Al,
I believe you'll find that F12's stated gains are based on a height of 74' on
40M and 140' on 80M. Try these heights in EZNEC and see if the results are
closer. Just doing a real quick look using HFTA, I see as much as 5dbi
difference between 2ele at 72' and 140'.
73, Bob W7BJ
The Force12 uses both relay switched coils (for moving resonant frequency in
the band) and linear loading for the 80m on both elements. Using Eznec I have
not been able to get gain when the linear loaded is placed at the center of the
elements but I can get about 3.5 db gain when the loading is moved to the end
of the elements similar to the Steppir 40m dipole addition. (I didn't model the
coils). Force12 specifies about 4 db gain with their center loading
installation. It may be that my model is inaccurate. The height that I have
modeled is 72' which is the height that I would install it on a LM470 crankup.
So far I have only heard from on other "user" of the Mag2/2. He bought it
used and decided not to install it! I will appreciate comments.
k7puc
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