[TowerTalk] What rotor should I use

[David Gilbert]

Just look at the physics of it.  Whipping of the elements represents 
stored energy, just as in a spring.  If that energy is released at the 
end of travel it adds to the momentum of the elements that would 
otherwise be due only to their mass.  I'm not saying that aluminum 
elements don't whip, but any antenna with lots of whip is going to put 
more stress on a rotator than an antenna with less whip ... assuming the 
masses are equivalent.

By the way, given the material properties of fiberglass versus aluminum, 
and without knowing the exact figures, I wouldn't be surprised to learn 
that fiberglass elements also have more mass than comparable aluminum 
elements.

73,
Dave   AB7E



On 6/27/2013 9:38 AM, Steve Dyer wrote:
> Any large beam, fiberglass tube or aluminum is going to potentially whip in wind. I've never seen any compelling evidence a SteppIR causes any more forces at the rotator than an *equivalently* sized Al beam.
>
> 73,
> Steve
>
>
>
> ________________________________
>   From: Joe Nuccio <k4nyy at yahoo.com>
> To: Chris Pinholster <k4win at mac.com>
> Cc: "towertalk at contesting.com" <towertalk at contesting.com>
> Sent: Thursday, June 27, 2013 5:29 AM
> Subject: Re: [TowerTalk] What rotor should I use
>   
>
> Hi Chris,
>
> Thanks for the input and your experience.
>
>
> The concern seems to that the 36' elements on the SeppIR start 'whipping' back and
> forth while the antenna is being rotated which puts a lot of stress on the gears when it
> comes to a stop. Apparently, this 'whipping' action is not of a concern on large beams
> made out of aluminum.
>
>
> 73,  Joe  K4NYY
>
>