Having owned Telrex from the 70s, F12 and M2 from the 90s, M2 and built my
own currently, elements are not what they always seem. The 6 - 8 el 20M
yagi discussion shows that clearly.
An 8 el yagi on a 110 ft boom (K5GO) is likely using all elements in
traditional gain fashion.
A 7 el OWA yagi on a 70 ft boom is really a traditional 6 el Wide spaced
yagi with the OWA design of broad banding the DE with a close spaced
additional element.
My 15M 8el - 45 ft boom Telrex has 2 elements that are modifying the SWR
bandwidth interlaced in the Directors.
My 15M 6 el M2 45 ft boom yagi has neither the OWA element nor the old
Telrex method.
The gain of the 2 15M yagis are virtually identical and are phased at N1UR.
Note that the location of the DE on the boom is not exactly the same but I
just accept that small phase difference.
Gain is pretty much about boom length to a large extent with element
strategy tweaking up and down off that macro number. You can usually
compare an OWA yagi and a traditional yagi by subtracting one element from
the count of the OWA assuming the boom length is pretty much the same.
Sometimes there seems to be implied confusion about the above the way people
describe yagis.
73
Ed N1UR
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