VE9HF indicates his sched 80 mast is .25" thick. It's not.
IF his mast is typ 1.9" OD sched 80 stuff... it's only .200" thick. His
section modulus is only .412
If the yield strength is 35 ksi.... his max bending moment is only .412
x 35 ksi = 14,420 in lbs...[ 1200 ft lbs]
Lets say 7 sq feet @ 70 mph [20 lbs per sq ft] x 14' .... = 1960 ft
lbs of bending moment.
1960> 1200 ! The mast will snap like a tooth pick. The mast is maxed out
with 1200/140 = 8.57'
This doesn't even factor in the other TWO proposed yagi's... nor the wind
load of the mast itself !
It's NOT....." a serious tower" . It's made for TV ants'... and can
be used with ham ant's,
provided you don't overload it...esp with tall masts. Even if you guyed the
tower, the proposed mast you
are contemplating will fold over at a right angle. That Delhi isn't CSA
approved, nor does it meet
the Canadian S-37 tower specs. Load it up with heavy wet snow + a tiny bit
of ice .....+ a 55 mph gust
.. and it's bye-bye tower... plus 3 x ants' trashed. Removing a bent mast is
a gong show in itself.. and
extremely dangerous. If you want a stronger, self support tower, get a
Trylon Titan..[with the 48" wide bottom section]...
... or better yet ..a Trylon Super Titan. The Trylon super Titan IS a S-37
rated tower, and will handle 25 mm of radial ice + high wind.
It's the real deal. The stock Delhi top bearing plate + mating thrust
bearing is pure junk. The rotor plate is worse. You will end up
tearing up all the plates within months.
Later.......... Jim VE7RF
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