[TowerTalk] FW: Max antenna weight

[Jim Thomson]

Date: Sun, 1 Nov 2015 17:01:32 -0600
From: "Matt" <maflukey at gmail.com>
To: <towertalk at contesting.com>
Subject: [TowerTalk] FW:  Max antenna weight

Hi Dave,

I don't recall where I got this from, but in some of my notes I wrote down
the following limits that were listed for a T2X:

Max vertical thrust: 1,000 lbs
Max boom:  45 ft
Max turning torque: 1,000 in-lbs
Max brake torque:  7,000 in-lbs

Hope this helps & good luck on your project.

Matt
KM5VI

## stating toque in inch lbs is fubar.  Do it in ft lbs, then
you can relate to it.  1000 inch lbs / 12  =  83 ft lbs..which is dick in the
real world. 

##  The trick here is to  torque balance the yagis before you install them.
Local ham converted his 204BA  to a 5 el yagi,  with els bunched up at one
end.  He then mounted it at the balance point. IE: CG.   The TQ on the poor
T2X  was beyond wicked, he trashed two of them.  I used K7NV tq compensator
software and designed  a TQ  compensation plate  down at the REF end of the boom.
The yagi was then placed on a short 30 ft tall tower to test the concept. No rotor used,
just a pair of thrust bearings.  It was free to windmill all it wanted.  In a windstorm, it
did not budge.  The owner then climbed the 30 ft tower in a windstorm, and could 
easily turn the yagi in any direction by hand..and it stayed put.    With the plate
removed, it would immediately windmill...like a weather vane. 

Jim   VE7RF