Rick, I had 70 feet of Rohn 25 hinged at the bottom to fold over. I built
my own hinge plate that would hinge the world(maybe). The pole I used for
the hinge cable was a BIG Oak tree about 40 feet away from the tower. I
only had a 4 element 10m antenna on top. The pulley was up in the tree
about 40 to 45 feet. I had a 3/8ths cable rapped all the way around the
tower in 2 places, #1 was at about 40 feet and #2 was at about 52 feet. I
then ran a cable from a point that would pull on #1 and #2 points on the
tower as equal as possible. I did this while the tower was laying on the
ground. After the cable went over the pulley in the tree it went straight
down to a 8000 lb winch I had mounted to the front of my Suburban with a
454 CI engine. When it was going up I thought it was going to lift the
front wheels off the ground!!! The tower had a hell of a bow in it and we
had to tie tag lines on it to keep it from moving side to side. I worked
in a structural steel shop for 14 years and let me tell you it was
SCARY!!! And I had no weight on the top like what you want to put on it.
Get your buddies and put it up like it is supposed to be put up!!!!
TRUST ME...
73, Bill KB3AUG
Riverton, WV
On Sun, 15 Mar 1998 19:37:01 GMT "Rick Bullon" <kc5ajx@hotmail.com>
writes:
> Hello All
> I am finally geting ready to put in the base for my first tower
>project. I have 40 ft of Rohn 25 and plan to add another 30ft to it to
>
>make 70ft total height. I want to be able to fold this tower over it
>came with a BPH25G base plate and a 19ft pole to surport the tower.
> I feel that the 3/8 bolts on the base plate are to small to fold
>this
>over safely, would the SBH25G be a better choice? or should I build a
>stronger base plate my self? I contacted Rohn with this question and
>the
>response I got was "We just build them we don't energineer them"
>inother
>words they won't say.
> My next question is about the support pole to hold the tower when I
>fold it over. THe pole I got with the tower is 19 ft long and about 1
>1/2" in diameter. I plan to put 2 section of pipe under this the
>bottom
>section will be 3 1/2" in diameter and 5 ft in concrete the middle
>setion will be 2 7/8" diameter. I plan to overlap them about 6" to a
>foot so the total pole will be 5 ft in concrete and 35ft above ground
>will this be big enough pipe and be long enough to fold over the 70 ft
>
>tower with a TH6 on top or do I need to go higher or bigger with the
>pipe? It will only have a load on it when I have to fold the tower
>over.
> I've been told by a local ham that this "should work" but it would
>be
>best to guy the pole when I fold the tower over, so I plan to have 5
>guy
>post to guy too, 3 for the tower and 2 for the pole.
>It should look like this
>
>
>
> o o
>
>
>
> o 0<|
>
>
> o o
>
> Well I'm no artist on the key board but in the above diagram the
>top
>and bottom post on the left side are for the pole when I have to fold
>over the tower over the rest are for the tower it is not drawn to
>scale
>but I will use the recommended 80% of the tower heigth. I beleive it
>will be 56ft out from the tower. I plan to guy this thing at 20 40 and
>
>60 ft ie every other section right or wrong? Can I use the drycron
>rope
>for guys? I hate to try and figure out where to break up the wire guys
>
>with insulaters and the Kelvar seems expensive but I could probably
>save
>up enough to get the Kelvar stuff I think the brand name is
>Phillystran
>isn't it?
> THe base wil be 4X4X5 ft deep is that big enough?
> Right now I have the 40ft of Rhonn 25 tower (will add 30ft more) the
>TH6 beam and a Tailtwister rotor. future plans might include an A3WS
>for
>the WARC bands not sure if I will try to put a forty meter beam on it
>probably will be too much antenna on one tower.
> AS you csn see I have been planing this for a LONG time, several
>years
>in factand I still have lots of questions. I need suggestions from the
>
>wisdom of the group as I don't plan having to redo this project. I
>want
>to do it right the first time.
> And for Steve ( sorry I can remeber your call if you want to figure
>the wind for this area I'm in Parker county Texas).
>73 and Thanks
>Rick
>KC5AJX
>
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>
>
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>
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