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Old March 6th 07, 02:30 AM posted to rec.radio.amateur.antenna
Wayne Wayne is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 409
Default Measuring Antenna Efficiency


"Roy Lewallen" wrote in message
...
Wayne wrote:

Thanks for the reply. My dipole example is intended to avoid
transmission line issues by not having one, and the elements are assumed
to be reasonably low loss. If I do some quick back-of-the-envelope
calculations, for a VSWR of 1.3:1, I get an efficiency of about 98.3%
(using the equation 1-gamma^2). Assuming a resistance of 1 ohm in the
dipole conductors the efficiency I calculate is about 98.6% (72/73).

Are there any other loss issues missing in this example.


There is no relationship between SWR and efficiency.

Roy Lewallen, W7EL


Agreed. For example, SWR into a dummy load. The equation given was just to
show the approximation I was trying to make for the dipole case.