[TowerTalk] tower/rotator woes...

[Jim Thomson]

Date: Mon, 20 Feb 2017 17:05:23 +0000
From: Ken K6MR <k6mr at outlook.com>
To: "towertalk at contesting.com" <towertalk at contesting.com>
Subject: Re: [TowerTalk] tower/rotator woes...



Which is exactly the reason you need to torque balance an antenna. If your antenna is torque balanced, there will be -zero- torque on the mast in any wind condition. If you release the brake and the antenna windmills, you need torque balancing.

Properly balanced, there will never be a condition where the rotator cannot turn ?against the wind?, because there is no torque generated by the antenna(s) for the rotator to overcome.

Ken K6MR

##  I concur.  Fellow across town would destroy his t2X and ham-4  rotors.  He has a gross offset on the boom.   So I used the tq comp software on the K7NV Yagi stress program, to design the tq comp plate for the REF end of the boom.
He tested the yagi on a smaller  30 ft tower, with no rotor or coax.   It did not  wind mill in high winds.   He even climbed up there in a high  wind and could manhandle the yagi to another direction, and it would stay put.   So the
software works..as does the same program from DX engineering.   That was years ago, forgot all about it.  No more rotor failures as far as I know, but in his case, he has pushed the limits of the small rotors to the max. 
Dunno why ant makers dont include the simple tq comp plate, cost nothing to implement.  Then like steve sez, if more than one yagi on the mast, alternate sides when mounting the yagis. 

##  These days, id still start off with a decent rotor...and tq comp the various ants.   If u design the tq comp plate correctly, it requires very little tq to actually  turn an ant. 

Jim  VE7RF