In a message dated 98-10-13 04:09:48 EDT, JSheinb785@aol.com writes:
> >>
> I've been using schedule 40 galvanized water pipe (1.93" OD) for 20 years
> and
> have never had a failure. I've had over 10 ft. out the top of the tower (
> with
> a thrust bearing, of course) with a 2 meter 12 el beam atop, a 1015 Hygain
> duobander in the middle and a 20 mtr monobander 2 ft above the thrust brg.
> So
> why the fuss over throwing away extra money on an Aluminum mast or a
chrome-
> moly steel tube?
Yikes! Well, every time you speed you don't get a speeding ticket either.
With Nueces county a 95 MPH windspeed zone and being within 100 miles of
hurricane oceanline, you've got yourself quite a handful. The MARC Program
calculates 32,908 in-lbs of bending moment and recommends a 65K psi yield
strength mast with a 0.250" wall. Your water pipe has less than 30K psi yield
strength if it is rated at all.
Congratulations for dodging this bullet so successfully for years. For
any other TowerTalkians interested in reliable tower/antenna system
installations - DO NOT TRY THIS AT HOME.
Cheers, Steve K7LXC
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