> ----Original Message Follows----
> From: wf3h@comcast.net
> To: TowerTalk@contesting.com
> Subject: [TowerTalk] Guying a tiltover tower
> Date: Fri, 29 Apr 2005 19:34:10 +0000
>
> I'm looking at erecting 70' of Rohn 25 with a Pro 67B at the top. This
will
> have no thrust bearing, and the antenna will be <1 foot above the tower.
>
> I'd like to put up a tiltover, tilting from the base, rather than a
> foldover. Towers I've seen that are tiltovers are usually guyed
differently
> than non-tiltovers. Any suggestions or references about guying?
>
> How about mechanisms for tilting? Anybody have good ideas on how to
actually
> tilt the tower?
>
> Thanks all
>
> Bob/WF3H
Bob, you can do it but it isn't straight forward. The late, great Gerry
Mathis W3GM used a "falling derrick" method to tilt over 100' of 25G with
large arrays attached. I have a very bad slide that shows the derrick tower
that normally rested on a winch bracket I could forward it to you, but it
doesn't show very much detail. I've quoted a Towertalk message below for
your reference. If you search "W3GM" in the towertalk archives, you'll find
other messages concerning the use of this technique. I personally used it
at his QTH on several occasions and can attest to the fact that it works
well, and sure beats climbing a 100 footer in a March snow storm to fix a
stuck rotor! I'd suggest you contact someone from the Frankford Radio Club
as I understand there might be other members who currently employ this
method, and may have plans.
quoted from a message posted on 29 March 2004, by Jim Jarvis, N2EA:
"Gerry Mathis, W3GM, used a slightly more formal version of
this system with multiple 100' rohn 25 towers at his station.
The towers were guyed 4 way instead of 3, and the "back" guyset
was attached to a horizontal run of 25G which was 3 or 4 sections
long.
He fabricated a mating, hinged section for the tower base, such
that the main tower and the derrick tower were tied together and
the assembly tilted over.
A dead man and winch was installed at the point where the derrick
tower came to ground. Gerry drove this winch with a 1/2" electric
drill. It took him about a half hour to raise or lower the tower,
given the gearing, but it was amazing to watch a guy almost 80 years
old singlehandedly repair his 40m beam by laying it over.
There is a published design to keep the beams horizontal during layover,
by the way.
At least two members of the Frankford Radio Club use Gerry's scheme
on their 100' towers today."
73, Tom Hybiske K3GM
_______________________________________________
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.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|