On 7/20/2016 17:26 PM, Bill Tippett wrote:
K8RI: > A heavy duty rotator with a large antenna should be mounted well
down into the tower. Mounted at the top, in the tapered section would
likely put very high stress at that point.
I mounted my rotator at the same point in 45G and had no problems for >10
years with the antennas/wind speeds in Colorado described previously. If
still concerned, you could mount a straight 25G section above a straight
25AG4 and install the rotator in the 16" window. Of course this would
require a long mast (~15'). I don't know which LPDA Jeff is considering
but I doubt it's >32 sq. ft.
And besides, the rotational torque will be resisted by z-braced sections
below the rotator.
The only concern with the normal R25 rotator mounting position is
lateral loads encountered with tall masts. I've seen pointy top sections
fold over in that scenario.
-Steve K8LX
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|