[TowerTalk] Stepir Repair

[Kimberly Elmore]

That's a possibility. It's not a cover for DXing, though it *is* a pretty good location for it! We've had other problems that we haven't yet diagnosed. We use a Yeasu 2800DXA rotor. Earlier (before my name was associated with it) we suffered a shear bolt failure, which allowed the antenna to freewheel and destroy the cabling. The shear bolt was found to be too soft a grade, so it was replaced with a grade 8 bolt. Something has failed again, because it's freewheeling once more. According to the guys that set this up 10 y ago, everything is supposed to be over-engineered by a factor of 50%. When we get up there, we'll find out of the rotor has failed or if it's the shear bolt again. Either way, we need to solve that problem, too. It's at the top of a large building (https://en.wikipedia.org/wiki/National_Weather_Center has a picture) and we're not sure what sort of shock loads the winds can create on the antennas at the top of the spire. When I've watched it on windy days, I've never seen anything out of the ordinary. 
Kim N5OP

      From: Wilson Lamb <infomet at embarqmail.com>
 To: towertalk at contesting.com 
 Sent: Monday, December 5, 2016 6:00 AM
 Subject: [TowerTalk] Stepir Repair
   
I wouldn’t put that many moving parts and fiberglass material in such a difficult location.
You don’t need spectacular performance, so I’d go for the most durable solution with the fewest things to fail.
There’s lots of experience re wind survival here on the group and I’m sure they would be glad to share.
A Tennadyne, maybe six or eight elements would do what you really need.
Perhaps they would be willing to beef up the elements a bit?
If you could assure maintenance of fatigue life, welding the joints would be nice.
It’s a radical idea, but some study of performance might show that a lower installation would accomplish your objectives with less maintenance liability.
The first step would be deciding to whom you want to talk.  If it’s all a cover for DXing, that’s another matter....
Out on a limb, as usual,
WL
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