Theoretically it means that if both are subjected to the same velocity wind,
one will attempt to turn the mast CW while the other will attempt to turn it
CCW with the same force if they are both pointed directly into the wind.
However in the real world The wind rarely blows at the same velocity even
with an elevation difference of only 10 feet. Add to that gusting, element
elasticity, and mast elasticity and the results are far from being as
predictable as the math says they would be in a steady state. Even though
they are mounted on opposite sides of the mast they are just as likely to
end up at times trying to turn in the same direction.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)
> Ok, thanks Mike. I now know what alternately means but I don't see how
> that
> will alleviate any torque issues on the mast. What am I missing?
>
> 73
> Gary K4FMX
>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com [mailto:towertalk-
>> bounces@contesting.com] On Behalf Of Mike Fatchett
>> Sent: Tuesday, September 19, 2006 9:54 PM
>> To: 'Gary Schafer'; K7LXC@aol.com; towertalk@contesting.com; K8RI-on-
>> TowerTalk@tm.net
>> Subject: Re: [TowerTalk] Recommendation for mast on bottom mount rotator
>>
>> Mounting one antenna on one side of the mast and the next on the opposite
>> side etc so the boom to mast clamps alternate.
>>
>> Mike W0MU
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of Gary Schafer
>> Sent: Tuesday, September 19, 2006 8:50 PM
>> To: K7LXC@aol.com; towertalk@contesting.com; K8RI-on-TowerTalk@tm.net
>> Subject: Re: [TowerTalk] Recommendation for mast on bottom mount rotator
>>
>>
>>
>> > > Remember this mast has to do basically what the top mast does. It
>> > > is
>> > one
>> > long torsion bar.
>> > That and with a thrust bearing at the top the tower will end up
>> > supporting all the extra weight of the masting.
>> >
>> >
>> > Umm, I'll go with the long torsion bar. BTW, mounting
>> > antennas alternately up a mast goes a long ways to minimizing torque
>> > since they'll cancel each other out. (Article in QEX or QST by Dick
>> > Weber, K5IU, PE.)
>> >
>> > Cheers,
>> > Steve K7LXC
>> > TOWER TECH
>>
>> What do you mean by "mounting antennas alternately up a mast"? Pointing
>> them
>> at 90 degrees to each other?
>>
>> 73
>> Gary K4FMX
>>
>>
>>
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>
>
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