Thanks for the reply, Steve, but I'm sorry ... that doesn't make sense.
Torque is torque, and it's in the same direction no matter which side of
the mast is applying the torque.
Picture this ... I have a turnstile on the ground with one long pole
clamped to it. I get Person A to push one end of the pole clockwise
(when viewed from above) and Person B to push clockwise on the other end
of the pole. Now I add a second pole to the turnstile, but I clamp it
to the turnstile on the opposite side of the turnstile from the first
pole. I add Person C and Person D to push the second pole ... also in a
clockwise direction. All four people are pushing clockwise and their
torque vectors add.
Again, it is important to understand that I get strong SWIRLING wind
gusts ... literally mini-tornadoes. If one of them (I'm going to assume
it is swirling counterclockwise when viewed from above) hits my tower
head on from the south, and my boom happens to be oriented east-west,
half of the swirling wind tries to push the eastern half of the boom
north while the other half of the swirling wind is trying to push the
western end of the boom south. Those are additive torques no matter
which side of the mast the boom is attached to. And if you think about
it, the same problem exists no matter which direction I have the
antennas pointed.
73,
Dave AB7E
On 12/10/2017 11:36 AM, k7lxc@aol.com wrote:
> The problem is that in the springtime when it gets really windy here,
the high ridge line to the west and south of me blocks those
prevailing
winds and turns them into swirling wind gusts that AVERAGE
anywhere from
50 mph to 80 mph about every three to five minutes ... with peaks
sometimes reaching 90 mph on a bad day. When those swirlers hit the
tower head on, the forces on each end of the boom don't balance
... they
add. The resultant torque on the mast must be tremendous, and in any
case it eventually managed to strip the gears in the NE position.
If the antennas are mounted on the same side of the mast -
yes, the additive torque is significant. My advice is to mount the
antennas on opposite sides of the mast. That way, much of the
torque is cancelled out. Dick Weber pointed this out in a QEX
article years ago. That should have positive effects on your
rotator as well.
Cheers,
Steve K7LXC
TOWER TECH
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