o totally) balanced SYSTEM" when we want to refer to both (signal and impedance) simmetries, to eliminate ambiguities. No, that is not complete. ...... Although this is a more important issue, I insist in my original point, is it "licit" to call "balun" a device connected to two unbalanced circuits (line and antenna)?, The word properly formed is BalUn - balance/unbalanced transformer. Similarly you have a BalBal, and an UnUn so that other topologies are properly termed. Is it Carolina windom a balanced antenna? No. Here most of hams tend to call balun any toroidal transformer, with TL or traditional windings connected to any circuit! :) The term was not coined through a democratic vote - they are wrong. 73's Richard Clark, KB7QHC |
Cecil, was it you that mention a "windom balun?"
On 12 sep, 15:17, Richard Clark wrote:
On Sun, 12 Sep 2010 09:45:02 -0700 (PDT), lu6etj wrote: I know Wikipedia it is not authoritative but in "Balanced Line" says: "In telecommunications and professional audio, a balanced line or balanced signal pair is a transmission line consisting of two conductors of the same type, each of which have equal impedances along their lengths and equal impedances to ground and to other circuits. [1]" Hi Miguel, This reference is much better than your first citation - it mentions what the common (earth, ground, other circuits) is, which is necessary for symmetry AND balance. *Your first citation merely described a loop. *A loop is symmetrical within its own self, but that doesn't make it balanced. Searchiing the Web for definitions I found an interesting article in that item with similar concepts http://www.multimediamanufacturer.co...hitlock407.pdf This link gives a good introduction to common mode which is central to the problems of balance and symmetry. Can you acces to an IEEE definition? I could not. No point in that. I believe original definition perhaps was related only to noise pick up in lines, I understand your point and not oppose to it, it is a good point, perhaps we have to say "an all (o totally) balanced SYSTEM" when we want to refer to both (signal and impedance) simmetries, to eliminate ambiguities. No, that is not complete. ...... Although this is a more important issue, I insist in my original point, is it "licit" to call "balun" a device connected to two unbalanced circuits (line and antenna)?, The word properly formed is BalUn - balance/unbalanced transformer. Similarly you have a BalBal, and an UnUn so that other topologies are properly termed. Is it Carolina windom a balanced antenna? No. Here most of hams tend to call balun any toroidal transformer, with TL or traditional windings connected to any circuit! :) The term was not coined through a democratic vote - they are wrong. 73's Richard Clark, KB7QHC Hi friends Well... I believe we mostly agree for our internal use, but, there are a authoritative formal definition? because I do not found it, the only ones I found were about impedance balance, not signal implied, however it results strange to me because telegraph and phone lines crosstalks depend on current balance in wires too, then I think old engineers should be taken into account, my old RF and telephony books tends to not use balance word but "symmetry". I haven not problem with your/our concept, but have we power enough to become "The Definitors" Why "do not point in that" Richard you do not trust in IEEE guys? :) Miguel |
Cecil, was it you that mention a "windom balun?"
lu6etj wrote in
: Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel, Sometimes the language we use doesn't well describe the thing we are thinking about, and this is a case. We could well apply a meaning to balanced, that either the currents are equal in magnitude but opposite in phase; or that the voltages wrt some sensible accessible reference are equal in magnitude but opposite in phase. One does not imply the other without constraining the load characteristic. When we speak of unbalanced, we commonly think of a configuration where one side is 'grounded' and the other 'active'. The problem is that many situations in antenna systems are not purely either, they are not balanced by one or other of the meanings above, and they are not unbalanced by the meaning above. So, they need to be dealt with by the more general method of considering that there are non-zero common mode and differential voltages and currents. It would be most unlikely that a Carolina Windown would be balanced, or near to it, by any defintion. The antenna is born out of a quest to sell the disadvantage of Windom feedline radiation as a positive feature. The way I like to explain a balun is that it *facilitates* connection of a not-balanced device to a balanced device. A practical balun does not, of itself, eliminate (meaning make zero) common mode current or common mode voltage... yet we commonly use absolute words to describe its action. To a certain extent, that is saying that they are not ideal or perfect devices. Some of the rules we hams have made for baluns pretty much assure mediocre performance. Like for example what I refer to as Rule 500, that the minimum choking impedance of a current balun is ten times the differential characteristic impedance (commonly 50, hence Rule 500). I know English is not your first language, but be wary of applying the meaning of words absolutely. Owen |
Cecil, was it you that mention a "windom balun?"
