[Towertalk] Rope

[Wendell Wyly W5FL]

In Texas there is no such thing as a (long term) self supporting tower.
Those that go to 60 feet self supporting have a base nearly 8 feet on a side
and I have seen the legs bent in those.

Do the calculations yourself and you will NOT put up a Rohn tower 35 feet
above a house bracket with even a TV antenna on it.  At 50 feet total tower
height you NEED at least TWO sets of 3/16 guy wires tied to three or four
2x2x2 foot guy anchor set 1 foot under the top of the soil (on a 35 foot
radius to the tower )and a 4x2x2 foot footing for the tower itself with the
first section set 4 feet in the concrete base.  This includes one 1/2 inch
and one 7/8 in coax with a 6 sq ft antenna with NO icing on the tower and 30
psf wind pressure.  That is just like the Rohn catalog shows also for the
lowest wind rating areas (70mph).  I have over 70 mph winds almost every
year and this is a rated 70 mph area.  My tower is designed for 100 mph.

That is a good gin pole.  I use 1/2 inch diameter trucker rope - but don't
allow it to be left outside or it will deteriorate rapidly.  Don't use Nylon
as it stretches too much.  Good manilla rope works well.  Rope should not be
used over 10% of it's listing breaking strength and that is for NEW rope.

The type house bracket that Rohn used to base their designs on applies more
to buildings than to houses.  The pull out loads must be very high and the
eves of most house will not be satisfactory as they are not structural by
any stretch of the imagination.

-----Original Message-----
From: towertalk-admin@contesting.com
[mailto:towertalk-admin@contesting.com]On Behalf Of Julio
Sent: Sunday, May 05, 2002 10:54 AM
To: towertalk@contesting.com
Subject: [Towertalk] Rope


I have a Rohn EF2545 gin pole and I need to replace the rope. What would be
the recommended type and size to use?

In some of the older Rohn catalogs I think I read that Rohn 25G could be
self supporting at 35' above a house bracket. I don't see that specification
in the new catalogs. My intent is to install a 5 elem. M2 6m beam ( about 2
Sq Ft on an 18' boom ) just to get me by for the summer Es season. Does
anyone take exception with the 35' above the house bracket spec?

Julio, W4HY


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