>From: Henry Knoll <Henry.Knoll-1@tc.umn.edu>
To: <topband@contesting.com>
>Date: Sat, 2 Nov 1996 21:40:13
>
>In reading some of the threads which mention radiation resistance
>of an antenna, I gather the following:
>
>Radiation resistance is not the same as feed point resistance.
>
True. Feedpoint resistance includes loss resistance plus radiation
resistance.
>Average Joe Ham has no way to measure radiation resistance of an
>antenna, and even professionals can only measure antennas of
>small size. Is this correct?
Essentially (not sure about the size limitation).
>If not, how can I measure the radiation resistance of my TH-7?
>
You probably can't. But you really don't need to. The real question is
why would you want to? Since you can't really do anything significant
about either the radiation resistance or the loss resistance (unless you
want to make it more lossy) of that antenna, to what use could you put the
information if you had it? If it is just a matter of satisfying curiosity
(a noble goal in itself), any of the various NEC-2 based modeling programs
will get you very close to the actual values if you feed the program an
accurate description of the antenna and traps.
>What is the proceedure for measuring the radiation resistance of an
>antenna, step by step for us dummies?
>
I don't have a good one.
>It seems that if I know the radiation resistance of the antenna, I
>can calculate the efficiency--Yes?
>
>73 Henry WA0GOZ
>
Yes.
73, Eric N7CL
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