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Re: [TowerTalk] When a Yagi Loses an Element

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] When a Yagi Loses an Element
From: W2RU - Bud Hippisley <W2RU@frontiernet.net>
Date: Sun, 03 Apr 2005 16:12:00 +0000
List-post: <mailto:towertalk@contesting.com>
In order of preference:
  1.  Hire KC1XX
  2.  Hire a crane
  3.  Disconnect guy wires and lay the tower over in the next windstorm
  4.  Follow my procedure below

I'm a little guy (160 pounds) and not particularly muscular.  Despite that, I 
owned a KLM 4-element 40 for a while, and I'd have to say the only way I could 
imagine replacing the reflector without a tilt boom/mast bracket such as the 
PVRC mount is to use a rope sling from a pulley or gin pole higher up the mast, 
as suggested by others on here, to support the boom while you slide the boom 
horizontally enough in each direction to temporarily remove the inner two 
elements one at a time.  (With my size, I'm always in favor of getting as much 
weight and as much torque off the antenna as soon as possible.)

Then, with two of the three elements gone, I'd try to continue the rope sling 
process until I had the remaining element in reach or at least until I had the 
center of gravity of the boom/element assembly right at the mast.  I'd follow 
K1TTT's suggestion to have a tag line to ground (or a lower person on the 
tower) from the end of the boom with no element on it.  At this stage, I'd also 
rotate the boom in the bracket until the element is vertically polarized.  
Re-tighten the boom-to-bracket bolts, re-position the rope sling (or use a 
second one), and make a failsafe knot around the boom between the tower and the 
element.  (Use muffler clamps or other U-bolts to stop the rope from sliding 
unexpectedly on the boom.)  Then completely disconnect the boom from the 
bracket and while supporting the boom/element monstrosity with the rope from 
the pulley above, roughhouse maneuver the whole mess until the boom is 
vertical, hanging alongside the tower, and the director is horizontal, wi
 th its boom/element bracket laying against the tower some number of feet below 
the top.  (The reason you go vertical polarization before this process is so 
the director will clear the upper guy wires and so someone a little lower on 
the tower can catch the end of the director as you're performing this little 
windmill stunt, after which they can then gently guide the rotation of the 
element tip past the tower the rest of the way.) 

At this point, the whole assembly can be slowly slid down the tower a few feet 
until you can conveniently reach and work on the end of the boom that's missing 
a reflector.  Tie the boom off in a few places to the tower, haul the reflector 
up and reinstall it, add a heavy-duty tilt bracket to your mast, do the 
windmill in reverse direction, put your two driven elements back on with the 
aid of the tilt-bracket, and you're in business.

See how simple that is?

Or, you can follow an alternate conclusion, as has been suggested by Steve, and 
do as I did, too -- sell the beam....

HTH.

Bud, W2RU

_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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