[TowerTalk] t2x, c31xr and ef240x

[Pete Smith]

At 06:59 PM 9/1/1999 -0500, brunet@us.ibm.com wrote:
>
>
>
>Ty says...
>
>
>No, incorrect. It's not nearly that simple to calculate and has little to
do the
>turning radius.  It has to do with moment arm for each significant piece.
You
>can essentially eliminate the mast since it's moment is close to zero.
Figure
>things for the two antennas and add them and that'll give you the true torque
>load
>
>However, I can tell from experience that a T2X will easily handle that load.
>
>73, Ty K3MM
>
>Pete says:
>
>Interesting.  I see for the C36XR the mast torque is spec'd at only 120
in-lbs
>or 10 ft lb, but the weight is 108 and the turning radius is 29.2' or 3154
ft lb
>so it appears that, as you say, it is not as simple as multiplying the radius
>and weight.

IMO, the notion of "effective moment" being weight times turning radius is
a misnomer.  As Ty says, the true effective moment is the sum of all the
moments.  At least the Hy-Gain figure has the virtue of being conservative,
because it represents an antenna that has all its weight at the maximum
distance from the mast.

Force 12's maximum mast torque figure refers to wind-generated torque, and
as such is only relevant to brake ratings and to the special case where
you're trying to turn the rotator directly against the current wind.

73,  Pete N4ZR
Sometimes a tower is just a tower

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