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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 ![]() ![]() Greetings Miguel |
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