I don't think anyone except a PE can tell you if this is safe. My 70' tower
in Aruba has more wind load than yours and a smaller guy radius, however I
used Rohn 55g and also 5' high guy posts. Since there will be added stress
using the smaller guy radius you will be safer using a stronger tower and
larger guy wires than standard. It is certainly possible to engineer a
system that will work for you.
John KK9A / P40A
To: towertalk@contesting.com
Subject: [TowerTalk] Shortened Guy Leads On R25G
From: "jknodel M Knodel" <jknodel@msn.com>
Date: Mon, 23 Oct 2006 12:55:07 -0700
List-post: <mailto:towertalk@contesting.com>
Thanks for the help with my previous questions regarding the crankups. Here
is my next question. I would appreciate any thoughts I could get on it.
I am planning on putting up a 60' (actually about 61.5' with the BPL25G top
thrust bearing plate) Rohn 25 tower. I will have one 3 element SteppIR beam
with the 30/40m dipole option on it. This antenna is 8.1 sq. ft wind load
and will be placed just a couple inches above the thrust bearing (no long
mast on top). The 60' tower is rated at 10.2 sq. ft. windload for 90 mph
(my area windspeed).
I would like to place the downguys at a shorter distance than the 80%
spec'ed by Rohn. I surveyed my property and calculated (with AutoCAD) that
I can get guy leads of 41.28' (69% of 60', 67% of 61.5'). Do you think guy
leads at 67%-69% instead of 80% would be safe? Thanks for any help on this.
I appreciate it.
Jon N7XW
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