Ken,
I would rather deal with the antenna having the higher 'R'. The reactance
can be easily tuned out with a capacitor or an inductor, but the return path
losses (usually ground loss) on the antenna with the low resistance become a
higher percentage of the total, and the antenna having the higher R will be
more efficient - the SWR alone does not tell the whole story.
To illustrate - assume a 12 ohm return path loss resistance and the
reactance component properly compensated - with the 6 ohm antenna, the total
resistance is 18 ohms and 1/3 of the signal is radiated, but with the 48 ohm
antenna and the same 12 ohm return loss, the total resistance is 60 ohms and
4/5 of the total signal is radiated. The actual return resistance may vary,
I just used 12 ohms because it made the resulting numbers come out easily -
the principle is still the same with any other value.
73,
Don W3FPR
----- Original Message -----
While setting up a dipole antenna tonight a question come up while
discussing the tuning with myself: Which is the "most effective" antenna -
understanding it will be matched with a antenna tuner, either the internal
autotuner or an external manual tuner - a dipole type antenna with a
resistance of R=6 ohms and impedance of X=16, or the same dipole type
antenna with R=48 and X=146? Both of these settings have the same SWR=6.5
I guess that same question would apply to a short vertical, or end fed zepp
type antenna.
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