I have the Force 12 40 mtr beam on a 120 ft tower and I am very satisfied
with its performance. Mine is actually a 620/340 on a 47 ft boom. This
antenna is not on the web sight or catalog. Mine uses the "N" elements
as compared to the MAG 620/340 which is on a 44 ft boom and uses the linear
loaded 44 ft elements. I originally had the Mag model and the 40 mtr beam
was average (the 20 was a flame thrower). Converted over to the longer (and
beefier) boom and the N 40 mtr elements about a year ago.
Two of my friends also have the Force 12 40 mtr beams with the N elements
and they are also very pleased. If you tune them for around 7.1Mhz or so,
it will cover the whole band.
Since you are installing the antenna at 150 ft, I would suspect that a "wet
noodle" would play pretty well. Anyway, you mentioned stacking and if you
are thinking of something for 20 mtrs, the antenna I have would save you the
need for an additional ring rotor.
Dick Williams K8ZTT
PS. Not wanting to "waste aluminum", the old 44 ft boom and 80 ft tower
it was on became a Force 12 717 at 80 ft. The 7 elements on 17 mtrs is a