At 3:56 PM -1000 12/12/02, Jim Reid wrote:
>...Proper way to do a real, out in the feild test of an antenna's
>radiation pattern, would be to have the rcv'ing gear up in a
>helicopter flying at just the correct altitude to be at the correct
>height for the distance/radiation angle calculation for the
>particular antenna under
>test, wouldn't it?
Yes. That's done. Airplanes and balloons are also used.
HF wavelengths are so large that it can be difficult getting out of
the near field, and difficult getting the earth out of the way. So
small scale model antennas (and model airplanes or ships or whatever
the HF antennas are intended to be mounted on) are often built and
measured at scaled wavelengths, in other words at UHF or microwave
frequencies.
-Chuck, W1HIS
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