[TowerTalk] Guy wire / Phillystran vibration

[Scott R.]

Towertalkers:

Question about guy wire vibration.  K4JNY and I were doing tower work
at his place all day Sunday and have noticed that on our 120’ Rohn 45
that we are experiencing quite a bit of vibration to the tower and guys
that we believe is being transmitted down the tower by the 4 el 40m
beam at the top.   This vibration occurs at wind speeds of 10 mph or so
or higher.  

Jeff’s first thought was that guy wire tension was too high, but
checking with the tension gauge resulted in only 2 of the 9 being too
tight – loosening them didn’t seem to mute the vibration on them much. 


The guys are EHS at the 40’ level, and EHS for the bottom third and
Phillystran top two thirds for the guys at 80’ and 120’.  

Our concern is that the Phillystran is not going to respond well,
long-term, to vibration.   Can excessive vibration be an early failure
problem for Philly guys?  

Any other concerns with this situation we should be aware of?   Aside
from the loosening of connections, antenna hardware, etc. –  our
concern is for the tower and the guys itself.

TNX 
Scott W4PA


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"Time you enjoy wasting is not wasted time." --
Bertrand Russell

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