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Old August 15th 07, 04:45 PM posted to rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Mike Kaliski Mike Kaliski is offline
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First recorded activity by RadioBanter: May 2007
Posts: 182
Default VSWR Meter and reactance


"amdx" wrote in message
...
Is it possible for a VSWR meter to read 1 to 1 with reactance at the
antenna?
Ex. If the antenna Z was R= 30 and X= 40 would the meter read 1 to 1?
Or is there a combination of R and X that would give 1 to 1?
Thanks for your answer and
explanations,
Mike

Mike

The VSWR meter is showing power reflected back down the line to the meter.
If the line is very lossy, like a long length of coax that has been
penetrated by water, the reading may well show 1:1 but the radiated power
will be zero. On its own, the VSWR meter provides a very useful indication
that the antenna system is matched to the output of the transmitter. It is
not a guarantee that the system is actually radiating a signal. A simple
field strength meter will give an indication that the power supplied via the
feeder to the antenna is actually being radiated rather than absorbed.

Cheap VSWR meters can be quite inaccurate when presented with loads which
differ from their design impedence. Used with an understanding of their
limitations, they are fine for everyday ham use, but something a bit more
sophisticated is needed for serious antenna system measurements.

Mike G0ULI