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Old October 5th 03, 01:12 PM
Ralph Mowery
 
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And no, a dipole doesn't have a feedpoint impedance of 70 ohms. In free
space, if it's very, very thin, resonant, and perfectly straight, it
will have an impedance close to that. But you can't construct one in
free space. Over ground, expect anything from about 50 to 100 ohms
depending on height and diameter. And that's only at the single
frequency at which it's resonant. QSY a few kHz, and there goes all your


YOu are correct on the impedance of a real dipole. My 80 meter dipole is up
about 30 feet on each end but sags to about 20 feet in the middle. It is
almost 1:1 at the frequency I cut it for . That makes it closer to 50 ohms
than it is to 70 ohms.