On Sun, 12 Sep 2010 15:51:53 -0700 (PDT), lu6etj
wrote: Why "do not point in that" Richard you do not trust in IEEE guys? :) Sounds like you are waiting for the right pope before you go to confession. 73's Richard Clark, KB7QHC |
Cecil, was it you that mention a "windom balun?"
On 12 sep, 20:17, Owen Duffy wrote:
lu6etj wrote : Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel, Sometimes the language we use doesn't well describe the thing we are thinking about, and this is a case. We could well apply a meaning to balanced, that either the currents are equal in magnitude but opposite in phase; or that the voltages wrt some sensible accessible reference are equal in magnitude but opposite in phase. One does not imply the other without constraining the load characteristic. When we speak of unbalanced, we commonly think of a configuration where one side is 'grounded' and the other 'active'. The problem is that many situations in antenna systems are not purely either, they are not balanced by one or other of the meanings above, and they are not unbalanced by the meaning above. So, they need to be dealt with by the more general method of considering that there are non-zero common mode and differential voltages and currents. It would be most unlikely that a Carolina Windown would be balanced, or near to it, by any defintion. The antenna is born out of a quest to sell the disadvantage of Windom feedline radiation as a positive feature. The way I like to explain a balun is that it *facilitates* connection of a not-balanced device to a balanced device. A practical balun does not, of itself, eliminate (meaning make zero) common mode current or common mode voltage... yet we commonly use absolute words to describe its action. To a certain extent, that is saying that they are not ideal or perfect devices. Some of the rules we hams have made for baluns pretty much assure mediocre performance. Like for example what I refer to as Rule 500, that the minimum choking impedance of a current balun is ten times the differential characteristic impedance (commonly 50, hence Rule 500). I know English is not your first language, but be wary of applying the meaning of words absolutely. Owen Hello Owen, it is a pleasure to meet you again. Oh, yes, of course here we use our words with freedom too. I confess I call "baluncitos" (little baluns) the little toroid transformers, specially binocular ones, but in this newsgroup a lot of good people is very strict with wording and precision of terms :) then I thought it was no exaggeration from me ask whether it is correct use the term "balun" when both sides are "un", hi hi. However certainly many times in our hobby words are a true trap for novice (and not so novices), then, why not to call things with more proper name?, if a balun do not "baluning", well... call them "seudo- balun" or another similar pointer to true behaviour (as our known "pseudo-Brewster angle"). There is not a languages translation issue here Owen, you and we, in english and spanish, missuse the same words and concepts, the "thing" it is "globalized". I am far of being a purist of the tongues, but you know, we hams have misleading words, a majority of you are true experts in RF and it is difficult you can become confussed. Anyway, is not something to worry so much either, the mine It was a casual comment, blame to Roy by take us to the hard theory :D :D Greetings Miguel |
Cecil, was it you that mention a "windom balun?"
On 12 sep, 22:19, Richard Clark wrote:
On Sun, 12 Sep 2010 15:51:53 -0700 (PDT), lu6etj wrote: Why "do not point in that" Richard you do not trust in IEEE guys? :) Sounds like you are waiting for the right pope before you go to confession. 73's Richard Clark, KB7QHC Hi hi, Oh no, I am an atheist in all possibles senses of the word, but I was curious about your comment, here we call it "cosas de chismosas" (gossipy things?) :) - Miguel |
Cecil, was it you that mention a "windom balun?"
Roy Lewallen wrote in
: .... -- Be careful with the English language, in which fat chance and slim chance mean the same thing, a wise man is admired and wise guy shunned, and a bag lady and bag man are very different in ways other than just their gender. Ah yes, one's nose runs, and feet smell! Owen |
Cecil, was it you that mention a "windom balun?"
