I guyed an 80 ft TV tower at 4 levels and another 75 footer at 3 levels.
I can't imagine guying 70 ft of R45 at 4 levels. Maybe 3 for a really
strong installation, otherwise 2 levels should be adequate for most
applications. Didn't K7NV indicate that making the TOP guy heavier
would also allow a slightly higher load on Top?
Tom N4KG
On Tue, 1 Oct 2002 "Stan & Patricia Griffiths" <w7ni@easystreet.com>
writes:
> If you guyed a 70 foot 45G at 4 levels and put the top set at the
> top, it would hold a HUGE load. I can't calculate how much since I am
not
> an engineer, but you should find one and suggest this configuration to
> him. You will be very surprised at how much it will hold . . .
>
> Stan
> w7ni@easystreet.com
>
> ----- Original Message -----
> From: "Michael Tope" <W4EF@dellroy.com>
> To: <towertalk@contesting.com>; "Chuck Counselman"
> <ccc@space.mit.edu>
> Sent: Monday, September 30, 2002 1:06 PM
> Subject: Re: [Towertalk] 45G (guyed) vs. SSV (self-supp'g) 70-ft.
> tower
>
>
> > I will probably get flamed for this, but I can't resist. Aren't
> those Rohn
> > specs for 45G super conservative (8sq ft at 90 MPH) because they
> > place the top set of guys so far below the top of the tower? I
> would
> expect
> > that a properly guyed 70' x 45G tower would be capable of holding
> up
> > 20 sqft+ in a 90 MPH wind if the top set of guys were placed
> reasonably
> > close to the top of the tower. For that reason alone I would go
> with the
> > 45G tower. On the other hand, getting antennas on and off the
> guyed tower
> > is a little more work (tram line) versus straight up and down.
> Also if you
> > are interested in vertically stacking antennas along the length of
> the
> tower
> > you have the problem of guy wire interaction to worry about. This
> can be
> > solved by going to Kevlar or Fiberglass guys, but I think it adds
> to the
> > cost (versus steel guys):
> >
> > Rohn 45
> >
> > PROS
> > Smaller base
> > Larger antenna windload capacity - 20sqft (with properly
> engineered guy
> > system)
> > Fall zone probably smaller (heaven forbid)
> >
> > CONS
> >
> > Steel guy wires need to be broken up or replaced with insulated
> material
> > Tram line needed to remove/install antennas
> > Guys vulnerable to falling trees and vandalism (kevlar vulnerable
> to fire)
> > Probably less appealing to neighbors
> >
> > SSV Tower
> >
> > PROS
> >
> > Antennas easily hoisted up and down
> > No Guy wires and guy wire electrical interaction
> > More appealing asthetically (to non-hams)
> >
> > CONS
> >
> > Lower windload capacity
> > Larger concrete base
> > Probably has (or a least potentially has) a larger fall zone
> >
> > That is the trade space as I see it, Chuck. I would probably
> > opt for the 45G if it were me.
> >
> > Good luck!
> >
> > 73 de Mike, W4EF.............................................
> >
> > ----- Original Message -----
> > From: "Chuck Counselman" <ccc@space.mit.edu>
> > To: <towertalk@contesting.com>
> > Sent: Monday, September 30, 2002 7:15 AM
> > Subject: Re: [Towertalk] 45G (guyed) vs. SSV (self-supp'g) 70-ft.
> tower
> >
> >
> > > At 8:59 AM -0400 9/30/02, K7LXC@aol.com wrote:
> > > >In a message dated 9/29/02 8:48:19 PM Pacific Daylight Time,
> > > >ccc@space.mit.edu writes:
> > > >
> > > >> Can anyone give me an estimate of the overall cost of each
> > > >> alternative (45G or SSV), considering not only the tower
> itself but
> > > >> also the foundation work, professional erection, and guying
> (for
> the
> > > >> 45G)?
> > > >>
> > > > > In other words, what's the net cost of doing without guys?
> > > >>
> > > >...You can gather the steel costs yourself - check Texas Towers
> or
> other
> > > >Rohn dealers.
> > >
> > > I'd already done that. The difference in steel cost is not
> > > significant. The _erection_ of a 70-ft. SSV tower is what
> worries me.
> > >
> > >
> > > >...if you want the least expensive 100' antenna structure and
> > > >have the real estate and spousal approval, you can't beat a
> guyed
> system.
> > >
> > > I know that a guyed system is cheaper, but by how much? $3k,
> $30k,
> > > or what? Just approximately.
> > >
> > > I'm short on real estate. Guy anchors would have to go in the
> > > "setback(s)" of my lot. Obtaining zoning approval may be
> difficult
> > > and could force me into compromises that I want to avoid.
> > >
> > > -Chuck, W1HIS
> > >
> > >
> > > _______________________________________________
> > > AN Wireless Self Supporting Towers at discounted prices,
> > > See http://www.mscomputer.com
> > >
> > > Wireless Weather Stations now $349.95. Call Toll Free,
> > > 888-333-9041 for additional information.
> > > _______________________________________________
> > > Towertalk mailing list
> > > Towertalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > >
> >
> >
> >
> > _______________________________________________
> > AN Wireless Self Supporting Towers at discounted prices,
> > See http://www.mscomputer.com
> >
> > Wireless Weather Stations now $349.95. Call Toll Free,
> > 888-333-9041 for additional information.
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
> _______________________________________________
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
>
> Wireless Weather Stations now $349.95. Call Toll Free,
> 888-333-9041 for additional information.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
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