[TowerTalk] CushCraft Query
jimlux at earthlink.net
Thu Jun 22 14:04:06 EDT 2006
At 10:16 AM 6/22/2006, Kent Tiburski wrote:
>Changing the DE might give a different feed impedance, but as far as the
>it changing the pattern , etc., it will still be the same.
I haven't actually tried it, and a well designed experiment beats pages of
theory, but theory says that changing the impedance of any element changes
the relative currents in the elements which changes the pattern.
The easy exception would be if the impedance change is due to some sort of
broadband untuned matching device between feedline and feedpoint, like a
But if the matching device is reactive this would change the impedance that
the element is "looking into" and that would change the currents among the
elements too. Reactive matching networks are pretty common on single band
antennas, for example a LC network, whether lumped or distributed(like a
gamma match). On a multiband antenna, who knows?
More information about the TowerTalk