lu6etj wrote in
: .... is very strict with wording and precision of terms :) then I thought it was no exaggeration from me ask whether it is correct use the term "balun" when both sides are "un", hi hi. Perhaps the term 'common mode choke' works? I did see a raging argument someone online (eham?) just recently where parties were arguing that a 4:1 Guanella current balun could be wound on a single toroid, it was the way Guanella intended it they said, but they argued that use of two ferrite sticks for such a device was wrong. In fact, Guanella's article describes his 1:1 balun without any magnetic core material, and the 4:1 balun as a connected pair of 1:1 baluns with no (ie negligible) magnetic coupling. Yet I have seen commercial sites selling a Guanella 4:1 current balun on a single core, arguing that Sevick said it was ok in a certain context... a context that is unlikely to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they sell. That context relates to another dimension of the balanced / symmetric issue. Back to the Carolina Windom, a common explanation holds that there is common mode current on the feedline between the dipole feedpoint and the 'isolator'. The notion that common mode current exists on one side of the isolator and not on the other is an interesting one, one better explained by advertising hyperbole than radiocommunications theory. Owen |
Cecil, was it you that mention a "windom balun?"
On 9/12/2010 7:50 PM, Owen Duffy wrote:
... Yet I have seen commercial sites selling a Guanella 4:1 current balun on a single core, arguing that Sevick said it was ok in a certain context... a context that is unlikely to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they sell. That context relates to another dimension of the balanced / symmetric issue. Back to the Carolina Windom, a common explanation holds that there is common mode current on the feedline between the dipole feedpoint and the 'isolator'. The notion that common mode current exists on one side of the isolator and not on the other is an interesting one, one better explained by advertising hyperbole than radiocommunications theory. Owen The first part, above, implies that no one has ever constructed such a balun(s), one on a single core, one on a dual core, used "balanced" resistances, to serve as loads, then unbalance the loads, and observe results. I have, when constructed properly, one can be constructed on a single core. Is the dual core better? Yes ... is it possible to run the single core balun in conditions where it will fail miserably?; Yes. Is it possible to run the dual core balun in conditions where it will fail miserably?; Yes. As to the second part, I have found a properly constructed balun to be both, a choke and "impedance-transformer." Indeed, an excellent balun is optimized to take advantage of both phenomenon. And, of course, I have found and believe a 160m to 10m balun/unun is stretching things, probably beyond what one should (but, hey, you can get by with it), two baluns, a high freq and a low freq are better to cover such a span ... however, you can carry that to an extreme and optimize core material/size and windings for each specific band ... And, radio is an onion, each layer built on a preceding layer. At the core of all this is the EM transmission theory, and RF is both particles and waves ... obviously, both have great difficulty being true at the same time, so "waves of bullets" becomes the explanation ... obviously, great difficulty is going to be had in having cement solid theory in the outer layers of this onion. By the time you get to "balance" the errors are only magnified ... balance is like any balance in life ... you'll know it when you have it, and benefit from it. Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 12 sep, 23:35, Owen Duffy wrote:
Roy Lewallen wrote : ... -- Be careful with the English language, in which fat chance and slim chance mean the same thing, a wise man is admired and wise guy shunned, and a bag lady and bag man are very different in ways other than just their gender. Ah yes, one's nose runs, and feet smell! Owen I agree with you Roy in several items, when we try communicate with words and we not share the exact word meanings we end up inmersed in the Babel course. Moreover, we later build bigger ideas based in that misunderstood words, then it is not rare that at the end of the process we can not agree almost nothing. But there is a problem, explain our concepts writing in a paper it it is not ease too, any dictionary it is circular referenced, verbal or written definitions use words, then such circularity it is inherente to written language in some point we will need to point to an object, event or phenomenom and say to our partner: you see "this is a house", "that is a river". That way we learn languages when we born, linguists call them "ostensive definitions". Because that, I pointed -in early post- we could end up having to define all words we use. Here we call that process "socratic tests", because a teacher could ask and ask definitions recursively to the extent we were not able to explain even what is a mom. Also, in some point we need support us in standard accepted definitions of terms with its limitations at risk of failing to have a common language, often authoritative definitions serve to this pupose even although they are incomplete. I do not would say I hate to waste my time arguing about apparently senseless things because what to me may seems nonsense can be really important and I am not capable to see it, but I agree that comes a point where I tired and renounce (and there are much things that are really suspiciously foolish). However I recognize that drop the bone too early sometimes not conducive to resolving difficult issues, it is all a matter of "balancing" :) Thank you very much. Miguel PD: Nice examples of english meanings, when we tell: "ese es un hijo de su madre" we are not talking about kinship relationships :) |
Cecil, was it you that mention a "windom balun?"
