Well --- that all depends on a lot of things. Like wind district, guy
spacing, tower loadings (antenna's and where on tower), ice loading, soil
conditions, and a few others that I have not thought of lately. So it is
real hard to give an estimate over the the net.
I will relate one installation that I designed for a friend using EIA-222
Rev E.
Wind district is 80 MPH (Iowa), Tower is 70' of Rohn 25G guyed at 32 and 65
feet. 1/4" EHS guy wire. Guy anchors are out 50' and up 6'. Tower has 10'
of mast with TH6 at the top of the tower, and 2 meter and 440 yagi's
above. A couple of inverted V's off the tower.
Guy anchors are 8" I beam going down into a 7' deep 20" diameter hole. I
looked at pipe and it wouldn't work in the sizes I could find locally
(cheap).
This one is marginal with standard ice load so we are still arguing about
it. I did talk to the state climatologist and got some more realistic ice
load info, so I am at least satified that it won't wind up in his living
room next March.
BTW EIA-222 Rev F is current and it calcs out to a deeper hole.
On the other side is one that I did not engineer. 100' of Rohn 25G with an
8 element tri-band something up there, 6 on 6 meters and 2 meter and 440 on
a 10' mast. Three sets of sloping dipoles on 40 and 80 (switchable for
driven vs reflector, but that is an other story). Tower is guyed at 3
levels with 3/16" EHS, anchors are out about 80 feet. Anchors are 6"
schedule 40 pipe 6' out of the ground. At least one of the anchors has bent
and pulled in about 8". Tower has been up about 5 years. I have argued with
them to get the anchor situation straightened out, and offered to help for
free, but not change in sight. Fortunately this one is about 150' away from
the house, but it would still be a mess to clean up if it came down.
So there are two real world data points. I would suggest that you get some
local expertise. I personally like elevated guy anchors. They keep me from
killing myself on the guys. They do however cost about 4 to 5 times as much
as buried. They are harder to work on once up. And they need to be
carefully engineered.
73 de n0yvy steve
ARRL Volunteer Consulting Engineer.
Disclaimer: My company and I agree on at least one thing: My opinions are
my own.
______________________________ Reply Separator _________________________________
Subject: Guy supports
Author: Michael Causey <kk5ep@netdoor.com> at ccmgw1
To: <towertalk@contesting.com>
Date: 10/15/96 2:49 AM
Hello gentlemen:
I would like to put up elevated guy-wire supports, approx 5-6 feet above
ground. What type pipe material should I use and how wide and deep should I
make the holes? The tower will be 100 ft of r 25g. Thanks, Mike.
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