[TowerTalk] Broken Element Tip

[K7LXC at aol.com]

In a message dated 5/11/04 9:17:01 PM Pacific Daylight Time, 
ve5ra at sasktel.net writes:

> The tip of the reflector on a Force-12 6L 10M yagi (EF-610) broke off
>  right at the rivet.  The tip is 0.375" OD dia and 44.375" long and fits
>  into the next larger 0.50" dia section.  I suspect that it vibrated until
>  it fatigued and then fell off.  Force-12 does not mention that dampening
>  rope is needed in the element tips so none was installed.  With such a
>  small diameter of 0.375", 1/4" rope would probably not fit....maybe string
>  would work to act as a dampener?
>  Has anyone had a similar case and if so what did you do to prevent the
>  element tip from vibrating again?

    Here's what I recommend. In addition to the standard 3 rivets inline for 
element attachment, add a second row of 3 (or 4) rivets opposite the original 
ones. Or add a third row so that each row is 120 degrees around the element. 
You'll be good to go for years now.

    The problem is that with only the single row of rivets there's still lots 
of slack in the element pieces, enough for the element to work itself back 
and forth and then down to the ground. Two or even three rows of rivets will 
totally eliminate the wind working on the element and you'll never have to worry 
about it again.

Cheers,
Steve    K7LXC
TOWER TECH -
Professional tower services for commercial and amateur
Cell: 206-890-4188