Thread: Multi wavelength antenna
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Old September 2nd 08, 11:54 AM posted to rec.radio.amateur.antenna
Highland Ham Highland Ham is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 250
Default Multi wavelength antenna
wrote:
I have a lot of space available for antenna installation and i am
wondering if installing a 4 or 8 wavelength antenna would provide
increased performance or problems. For instance, instead of a 120 ft
dipole for 3900 khz a 480 ft or 960 ft.

I would be installing across a valley so ends would be about 25-30 ft
off the ground and the center would be about 80-90 ft off the ground.
=======================================
With so much space and assuming you talk dipole ,if you make each half
of the dipole an odd number of quarter wave lengths ,the impedance at
the feeder connecting point would be low.
Then you can either have a coax feeder (with 1:1 balun at dipole centre)
or a twin feeder preferably but not necessarily having a (electrical)
length of half a wave length or a multiple thereof resulting in a low
impedance at the matching box (tuner if you like) .

Frank GM0CSZ / KN6WH


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