Windom antennas - down to earth
On Sun, 18 Mar 2007 14:31:38 -0400, Fred McKenzie
wrote:
Using the modeling software, is there a feed-point where impedance is
close to an available balanced feed-line on multiple bands? As close, I
would accept a 2:1 SWR.
Hi Fred,
The usual designs include a BalUn that transforms from a higher drive
Z to the 50 Ohms of a line. In that sense, the Off Center Dipole
introduces accessible resonances at every harmonic instead of at odd
harmonics. Depending upon the offset, some come into play, some go
out and for a variety of transformations. Some suggest 2:1, others
4:1, and yet others higher.
And you would still need to decouple the line (if the BalUn design
doesn't already answer that). Given the field imbalance, it may
require an aggressive decoupling (a second choke, or a distributed
choking). I have a large document available to those whose mail box
can stand the load.
73's
Richard Clark, KB7QHC
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