[TowerTalk] "Coax Break-In".. Applauded!

[Paul Terwilliger]

On Tue, 5 Aug 1997 07:01:31 -0400 (EDT), W3LPL wrote:

>At W3LPL, we follow an annual element rotation policy, much like tire
>rotation on your pick-up (for you little pistols: automobile).  Of
>course, the implementation of this policy is assigned to one of the
>rookies from the last operating season.  When the rookie has finished
>rotating all of the elements, he finishes the job by simply flipping the
>48 foot boom around and the job is done (on that Yagi) until next year!
>The only problem with this element rotation policy is that after one of
>the rookie has finished doing all of Yagis here in a busy weekend, he
>truely appreciates the true meaning of "Mega Hertz" and "floppy disk." 
> 
>An example for one of my 6 element 15M Yagis, simply swap the pairs of
>elements shown, then flip the boom:
>
>x--------->  ----------------------  Reflector
>x
>x  y------>   --------------------   Driven Element
>x  y
>x  y  z--->    ------------------    Director 1
>x  y  z           
>x  y  z--->    ------------------    Director 2
>x  y  
>x  y------>    ------------------    Director 3
>x
>x--------->    ------------------    Director 4
>
>73
>Frank
>W3LPL

Um, Frank, you're doing this all wrong.

You need to balance the wear on the *electrons* in each element.  So
since the DE has the highest current and D4 (probably) the lowest,
they should be swapped.

Or better yet, use the antenna current info from your modeling program
to work out a more equitable deal.  And best of all, would be to put a
watt-hour meter on the feed to each antenna so you know *exactly* when
it's time to rotate elements.

Of course, when you do the rotation you also give each element a 1/2
turn, right?  Evens out the bird poop.

73,
Paul, K1TI


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