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[Towertalk] Mounting fixed antennas

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Subject: [Towertalk] Mounting fixed antennas
From: (Steve Katz)
Date: Wed, 14 Aug 2002 14:57:05 -0700

> At 02:02 PM 8/14/02 -0700, Steve wrote:
> >Of course, I've been there, and done that, too (small tower leg, large
> plate
> >and U-bolts) but all I do is shim the tower leg with steel angle iron.
> That
> >not only increases its "diameter" to two inches (as the beam wants) but
> also
> >provides a nice, flat (not round) mounting surface for the plate.  The
> angle
> >iron pieces cost about $2 at Home Depot...
> Yes, but this also has the effect of concentrating any loads contributed
> by 
> the fixed yagi on one leg of the tower, which doesn't strike me as a very 
> good idea.  I can't do the math to analyze how much better it is, but if
> it 
> were me, I think I'd figure out a way to put the load into at least two 
> legs, preferably all three.
        [Steve Katz]  Hi Pete.  I agree I wouldn't use one leg of a Rohn 25G
to support a 60' long 20m beam; but, then, I wouldn't use a 25G to support
this on top with a thrust bearing, either.  Common sense prevails.  I've
side-mounted (one leg) 36' long HF beams on 45G with no ill effects noted
after 15-20 years, so that seems to work.  I've also side-mounted (one leg)
24' long VHF beams on 25G, also good results.  Haven't popped a weld or bent
a section yet.  Murphy's Rule of Thumb: If, when you're doing it, it seems
really stupid, it probably is. -WB2WIK/6

> 73, Pete N4ZR
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