On Sep 12, 9:50*pm, Owen Duffy wrote:
Back to the Carolina Windom, a common explanation holds that there is common mode current on the feedline between the dipole feedpoint and the 'isolator'. The notion that common mode current exists on one side of the isolator and not on the other is an interesting one, one better explained by advertising hyperbole than radiocommunications theory. As you know, common-mode RF obeys the rules of the reflection model. From an (ideal) physics standpoint, there is nothing technically wrong with having zero common mode current between the isolator and the source while having a common mode current maximum (loop) 1/4WL back toward the antenna feedpoint from the isolator. (Assume an ideal isolator with an infinite choking impedance.) Consider the following example: Source--------1/2WL coax1--------isolator-------1/2WL coax2---------- antenna feedpoint The net common-mode current on each side of the (ideal lumped) isolator must be equal to satisfy Kirchhoff. There is no technical reason why the net standing-wave common-mode current could not be zero on each side of the isolator where the isolator is causing a standing- wave current node (minimum). 1/4WL back from the isolator toward the source, there is no technical reason why the net standing-wave common- mode current could not be zero. 1/4WL forward from the isolator toward the antenna, there is no technical reason why the net standing-wave common-mode current could not be at a high (maximum-loop) value. Since it is theoretically possible, one should not dismiss it as "advertising hyperbole" without having performed the measurements to prove that particular statement applies to the Carolina Windom because of poor isolator performance, not because it violates Kirchhoff's laws. Incidentally, this is the same conceptual error that some folks have made when they reported measuring no phase shift in the current through a large air-core 75m loading coil when installed on a standing- wave antenna. Hint: Pure standing wave current has zero relative phase shift so it obviously cannot be used to measure phase shift. EZNEC confirms that fact. -- 73, Cecil, w5dxp.com |
Cecil, was it you that mention a "windom balun?"
On 9/13/2010 4:39 AM, Cecil Moore wrote:
... "Unun" is not in "The IEEE Dictionary". -- 73, Cecil, w5dxp.com Yeah, those fools haven't plagiarized someone else yet, without giving that someone else credit, give them time ... Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 9/12/2010 8:59 PM, John Smith wrote:
On 9/12/2010 7:50 PM, Owen Duffy wrote: ... Yet I have seen commercial sites selling a Guanella 4:1 current balun on a single core, arguing that Sevick said it was ok in a certain context... a context that is unlikely to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they sell. That context relates to another dimension of the balanced / symmetric issue. ... Owen The first part, above, implies that no one has ever constructed such a balun(s), one on a single core, one on a dual core, used "balanced" resistances, to serve as loads, then unbalance the loads, and observe results. I have, when constructed properly, one can be constructed on a single core. Is the dual core better? Yes ... is it possible to run the single core balun in conditions where it will fail miserably?; Yes. Is it possible to run the dual core balun in conditions where it will fail miserably?; Yes. As to the second part, I have found a properly constructed balun to be both, a choke and "impedance-transformer." Indeed, an excellent balun is optimized to take advantage of both phenomenon. ... Regards, JS This: http://www.pdftop.com/view/aHR0cDovL...8xQmFsdW4ucGRm is actually a pretty fair appraisal of it all ... beware line wrapping. Regards, JS |
Cecil, was it you that mention a "windom balun?"
On 9/13/2010 1:22 PM, John Smith wrote:
On 9/13/2010 1:17 PM, John Smith wrote: ... You might want to note that to Trask, he thinks it IS a current balun ... since it has the appearance of two 1:1 current baluns used on a single core, I tend to agree with his take on it. Regards, JS This core contains four windings, two on each side, they ARE wound to be two 1:1 current (guanella baluns.) The phase of one winding on the floating side is reversed, resulting in balun voltage being additive for that floating winding, alone. Regards, JS I should note, this is NOT misleading, the terminology clearly defines this balun as a "HYBRID" balun. Regards, JS |
Cecil, was it you that mention a "windom balun?"
