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#1
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BuckEye wrote:
Why does the coil make it that way. Nowhere in any theory does it state that. Its just another ways to match the coax to free air. That's all the antenna does. Why do you keep trying to say its "electrically" a 1/4 wavelength. Just because it can be loaded with a matching device ? Shows a good match. This could be taken to the extreme and if the antenna was reduced to only one inch in length, tuned and matched would it be electrically" a 1/4 wavelength . No its just a resonate circuit with no relation to a wavelength. In fact a conductor does not have to be any wavelength to radiate at all. Any antenna, even a straight piece of wire has inductance at radio freqencies. A 1/4 wave straight piece of wire will exhibit a certain inductance at a certain frequency, shorten it to something less than a 1/4 wave and the inductance decreases. Add a coil to make up the missing inductance and the antenna "looks" like a 1/4 wave again to the RF source. Some of the power is dissipated as heat in the coil because of the I/R losses of the coil. |
#2
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What makes a antenna so called " looks like a 1/4 wave again to the RF".
Where does it say a matching antenna must look like a 1/4 anyway. "Add a coil to make up the missing inductance and the antenna "looks" like a 1/4 wave again to the RF, not so, the impedance is now very low at its feed point. Big mismatch (you forgot the extra device now needed to match the antenna,usally a cap or coil on the input side.so adding just a loading coil did not make it look like a match.Notice I said a match . NOT a 1/4 wave. RF doesn't care what the wavelength is. Where does it say a antenna must "look like a 1/4 anyway." The same thing could be said about a base matched 5/8 wave antenna, it shows a good match also and its is a long way from the 1/4 wave length. and is never said it looks like a 1/4 to the RF. Don't confuse a match to it looking like a 1/4. There is many things that can be changed at the antenna mounting spot, 1/2 wave 5/8 wave |
#3
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![]() BuckEye, But all antennas are 'matched', be they exactly a 1/4 wave length long, or 75 feet long, or 1 inch long. I'm assuming that you mean impedance matching, right? Impedance matching has nothing to do with an antenna being resonant. 'Doc |
#4
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What the hell do you think I am saying.
This all started when some dumass said a antenna was electrically 1/4 wave long, not 1/4 wave antenna. You either have a 1/4 wave antenna or you don't. If its shorter, then its not a 1/4 wave antenna. In most cases it loaded, and no more electrically a 1/4 wave long antenna. How hard is this to understand. I think this comes from some adds that's states it a helical loaded 1/4 wave antenna that is only 56" long which is bull . Just like some other adds that claim their antenna is a 5/8 antenna wound on a fiberglass rod only 5' tall now go figure, I guess some also believe this . "'Doc" wrote in message ... BuckEye, But all antennas are 'matched', be they exactly a 1/4 wave length long, or 75 feet long, or 1 inch long. I'm assuming that you mean impedance matching, right? Impedance matching has nothing to do with an antenna being resonant. 'Doc |
#5
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Hrm.. ever stop to think that maybe the wire helically wound around
the shaft might be 1/4 wave long? That would make it a 1/4 wave helically loaded antenna. Just because the physical length of the antenna is less than 1/4 wave at the desired frequency doesn't mean the antenna isn't. Don't believe me? Try looking up "folded dipole" on the 'net.. -SSB BuckEye wrote: What the hell do you think I am saying. This all started when some dumass said a antenna was electrically 1/4 wave long, not 1/4 wave antenna. You either have a 1/4 wave antenna or you don't. If its shorter, then its not a 1/4 wave antenna. In most cases it loaded, and no more electrically a 1/4 wave long antenna. How hard is this to understand. I think this comes from some adds that's states it a helical loaded 1/4 wave antenna that is only 56" long which is bull . Just like some other adds that claim their antenna is a 5/8 antenna wound on a fiberglass rod only 5' tall now go figure, I guess some also believe this . "'Doc" wrote in message ... BuckEye, But all antennas are 'matched', be they exactly a 1/4 wave length long, or 75 feet long, or 1 inch long. I'm assuming that you mean impedance matching, right? Impedance matching has nothing to do with an antenna being resonant. 'Doc |
#6
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In rYlob.66399$Tr4.188400@attbi_s03, "BuckEye" wrote:
What the hell do you think I am saying. This all started when some dumass said a antenna was electrically 1/4 wave long, not 1/4 wave antenna. You either have a 1/4 wave antenna or you don't. If its shorter, then its not a 1/4 wave antenna. In most cases it loaded, and no more electrically a 1/4 wave long antenna. How hard is this to understand. I think this comes from some adds that's states it a helical loaded 1/4 wave antenna that is only 56" long which is bull . Just like some other adds that claim their antenna is a 5/8 antenna wound on a fiberglass rod only 5' tall now go figure, I guess some also believe this . Gee, so you finally read a book and discovered that you were wrong. Fine. But playing semantics in order to save face is a Twistedhedism. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#7
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![]() BuckEye, Hi. 'Dumass' here. Like it or not, antennas can and are classified and/or described by their 'electrical' length. Electrical length and physical length don't have to be the same and seldom are when speaking about 'loaded' antennas. When you find your self in a situation where everyone else seems to be wrong, and only you are right, it sometimes helps to stop and re-evaluate your position. Is it mandatory that you think about antennas the same way I do? Nope, sure isn't, but it does help if you at least understand 'where' the other person is coming from, or talking about. It always helps to view things from a different perspective. When you don't, the loss is yours... 'Doc |
#8
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On Fri, 31 Oct 2003 05:35:36 -0600, 'Doc wrote:
BuckEye, Hi. 'Dumass' here. Like it or not, antennas can and are classified and/or described by their 'electrical' length. Electrical length and physical length don't have to be the same and seldom are when speaking about 'loaded' antennas. When you find your self in a situation where everyone else seems to be wrong, and only you are right, it sometimes helps to stop and re-evaluate your position. Is it mandatory that you think about antennas the same way I do? Nope, sure isn't, but it does help if you at least understand 'where' the other person is coming from, or talking about. It always helps to view things from a different perspective. When you don't, the loss is yours... 'Doc Doc; I think he was calling me the dumbass, not you. At first I just thought he didn't understand the theory that was being posted here and wanted to learn. Hopefully he won't have the same problems reading a book. Like you said his loss. |
#9
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In , 'Doc wrote:
snip When you find your self in a situation where everyone else seems to be wrong, and only you are right, it sometimes helps to stop and re-evaluate your position. Wise words for anyone in a similar predicament, and especially for certain paranoid individuals who incorrectly perceive the situation as some sort of newsgroup conspiracy. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#10
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Quoted:
When you find your self in a situation where everyone else seems to be wrong, and only you are right, it sometimes helps to stop and re-evaluate your position. That's strange. Even Einstein found himself in that position. |
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