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[Towertalk] Box forSPG and Lightning protectors

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Subject: [Towertalk] Box forSPG and Lightning protectors
From: n3rr@erols.com (Bill Hider (N3RR))
Date: Sun, 22 Sep 2002 08:45:04 -0400
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
> >_______________________________________________
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> _______________________________________________
> 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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