Owen Duffy wrote in
: Roy Lewallen wrote in : The key to the answer is in two words in the first sentence of your posting: "immediately adjacent". You're certainly correct that the current can't abruptly drop to zero at the terminator, because of Kirchoff's Current Law. But the current doesn't abruptly end, rather it drops to zero following a sinusoidal distribution curve. It's quite My modelling experience is that other things like connection to ground, and open ends to conductors have more influence on the location of a standing wave pattern than typical common mode chokes. I have created a simple model of a Carolina Windom at 7MHz, assuming that the device at the dipole feedpoint is a 4:1 voltage balun with negligible common mode impedance, the isolater is 1000+j0 (your nomination), and a feedline configuration that demonstrates that the isolator has not caused a minimum in the common mode standing wave pattern at that point. A pic of the current distribution is at http://www.vk1od.net/lost/Clip043.png . ... Common mode chokes can be made pretty easily to have an impedance of more than 1k ohm. Both modeling and measurement show this is usually adequate in typical installations to drop common mode current to very near zero at the choke location. But you can easily have substantial current a quarter wavelength on either side of it. Didn't work for this case, the current minimum is about half wave between the isolator (left hand blue square) and the dipole, and the common current entering the shack (right hand blue square) is quite large. Apologies, there was an error in the model... I hadn't installed the source properly. I have replaced the pic at http://www.vk1od.net/lost/Clip043.png . The situation is a little different, but the isolator does not force a current minimim at its location, and the common mode current flowing at the shack is large. Owen |
Cecil, was it you that mention a "windom balun?"
Owen Duffy wrote in news:Xns9DF34D79C6188nonenowhere@
61.9.134.55: .... source properly. I have replaced the pic at http://www.vk1od.net/lost/Clip043.png . The situation is a little I have renamed it so that you get the new pic... http://www.vk1od.net/lost/Clip043.png |
Cecil, was it you that mention a "windom balun?"
On 9/13/2010 2:36 PM, Owen Duffy wrote:
My modelling experience is that other things like connection to ground, and open ends to conductors have more influence on the location of a standing wave pattern than typical common mode chokes. I have created a simple model of a Carolina Windom at 7MHz, assuming that the device at the dipole feedpoint is a 4:1 voltage balun with negligible common mode impedance, the isolater is 1000+j0 (your nomination), and a feedline configuration that demonstrates that the isolator has not caused a minimum in the common mode standing wave pattern at that point. A pic of the current distribution is at http://www.vk1od.net/lost/Clip043.png . ... Common mode chokes can be made pretty easily to have an impedance of more than 1k ohm. Both modeling and measurement show this is usually adequate in typical installations to drop common mode current to very near zero at the choke location. But you can easily have substantial current a quarter wavelength on either side of it. Didn't work for this case, the current minimum is about half wave between the isolator (left hand blue square) and the dipole, and the common current entering the shack (right hand blue square) is quite large. Apologies, there was an error in the model... I hadn't installed the source properly. I have replaced the pic at http://www.vk1od.net/lost/Clip043.png . The situation is a little different, but the isolator does not force a current minimim at its location, and the common mode current flowing at the shack is large. Owen A "4:1 voltage balun with negligible common mode impedance" isn't a common mode choke, and can't be expected to reduce the common mode current at its location. If that's what the Carolina Windom uses, I wouldn't be at all surprised to find in practice what you see in the model. In no way is a voltage balun a common mode choke or "isolator". When a load is asymmetrical with respect to ground, a voltage balun actually *forces* a common mode current to exist at its insertion point. Forcing equal voltages into unequal impedances results in unequal currents in the two conductors. The difference between the two is the common mode current. That's why I've tried for a very long time (at least since the publication of my balun article in 1985) to educate people that voltage baluns are not the things to use in antenna systems. My comments were strictly regarding the properties and uses of common mode chokes (current baluns), not voltage baluns. Roy Lewallen, W7EL |
Cecil, was it you that mention a "windom balun?"
