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Old November 12th 03, 10:09 PM
Frank Gilliland
 
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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!).








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