I am using the Cushcraft D3W rotatable diapole mounted 7 feet above my low
band beam and it works great on 12 and 17. The recommendation is that you
keep it at least 5 ft and preferably 10 ft above a low band beam. The SWR is
just fine.
Only adds .9 sq ft windload too!
If you are like some and get a 12/17 mtr rotatable diapole and dont have
enough
room to mount it at least 5 ft above the beam a great trick is mount it at a
right angle
to the boom of the beam and you can lower it to as close as a foot and the
antennas wont see each other (to any great extent). I did this for a while
and then increased the length of the mast and extended the space between the
beam and the diapole.
But it worked well at the right angle with the shorter mast.
If you have enough wind load capacity (I didnt) check out the Cushcraft and
Hygain beams for the 12/17 mtr bands. They really do one nice job.
I used a sloper for 17 but believe me the rotatable diapole is definitely an
improvement.
Good luck!
73
Mike
K0BUD
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