On 13 sep, 16:07, Owen Duffy wrote:
lu6etj wrote : I agree with Cecil, Owen, I do not see nothing strange on have common mode current in one part of the line and not in the other, ideal choke it is an open circuit to RF currents. Miguel, There are two issues. Firstly, if the common mode choke (or isolator) is physically small with respect to wavelength, and there is common mode current on the line immediately adjacent on one side of it, why is there not an almost equal common mode current on the other side... or explain the current path that allows the first mentioned current AND that complies with Kirchoff's Current Law. Secondly, the common mode 'conductors' are coupled conductors. I see that Roy has dealt with that, so I will leave it at that. For these reasons, it is naive to think that a practical common mode choke has such extremely high impedance that the common mode current through the choke is zero, or even near to it. Even if it did drive common mode current to zero or near zero at that point, that does not mean there is no common mode standing wave, just that a node exists at that point. Ask yourself how whether the use of a common mode choke (isolator) to effectively reduce common mode current between the common mode choke and the tx don't also reduce common mode current between the common mode choke and the dipole feed point. Owen Owen It is obvious, we are talking about different things. External fields always will induce common mode currents in conductors, then it is virtually impossible completely remove it. We will have commond mode currents in our line if our ham neigbourhood turn on his TX or our wife talk near with her celluar phone too. When I talk about interrupt common mode current with choke I am not thinking in prevent all possibles external induction fields over the section of line isolated with the choke but in interrupt the current flow that would have in this point if not were the device placed. In that sense no puntual devices can avoid induction laws. Also, a good isolator it is a capacitor and always will allow displacement currents. From electromagnetic point of view the inductor field beyond the isolator or ideal choke it is the same that any other external field. Not work either if as isolating device I installed five meters of optical fiber and a pair of transducers :) Do you search for a TL incapable to induce external fields?, then we are not talking about baluns, perhaps we could talk about EM shieding of the TL. Similar situation if we install a perfect balun and run the TL paralel to the antenna, common mode current not depends. 73 Miguel LU6ETJ |
Cecil, was it you that mention a "windom balun?"
On 13 sep, 17:17, John Smith wrote:
On 9/13/2010 1:01 PM, Owen Duffy wrote: ... I might note here that a Trask 4:1 current balun is not a Guanella current 4:1 balun, they have quite different connections. The argument that Trask makes in support of his design on a single core does not apply to the Guanella design. Owen You might want to note that to Trask, he thinks it IS a current balun ... since it has the appearance of two 1:1 current baluns used on a single core, I tend to agree with his take on it. Regards, JS Owen It is obvious, We are talking about different things. Fields always will induce common mode currents in conductors, then it is virtually impossible totally remove it. We also will have commond mode currents in our line if our ham neigbourhood turn on his TX or our wife talk near with her celluar phone... When I (or "we") talk about interrupt common mode current with choke (or isolator) I am not thinking in prevent all possibles induction fields over the conductors. The goal is interrupt a current that would have in a point if the device (choke) it was not there (neither you hope for ideal behavior, we must be consecuent). In this sense no puntual devices can avoid induction laws. Also, a good isolator it is a capacitor and always will allow displacement currents. From electromagnetic point of view the inductor field beyond the isolator it is functionally similar to any other external field. Even if you install a five meter optical fiber with a pair of tranducers isolator betewen a line section you can not prevent electromagnetic coupling. Similar situation if we buy our ideal balun and then we run our line parallel to antenna :) Do you search for a TL incapable to induce external fields?, then we are not talking about baluns, perhaps we could talk about EM shieding of the TL. 73 Miguel LU6ETJ |
Cecil, was it you that mention a "windom balun?"
On 9/13/2010 3:07 PM, Owen Duffy wrote:
John wrote in news:i61i8h$png$4 @news.eternal-september.org: http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=16722 The source is actually http://www.saunalahti.fi/hohtola/ham...ndom-balun.htm , presented the the DXZONE front. Both baluns shown are current baluns, ie devices with a high common mode impedance. One of the advantages claimed of the Carolina Windom is the contribution of feedline radiation. If that was your objective, you would not employ devices (such as the current baluns in the referenced article) that reduce the commom mode feedline current. Of course, the objective is a specious one. If you wanted to minimise participation by the feedline as a radiator and pickup (especially noise, since it is often closer to some noise sources), then you might use an effective current balun. Indeed, more that one would probably be needed for an OCF dipole. Owen Yes, that is why I said I didn't run the windom in the first place, complete circle, completed perfectly ... Regards, JS |
Cecil, was it you that mention a "windom balun?"
