> I thought I would add some specific pertinent data in response to your
> question (words are always cheap) A beam with 13 directors, 3 being
> reflectors on approx 1 WL boom gives a PEAK F/B of over 60 db along
> with a F/R of around 50. Don,t ever recall running into those sort of
> figures on other designs with a single reflector (maybe someone will
> enlighten me)
> Regards
> Art Unwin KB9MZ
My three element 40 meter antenna has a F/R of over 50 dB.
It has one reflector, one driven element, and one director.
It is limited in null depth, in direct actual measurements, by the
ability to physically hold the elements steady and by scattering
from the surroundings rather than the any lack of additional
elements.
It is actually quite easy to get values that high in 3 element
antennas, since they can be made to have nearly perfect current
ratios in the elements (1,2,1 ratio).
73, Tom W8JI
w8ji@contesting.com
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