I think it would be useful and beneficial
for writers to:
CHANGE the SUBJECT LINE to reflect
the CONTENT of the MESSAGE BOX
Tom N4KG
On Sun, 22 Sep 2002 "Bill Hider \(N3RR\)" <n3rr@erols.com> writes:
> I use Spiral Vibration Dampers on my guy wires.
>
> Photos are on my website: www.erols.com/n3rr
> Click on: "Guying Subsystem"
>
> Bill, N3RR
>
>
> > >
> > >> There are some curious doodads installed on the guys. A clamp
> > >> around the cable and a colinear pair of cylinders about 10"
> long,
> > >> parallel to the cable, and a tad more than the cable diameter
> away.
> > >> The cylinders have rounded ends and show evidence of arcing.
> > >
> > >
> > > These are "stock bridge dampers' they are the mechanical
> equivalent
> > >of an antenna tuner, reflecting energy (of a particular
> frequency) back
> > >up the cable when the cable is vibrated, based on the distance
> from the
> > >cable end, the thickness of the guy cable and the weight of the
> lead
> > >weights. Or if you prefer:
> > >They change the impedance of the anchor end of the cable.
> > >They dampen the high frequency vibrations, like a strummed
> string.
> >
> >
> > Vibration dampers can be seen more commonly on high-voltage power
> lines.
> > Mounted close to the tower ends of the power line conductors
> and/or on the
> > overhead ground wires (which run from tower top to tower top),
> these
> > dampers, and those on tower guy wires, absorb the wind-induced
> vibrations
> of
> > the conductors, preventing the wires from fatiguing and breaking
> apart.
> > Seen from the ground, the power line dampers look like dumbells
> hung
> > underneath the wires.
> >
> > As an aside on the issue of vibration dampening, one might also
> see
> metallic
> > or plastic rectangular _flags_ in the middle of long spans of
> outdoor
> > telephone cables. These are spoilers used to prevent the
> loosely-suspended
> > telephone cables (vs the high-tension power lines) from
> _galloping_ under
> > certain conditions of temperature (hence wire tension) and wind
> speed.
> > Without these spoilers the cables will bounce around like a
> child's
> > jump-rope in the wind, also causing fatigue and breakage.
> >
> >
> > >
> > > 73 (= Best Regards) de: Ron ka4inm@tampabay.rr.com
> > > 100% LINUX, since July, 1997 SENT Time and Date are UTC
> > > Visit my HAM Web SITE at: http://www.qsl.net/ka4inm
> > >
> >
> > 73 de
> > Gene Smar AD3F
> > >_______________________________________________
> > >Self Supporting Towers, Wireless Weather Stations, see web site:
> > http://www.mscomputer.com
> > >Call 888-333-9041 to place your order, mention you saw this ad
> and take
> an
> > additional 5 percent off
> > >any weather station price.
> > >_______________________________________________
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> > >http://lists.contesting.com/mailman/listinfo/towertalk
> >
> > _______________________________________________
> > Self Supporting Towers, Wireless Weather Stations, see web site:
> http://www.mscomputer.com
> > Call 888-333-9041 to place your order, mention you saw this ad and
> take an
> additional 5 percent off
> > any weather station price.
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> _______________________________________________
> Self Supporting Towers, Wireless Weather Stations, see web site:
> http://www.mscomputer.com
> Call 888-333-9041 to place your order, mention you saw this ad and
> take an additional 5 percent off
> any weather station price.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
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