On Sep 13, 12:47*pm, Roy Lewallen wrote:
The difficulty with having common mode current on one side of an "isolator" or common mode choke (current balun) is that it creates a field which couples to the line on the other side, generating a common mode current on the other side. Since I don't know how robust the Carolina Windom isolator is, my following statement may or may not apply to the Carolina Windom. The above problem goes away *if* the choking impedance is high enough to *cause* a common-mode standing-wave current node (minimum) at the choke because the net magnetic field is then near zero on both sides. The same thing happens when a well-designed trap is placed in a dipole. The high impedance of the trap at the parallel resonant frequency causes a standing-wave current node and reflects the forward wave back toward the feedpoint instead of allowing current to flow through it into the rest of the wire. Here's the current distribution on a trapped antenna. Note how the trap impedance causes a standing wave current node at the trap. http://www.w5dxp.com/trap.JPG -- 73, Cecil, w5dxp.com |
Cecil, was it you that mention a "windom balun?"
On Sep 13, 2:07*pm, Owen Duffy wrote:
For these reasons, it is naive to think that a practical common mode choke has such extremely high impedance that the common mode current through the choke is zero, or even near to it. Nobody said the Carolina Windom choke was that robust - just that it is possible to design a choke with a high enough impedance to cause a common-mode standing-wave node at the choke. Even if it did drive common mode current to zero or near zero at that point, that does not mean there is no common mode standing wave, just that a node exists at that point. There is a common-mode standing wave on one side of the choke and not on the other because the very high choking impedance reflects the common-mode traveling wave on one side of the choke back toward the source of the forward wave. I took a trapped dipole and dropped a wire from one end to mininec ground. The standing-wave current is free to flow through the choke and establish a standing-wave on the other side - but it doesn't. Here is what a robust isolator is supposed to do to the common-mode standing-wave current. http://www.w5dxp.com/trapgnd.JPG Again, I am not saying the Carolina Windom isolator is that good - just demonstrating a principle that you seem to be missing above. -- 73, Cecil, w5dxp.com |
Cecil, was it you that mention a "windom balun?"
On Sep 13, 5:19 pm, Owen Duffy wrote:
The NEC model I posted shows that a 1k isolator (common mode choke) is not effective for that purpose. Here's a model of a Carolina Windom on 20m with a 2k choke (isolator) 20 feet down the coax from the antenna feedpoint at a height of 50 feet. The maximum current on the coax braid above the isolator is 0.72 amps. The maximum current on the coax braid below the isolator is 0.14 amps. The radiation pattern is close to the advertised one for 20m. http://www.w5dxp.com/carwin20.JPG -- 73, Cecil, w5dxp.com |
Cecil, was it you that mention a "windom balun?"
On 9 sep, 16:26, lu6etj wrote:
On 6 sep, 13:14, Wimpie wrote: On 6 sep, 14:30, John Smith wrote: On 9/6/2010 5:08 AM, Cecil Moore wrote: ... The one I remember was about the Carolina Windom 4:1 voltage balun at the feedpoint and the 1:1 choke-isolator 20' down the coax. The original Windom was fed, Marconi style, against ground. -- 73, Cecil, w5dxp.com I have a "weird thing" about windoms ... I just don't trust an antenna which "manipulates" RF on the feedline in "beneficial" ways and has a religious cult following ... insane quirk of mine, really. lol *Now I don't have the room ... moved again. If the wife had her way, we would move to Montana next to a favorite sister and brother ... there we would have the room! lol Regards, JS Hello John, When the feed line goes to a clean environment (for example a ground provision far from the shack feed line radiation may not be a problem, but it isn't my favorite. *When the feed line goes directly to the shack (and equipment), I don't want such an antenna. When you are working NVIS on 75/80m, you don't want the vertical component as this leads to radiation under low elevation, hence stronger reception of ground based interference. In case of DX, the vertical component may help you as this may result in lower elevation of main lobe; over here we have much soil with better then average conductivity. If I would like vertical polarization, I prefer 100% of that, so no windom or OCF dipoles for me. Depending on the design, allowing vertically polarized radiation may result in worse or better VSWR. Regarding the color, many straight people wear it over here (especially in summer days), so you can't judge on color only.... Regarding the balun/transformer, you need a very good one with OCF dipoles as common mode voltage at feed point can be in the 300V range with 100W input. just some pF *stray capacitance in a transformer will provoke feed line radiation. Best regards, Wim PA3DJSwww.tetech.nl without abc in the address, PM will reach me.- Ocultar texto de la cita - - Mostrar texto de la cita - Hello boys, good day for you Is it Carolina Windom a balanced load to justify the name "balun"? We could think in a device to transform Z and another device to block feed line current. What do you think about it? Miguel Hello Miguel, I didn't follow this topic for some days. The two-step approach will work and you are right, "balun" is not a good word for an OCF dipole as a "balun" can also be a center-tapped transformer where the center is connected to the ground of the unbalanced side (voltage type balun). This one will not suppress common mode current in an OCF application. What you need is a "device" that does the required impedance transformation and accepts large common mode voltage at the high impedance side without introducing common mode current in the feed line. Regarding the two-step approach, I have a simple "device" for reception. It consists of a 1:3 (1:9 impedance ratio) ferrite auto- transformer (no galvanic insulation). The 50 Ohms side (coaxial) contains a three section common mode choke to avoid common mode current in the 50 Ohms feed line. Best regards, Wim PA3DJS www.tetech.nl remove abc from the address before hitting the send button. |
Cecil, was it you that mention a "windom balun?"
