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#11
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If you have a 1.5 swr your antenna isn't resonant Sorry, but thanks for playing. Your resonant impedance may be pretty much anything, depending on the exact antenna in question. We favour antennas that are roughly 50 ohms resistive at resonance. Resonance is the point(s) where the antenna has little to no reactive impedance component. My cobra for 11M is about 2/1 and is definitely resonant. |
#12
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#13
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In , Radioman wrote:
If you have a 1.5 swr your antenna isn't resonant Tnom, Frank, smack his pee pee until he understands that 1:1 and resonance are related but different. You can have one without the other. Tell you what, put a 102 inch stainless steel whip on the roof of your clunker. Use a 4 inch heavy duty spring. Use enough coax to reach the radio. Measure SWR. Tell us what you get. Respond before December 31st. Let's clear up a few CB myths here....... First, the ONLY thing an SWR meter can tell you is how much power -inside- the coax is going in the wrong direction. It -can't- tell you why. SWR does not distinguish between an antenna and a dummy load, nor does it care about errors due to improper or untuned grounds, RF on the coax, the length of the coax, the type of antenna, etc, etc, etc. In fact, an SWR meter can show a 1:1 ratio with no load at all depending on your coax length and whether the end is open or shorted -- it's called a tuned stub!!! Second, it is the -efficiency- of the antenna that is important. This should be a rule: If you want resonance, use a grid-dip oscillator; if you want maximum field strength, use a field strength meter. (duh!) If anyone wants proof of this, plot the SWR and the relative field strength across the band -- you will find that they peak at different frequencies. Finally, the SWR meter is good as an indicator of fault or failure in a working antenna system, and then only if you know what the SWR should be when the system is working properly. That's the way it should be used. It should -not- be used to tune an antenna. A field strength meter is less expensive, easier to use, and directly measures the strength of the transmitted signal (which is what you really want to measure anyway!). -----= 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! =----- |
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