>How strong is strong?
>
>I have had a 2 1/2" schedule 80, 21 foot long piece of pipe stored for years
>hoping someday to use it for a mast. I measures just under 3" OD and weighs
>166 lbs. Just standard schedule 80 galvanized pipe. A real beast.
DO NOT USE ANT TYPE OF WATER PIPE FOR LONG MASTS! Schedule 40 or 80 are
not designed to handle antennas in strong bending moments caused by wind.
No matter how big it appears it will bend! I used schedule 80 before I
knew and it bent in the first major wind and all I had was a 2el Mosley 40
with a 4el Swan/Hornet Tri-bander 9 feet above.
I worked as MIS Director at a major Heating/Plumbing supply in the late 70's
and I got charts on both EMT and water pipe. Both are terrible for any
antenna application! Lou Tristao sent me a chart on the masts he made
specifically for stacking yagi's and the only place you should (or could)
use Schedule 80 is with a beam just above the top of the tower.... as very
little of the mast is exposed to bending moments.
Try something else and save yourself the grief!
Dave K4JRB
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