TopBand: FORCE-12 ANTENNAS

[Frank R. Smith]

DX Friends:

At the risk of upstaging any of Force-12's own material about
a new Force-12 antenna, their new WARC-7, I wanted to make a few
of my own comments in behalf of the K7K Kure DXpedition team.

We were very lucky to have received Force-12's new WARC tribander
just in time for our DXpedition departure.  Constructed using
linear loading on three elements,  the beam consists of 7 elements, 
2 on 30, 2 on 17 and 3 on 24.

As with other Force-12 beams, the antenna is quick and easy to
put together.  In fact, we had lost the instructions, and due
to our familiarity with constructing other Force-12's and thanks
to clear marking on factory-installed element mounting brackets,
Andy UA3AB and I were able to put the antenna together without
instructions.  The whole process took us less than one hour and
we had the beam up on a mast and on the air.

In assembling the elements themselves, it is a total impossiblity
to couple the aluminum tubes incorrectly.  Each juncture requires
rivets into factory pre-drilled openings with a unique pattern of
rivet openings at each juncture.  If you get the tubes backwards,
the rivets won't match.  And unlike other antennas, there's
absolutely no need for a measuring tape and the frustration of 
using stubborn hose clamps.

Putting the WARC-7 on the air, of course, is the most important
test.  The antenna was especially effective on 10.1 and 18 mHz especially
since that's where the propagation was favorable (for us), but upon
QSYing to 24 mHz we had very good signal reports.  But "good"
is a weak word here.  Reports were consistent that the signals on
these bands were among the strongest.  We would become accustomed to
hearing very nice adjectives like "fabulous signal", "one of the best
on 18 I've ever heard," "a true twenty over", etc.

And all this with relatively low power!

The only problem we encountered with the antenna was a male Frigate
bird who took a liking to the reflector and decided to make the 
WARC-7 his new perch on Kure.  No amount of shaking and rotating
would dislodge the stubborn bird.  The second nighttime of the 
operation, the Frigate bird landed onto the antena with such force
that the antenna shifted inside the mounting bracket leaving the 
antenna somewhere between horizontally and vertically polarized!
But it still worked great.

If anyone reading this is considering a new WARC antena, we'd 
recommend serious consideration of tihs new Force-12 WARC-7 beam.
We've got several orders of our own in already so you'll have to
get in line!

73

Frank Smith AH0W/OH2LVG
Midway-Kure DX Foundation


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