[TowerTalk] Rohn HDBX48 failure

[Steve Maki]

K8RI wrote:

> One thing I forgot to add in a previous post about rotors mounted down in a 
> tower.  When mounted "in the tower",  but at the base there is no give to 
> take up the stress and that small area takes the entire brunt of the torque. 
> If the rotor has a mount on the concrete, or a seperate mount it removes the 
> stress from the tower.

Actually, there's a lot of cushion provided by a long
mast.

I had an extended guyed 72' HDBX style tower in the 60s,
with the rotator a couple feet off the ground, rotating
a 4 el tri-band quad through 70' of 1-7/8" OD pipe. I
was amazed at the almost 45º twist in that mast in high
winds. It was ridiculous, really. I should have used
a 2-1/2" or 3" mast on that one.

Steve K8LX