I was just correcting an error on your part. No need to get snippy about it.
I knew Sam very well and was an often visitor (and worker) to the "Swamp".
73, Dick, W1KSZ
> From: w2lu@rochester.rr.com
> To: towertalk@contesting.com
> Date: Wed, 27 Jan 2010 17:47:45 -0500
> Subject: Re: [TowerTalk] sched 80 mast
>
> Ok Dick, if it makes you feel better, I stand corrected.
>
> ---- Original Message -----
> From: "RICHARD SOLOMON" <w1ksz@q.com>
> To: "TowerTalk" <towertalk@contesting.com>
> Sent: Wednesday, January 27, 2010 3:55 PM
> Subject: Re: [TowerTalk] sched 80 mast
>
>
> >
> > I think that was W1FZJ and he said ..."if your antenna lasts through
> > the winter, it wasn't big enough"... .
> >
> > 73, Dick, W1KSZ
> >
> >> From: w2lu@rochester.rr.com
> >> To: towertalk@contesting.com
> >> Date: Wed, 27 Jan 2010 10:44:46 -0500
> >> Subject: Re: [TowerTalk] sched 80 mast
> >>
> >> How about repetitive gusts and possible resonance? But remember the Sam
> >> Harris / W1FZ philosophy - "If it stays up more than two winters it was
> >> over
> >> designed".
> >> ----- Original Message -----
> >> From: "Jim Thomson" <Jim.thom@telus.net>
> >> To: <towertalk@contesting.com>
> >> Sent: Wednesday, January 27, 2010 10:09 AM
> >> Subject: [TowerTalk] sched 80 mast
> >>
> >>
> >> > 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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> >> > TowerTalk@contesting.com
> >> > http://lists.contesting.com/mailman/listinfo/towertalk
> >>
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> >>
> >>
> >>
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> >
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> >
> >
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