In message , John Smith
writes On 9/12/2010 9:45 AM, lu6etj wrote: ... Although this is a more important issue, I insist in my original point, is it "licit" to call "balun" a device connected to two unbalanced circuits (line and antenna)?, Is it Carolina windom a balanced antenna? Here most of hams tend to call balun any toroidal transformer, with TL or traditional windings connected to any circuit! :) What you say? Thank for your interest and answers. Best regards to you and all friends. Miguel LU6ETJ Actually, balun = "balanced-to-unbalanced", and unun = "unbalanced-to-unbalanced." I believe that is correct. And, I am in agreement, I see isolation RF transformers, RF auto-transformers and transmission-line-transformers and UNUNs' all grouped together under "balun." It would be nice to have standardized terminology and everyone is encouraged to use it ... Other than that, the rest of your post is sure to fire debate, assuming that everyone even recognizes the above ... I think that the simple explanation why 'ununs' get misnamed as baluns' is that, in their wound transformer form, they often look very similar. It doesn't help that, depending on how it is wound and connected, one transformer can sometimes be connected to serve either as a balun or an unun - and, in many cases, also an impedance transformer. As far as I'm concerned, while I've known the term 'balun' essentially 'for ever', I had never come across the newly-coined 'unun' until fairly recently. It was probably simply known by its function, ie an 'RF transformer'. I have to confess that I don't know why 'unun' has become popular. It's a rather 'ugly' word, and is somewhat difficult to say clearly. Maybe that's why they get mis-called 'baluns'! There is absolutely no reason why there should be any real confusion between a 'balun' and an 'unun' (other than carelessness, or ignorance of their function). If you want to group them together, they should probably come under a general heading of "RF Transformers, and RF Matching and Other RF Interface Devices" (or maybe something even more long-winded). -- Ian |
Cecil, was it you that mention a "windom balun?"
On 14 sep, 01:10, Cecil Moore wrote:
On Sep 13, 5:19 pm, Owen Duffy wrote: The NEC model I posted shows that a 1k isolator (common mode choke) is not effective for that purpose. Here's a model of a Carolina Windom on 20m with a 2k choke (isolator) 20 feet down the coax from the antenna feedpoint at a height of 50 feet. The maximum current on the coax braid above the isolator is 0.72 amps. The maximum current on the coax braid below the isolator is 0.14 amps. The radiation pattern is close to the advertised one for 20m. http://www.w5dxp.com/carwin20.JPG -- 73, Cecil, w5dxp.com Hello boys (greteengs Wimpi, how are you? For monoband applications we can get more Z from a coaxial choke making the winding for autorresonance. K1TTT have a good data table. Time ago I want test differents antenna to lift with a kite and I found = http://www.io.com/~n5fc/rfd.htm, the idea seems to me interesting enough to make some test that are descibed here = http://www.solred.com.ar/lu6etj/tecn...evisada-en.htm from here I think of another use of de "coaxial trap" to get more Z from coaxial winding specially in monoband antennas, I named de critter "The Trap balun" = http://www.solred.com.ar/lu6etj/tecn...a_balun-en.htm 4NEC2 simulations and real field test show me both approachs works fine :) Miguel Ghezzi LU6ETJ |
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