[Towertalk] Hy-Gain 204BA Rattle

[K7LXC@aol.com]

In a message dated 11/12/02 9:25:29 AM Pacific Standard Time, ve2dc@rac.ca 
writes:

> The rope has nothing to do with rattles...
>  
>  Something is amiss with your installation...

    Umm, not exactly. The 'rattling' is generally due to low-windspeed 
induced element vibration - it goes away when the wind speed increases. 

    The constant vibration causes metal fatigue and element failure. One way 
to minimize the vibrations is to damp the element with something that changes 
the frequency; one of the time-tested ways is to add rope inside the 
elements. Yes, it does work.

    The more current thinking is best exemplified by the Force 12 element 
designs which use an aggressive element taper schedule (it goes from big to 
little very quickly). This not only eliminates the low windspeed vibration 
but also allows for smaller, lighter elements. 

Cheers,
Steve     K7LXC
TOWER TECH -
Professional tower services for commercial and amateur