>It's either the Force12 5 element or the M2 4 element 20M4DX.
Both have 1/2 wave booms - 36ft.
Tony, the best way to answer your question is
to see full curves for Gain, F/R and SWR for both
antennas...i.e. modeling. However, if you don't have
those, here's my guess based on looking at a lot of
optimized 5 element designs on 10 meters.
1. 1/2 wavelength is very short for a 5 element.
2. 3/4 wavelength is about optimum for a 5 element.
3. The above assumes traditional designs, not a
dual-driven cell (like KLM) or the OWA trick of a
very close spaced first director. If that is done,
then the 5th element might buy some SWR bandwidth,
but probably not much in Gain or F/R. I'm not
familiar with the Force12 and can't find a picture
of it on their website, but my guess is they are
using an OWA design or variant.
4. I would probably go with the 4 element for
reasons of cost, wind loading and weight without
any more info than you have given.
Have you asked both manufacturers for full
Gain, F/R and SWR bandwidth curves? Surely they
have them since both Force12 and M2 use modeling.
They might forward them to help in your decision.
73, Bill W4ZV
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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