[TowerTalk] Attaching Large Antennas to Rohn-45 Legs
K7LXC@aol.com
K7LXC@aol.com
Sun, 24 Jan 1999 10:12:54 EST
In a message dated 99-01-23 23:10:43 EST, ve6jy@freenet.edmonton.ab.ca writes:
> > I have a 8/8 stack to Europe for 10 meters on 48' booms. I'm also putting
> > up 7/7 for 15 meters on 48' booms. I'm wondering what type of boom to
leg
> > arrangement to use. I'm leary of tightening a u-bolt too tight around
the
> > tower leg. My thought now is to use 4 U-bolts on the tower leg for each
> > antenna. Any other advice?
>
> I'd be more than leary...... the towers I have are all heavier than Rohn
> 45 and I wouldn't consider mounting anything on just one leg - that just
> can't help but weaken the leg and contribute to an even worse scenario.
Don, I've seen the photos on your web site and the hardware and all is
very impressive.
I'm not sure how it's going to 'weaken' the leg. We're not talking about
tightening the U-bolts until they crush the leg. The antennas Bill's talking
about are well within the compressive leg force that'll be on the legs.
> A couple of angle or channel brackets going along the face of the tower,
> perhaps 2 feet apart will distribute the forces in a much better fashion.
Of course this is a better scenario. Or use a big plate fastened to the
legs (might be excessive area - a 2 foot by 2 foot piece has 4 sq.ft. of
windload). Either way the load is on two legs and not one.
I was responding to his question about "boom to leg" attachment. By using
side boom struts and a truss, you should be able to transfer just about all
the weight and wind torque to several places on the tower rather than just the
U-bolts on the leg (not recommended by itself). That would work for me.
Cheers, Steve K7LXC
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