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## Re: [TowerTalk] Recommendation for mast on bottom mount rotator

 To: "'K8RI on TowerTalk'" , Re: [TowerTalk] Recommendation for mast on bottom mount rotator "Gary Schafer" Tue, 19 Sep 2006 23:25:38 -0500
 ```Thanks Roger, I agree with what you are saying. The torque equalization could happen only if the wind was at the perfect angle. If a single antenna, or one on each side of the mast, were getting hit with wind that caused them to turn then the probability of them turning in the same direction is high. With the wind at the "ideal angle" so that the torque with the two antennas would balance, would give little rotational torque with a single antenna (or two on the same side) to start with. The antenna being offset on the mast by a couple of inches from dead center is going to make little difference in torque balance. In order to be effective the wind would have to be blowing directly at both antennas at an angle that would cause little rotational torque on either antenna, in which case there would be little rotational tendency to start with. Otherwise both antennas would produce torque in the same direction. 73 Gary K4FMX > -----Original Message----- > From: towertalk-bounces@contesting.com [mailto:towertalk- > bounces@contesting.com] On Behalf Of K8RI on TowerTalk > Sent: Tuesday, September 19, 2006 10:47 PM > To: towertalk@contesting.com > Subject: Re: [TowerTalk] Recommendation for mast on bottom mount rotator > > > 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 > >> > >> > >> > >> _______________________________________________ > >> > >> > >> > >> _______________________________________________ > >> TowerTalk mailing list > >> TowerTalk@contesting.com > >> http://lists.contesting.com/mailman/listinfo/towertalk > >> > >> _______________________________________________ > >> > >> > >> > >> _______________________________________________ > >> TowerTalk mailing list > >> TowerTalk@contesting.com > >> http://lists.contesting.com/mailman/listinfo/towertalk > > > > > > _______________________________________________ > > > > > > > > _______________________________________________ > > TowerTalk mailing list > > TowerTalk@contesting.com > > http://lists.contesting.com/mailman/listinfo/towertalk > > > > _______________________________________________ > > > > _______________________________________________ > TowerTalk mailing list > TowerTalk@contesting.com > http://lists.contesting.com/mailman/listinfo/towertalk _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread Re: [TowerTalk] [SPAM] Re: Recommendation for mast on bottommountrotator, (continued) Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K8RI on TowerTalk Re: [TowerTalk] Recommendation for mast on bottom mount rotator, ersmar Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K8RI on TowerTalk Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K7LXC Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K8RI on TowerTalk Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K8RI on TowerTalk Re: [TowerTalk] Recommendation for mast on bottom mount rotator, Gary Schafer <= Re: [TowerTalk] Recommendation for mast on bottom mount rotator, K7LXC