In a message dated 8/26/2011 12:23:09 P.M. Eastern Daylight Time,
k8ri-on-towertalk@tm.net writes:
On 8/26/2011 11:29 AM, HansLG@aol.com wrote:
>
> The idea is that I can inspect the ground connection. I also didn't want
to
> have things interfere with my lawn mower. I kept the wires as close to
the
> rod as possible, thereby minimizing the inductance. Right? Time will
tell.
>
> I have a good amount of old fencing laying around and decided to add
some
> "heavy fill" when I refilled the hole. It is more there to stabilize the
> ground. You may note that the only concrete is the three "pillars"
around the
> anchor irons. There is no access for a cement truck and this was my
method
> to make a base. Most on the momentum is taken up by the ~4' x 6' granite
> slab on the bottom of the hole.
How tall is the tower? As it's a guyed tower the base serves little
purposed than to keep the tower from sinking or sliding sideways. So the
amount of concrete and steel in the base is not critical.
The tower is 85 feet tall. The guy wires are at the 70 feet level. I did
studies before I decided what to do. I received the best torque distribution
by having the guy point at 70 feet. The stiffness of the base relieve some
of the torque on the tower sections. The tower was originally a self
supporting tower, but it can only withstand 80 mph wind. By adding the guy
wires
it will be able to ride out a 120 mph wind (which I liked a lot better).
This is with 20 sqf of antenna surface at the top.
>
> I used the "falling derrick" to raise the tower. You can see the derrick
> laying on the tower in one of the pictures. One guy wire was attached to
the
> derrick. I added some extra wire to the guy and used a couple of
> "come-alongs" to pull the tower up. A motorized winch would have made
it faster but I
> had the time. The "come-alongs" were attached the wire with "dead-ends"
> the same type as I used to fastened the guys to the anchors.
>
Why did you use 4 point guying and at what levels did you guy the
tower. If the tower is much over 60 feet the mass and type of guy
anchors becomes much more important than the tower base.
Again, I made calculations and liked the force distribution with four
wires. It makes the adjustment easier too, especially as I am not an expert
here. As the guy wires work opposite each other you adjust two wires at a time
without any influence of the others. Yes, I know it's not a big deal to
adjust three wires, but ... The surrounding terrain kind of "promoted" four
wires.
>
> Would have been nice to see pics of the structure that routed the
pulling
> wire in a high angle to erect the tower.
I will add some drawings/pictures later so you can study me contraptions.
73 de Hans - N2JFS
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