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
From: Roger (K8RI) on TT<mailto:K8RI-on-TowerTalk@tm.net>
Sent: Monday, February 20, 2017 8:31 AM
To: towertalk@contesting.com<mailto:towertalk@contesting.com>
Subject: Re: [TowerTalk] tower/rotator woes...
Possible, but unlikely.
Even drastically overloaded with the large array I had up, in wind the
Ham IVs would be unable to turn the array, but they never bound up. A
few times, the antennas would rotate all the way to the stop with the
motor unable to apply enough torque to stop the rotation, but again,
they never bound up. The tail twister is just a beefed up version. With
the brake released, I could apply enough force by hand to turn the mast.
That was the number one reason I dislike rotators with wedge brakes
with tiny motors (cheap) and a very high ratio spur gear train stamped
from sheet metal.
If the wind overpowered the motor, you didn't dare engage the brake
without the danger of damage.
73, Roger (K8RI)
On 2/19/2017 8:22 PM, Ken K6MR wrote:
> Most crankups have a sufficiently large sleeve in the top that the shim is
> not really necessary. We are talking 1/32” here. Even the sleeve in the Rohn
> pointy top sections is spec’d at 2.08 I.D. (1/32” = 0.0313”). That’s way more
> than necessary to allow for the eccentricity that would be present when using
> a 2” nominal mast.
>
> My guess at the original poster’s problem is unbalanced torque present under
> windy conditions. Bencher seems to be the only tribander that includes a
> torque compensator in their design.
>
> Ken K6MR
>
>
>
> From: john@kk9a.com<mailto:john@kk9a.com>
> Sent: Sunday, February 19, 2017 4:39 PM
> To: towertalk@contesting.com<mailto:towertalk@contesting.com>
> Subject: Re: [TowerTalk] tower/rotator woes...
>
> Many years ago when I had a small tribander at my parent's home, I had a Ham
> IV and I shimmed the clamp because I used a water pipe mast which was 1.90
> OD. I have not used that style rotator since then and I was surprised to
> look at the manual today and see that the T2X was designed for a 2 1/16
> mast. Who uses this size? This seems like a poor design and at a minimum
> they should include a shim pack. How many people are properly using shims
> with Hy-Gain rotators?
>
> John KK9A
>
> Re: [TowerTalk] tower/rotator woes...
> from [Kim Elmore] [Permanent Link][Original]
> To: DAVE WRIGHT <kanives@yahoo.com>, towertalk@contesting.com
> Subject: Re: [TowerTalk] tower/rotator woes...
> From: Kim Elmore <cw_de_n5op@sbcglobal.net>
>
>
> I had a similar problem because and must, with some embarrassment, admit
> that I was careless and did not shim the rotor as I should have. The T2X is
> made to accommodate a 2 1/16" OD mast. My mast is a galvanized steel 2" OD
> and for yeas, I couldn't figure out why my T2Xs kept failing. I listened to
> it and heard it bind, then carefully read the manual *again* and saw that --
> Lo! and Behold! -- the T2X is designed for a 2 1/16" OD mast. I purchased
> some 1/32" aluminum sheet metal and placed in in the cradle of the T2X
> and... No more binding! The rotor now turns freely. The T2X is a very tough
> rotor; chances are, this will fix your problem.
>
> Kim N5OP
>
> _______________________________________________
>
>
>
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--
73
Roger (K8RI)
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