> 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
>
> Check out the World HF
> Contest Station Database at
> www.pvrc.org
>
>
>
>
> _______________________________________________
> Self Supporting Towers, Wireless Weather Stations, see web site:
> http://www.mscomputer.com
> Call 888-333-9041 to place your order, mention you saw this ad and take an
> additional 5 percent off
> any weather station price.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
|