STEVE,
With apologies, I DISAGREE with your conclusion that it
"doesn't matter where the load is since it all turns into leg
compression at some point.
Horizontal forces (antenna / tower loading) are converted
to VERTICAL and HORIZONTAL components by Guy Wires
in Guyed Systems.
The ANGLES of the GUYS to the TOWER (or horizon)
are DIFFERENT for each set of guys in most systems
and therefore ANTENNA PLACEMENT WILL affect the
converted forces differently.
Tom N4KG
(RF Engineer who also had a couple of courses in simple mechanics).
On Thu, 23 May 2002 11:34:01 EDT K7LXC@aol.com writes:
> In a message dated 5/23/02 7:54:49 AM Pacific Daylight Time,
> swca@swbell.net
> writes:
>
> > > If I place 4 square feet at the mid point of the tower do I need
> to change
> > > what the top of the tower could hold?
> >
> > I have been dying to ask Steve this same question, since I think
> he said in
> > Dayton that "you just add it all up." My basic understanding
> makes me
> think
> > that 10 square feet halfway up a 100' tower is not the same as
> the same
> load
> > at the top of the tower.
>
> Jeez - you're asking a non-engineer?!? As I understand it, a
> typical
> tower spec is for the WHOLE tower so you can parcel it out anyway
> you want
> but it's also typically the headload on top that we normally deal
> with - it's
> also the 'worst case' loading. And, yes, things change when you move
> things
> around.
>
> Aside from the bending moment and other reactions, don't forget
> that the
> limiting tower spec is leg strength so it doesn't matter where the
> load is
> since it all turns into leg compression at some point.
>
> Cheers,
> Steve K7LXC
> TOWER TECH
> _______________________________________________
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> http://lists.contesting.com/mailman/listinfo/towertalk
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