A vertical dipole with the feedline coming straight off of the side for at
least 1/4 wavelength should have a near prefect circle/round pattern. This
of course can be impacted by variations in ground resistance in the near
field. Should the feedline not exit for 1/4 wave there will be some
interaction with the radiation patter.
I'm curious about this. Of course in order that the radiated RF from the
vertical dipole does not induce undesired currents in the feedline, the
feedling should run perpendicular to the dipole for as far as is
practical. Is 1/4 wavelength really far enough? At what distance is
does the current induced in the feedline, if it were parallel to the
intentionally radiating element, become insignificant?
In parasitic arrays aren't director elements sometimes more than 1/4
wavelength from another element? If being that far away made interaction
insignificant, there would be no benefit in adding that element.
DE N6KB
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