Aluma Towers in Fl has "guy ears" at the top of each section and mechanical
stops to take the
tension off the cable. I have a HD75 and have never use the guying, A lot of
there towers are sold
to the cell industry on trailers for cell site evaluations so I guess that
might be where the guys
might be used.
73 Larry K1ZW
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim
Lux
Sent: Monday, February 26, 2007 8:56 PM
To: richard@karlquist.com; kdurand@protologiceds.com
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Crank up / guy wires..
At 04:14 PM 2/26/2007, Rick Karlquist wrote:
>Guyed crank ups used to be available until the 1970's.
>The advantage of guying is that the base is much smaller and the tower
>can be a lot lighter for the the same windload. To really take
>advantage of guying, some towers had locks that took the stress off the
>raising cable after the tower was cranked up. It is not entirely clear
>why they stopped making them, but the unpopularity of guys due to
>XYL/neighbor complaints was probably a factor.
The engineering of a guyed crankup is also a bit complex, especially if the
guys attach on the
extending part. There's that whole bending vs compression loads thing. It's
possible that with newer
standards, it's not cost effective to make one strong enough, or that the
complexity and strength of
the locks raises issues, in a "residential" kind of application.
They still do exist: I have seen recently manufactured guyed crankups in a
tower trailer
configuration, but it's a pretty big structure (45m tall when erected) with
hydraulic assists, etc.,
and can hold a fairly good sized antenna up on top. Way out of most ham
budgets.
(google for "MOSS tower radar" or "Moghaddam tower radar")
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