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Author Topic: Adding Section To Universal Tower  (Read 1245 times)
W3DDF
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Posts: 77




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« on: January 10, 2013, 07:20:54 PM »

I am interested in adding an additional tower section to the bottom of a Universal tower. In order to add the new section the fold over base stubs will have to be removed and placed on the new section.  I was wondering if anyone has done this before and have any suggestions on removing the fold over base stubs. Thanks.
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WB2WIK
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« Reply #1 on: January 11, 2013, 09:24:35 AM »

Aren't they embedded in concrete?  I can't imagine how you could remove them.
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AD4U
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« Reply #2 on: January 11, 2013, 10:13:13 AM »

I have two Universal aluminum self supporting towers.  The 80 footer has a 30" triangle base.  The 70 footer has a 26" triangle base.  As I remember they make bottom sections in 30", 26" and maybe 22" triangle spacings with either "straight" or "tapered" ends.

Assuming you have the Universal tilt over (hinged base) yes you can add one or more sections at the bottom as long as the triangle dimensions of the new section(s) are the same as those of your base and the existing bottom section.

Doing so may (will) alter the windloading specs.  Call Universal.  I have found them to be very helpful in the past.

Dick  AD4U
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WB2WIK
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« Reply #3 on: January 11, 2013, 10:18:33 AM »

I have two Universal aluminum self supporting towers.  The 80 footer has a 30" triangle base.  The 70 footer has a 26" triangle base.  As I remember they make bottom sections in 30", 26" and maybe 22" triangle spacings with either "straight" or "tapered" ends.

Assuming you have the Universal tilt over (hinged base) yes you can add one or more sections at the bottom as long as the triangle dimensions of the new section(s) are the same as those of your base and the existing bottom section.

Doing so may (will) alter the windloading specs.  Call Universal.  I have found them to be very helpful in the past.

Dick  AD4U

Maybe I misinterpreted the question but he said "removing the base stubs," which are the long steel posts that set in the concrete to anchor the tower...?  Once they're in place, I can't imagine removing them.

If he just wants to add one straight sided base section, those stubs would never have to be removed; he'd just unbolt the existing base section and bolt the new one in place, to the folding brackets on the existing stubs.
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W3DDF
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Posts: 77




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« Reply #4 on: January 11, 2013, 10:48:45 AM »

Thanks for the replies.  What I was referring to was the steel tube that slides into the lower part of the bottom section. These were already in place when I purchased the tower from the factory just wasn't sure if they would be a tight fit and removing them would be difficult.  I haven't tried yet so I guess I will find out.

I called Universal Tower and they said that I could increase the height but the only way would be to add another section the same size as the bottom section. I asked about a revised wind load calculation but he didn't provide that information.  It is currently model 12-40 which is 12 sq ft and 80 mph. I would like to know what the new loading would be though.
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AD4U
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« Reply #5 on: January 11, 2013, 11:35:52 AM »

The 3 each approx 5 foot long steel base sections ARE embedded in concrete.  I have 4 and 5 yards respectively on my towers.

Each leg of the bottom aluminum tower section is inserted into an 8" long (?)  piece (stub) of round heavy wall steel tubing and secured by 2 each 1/2 inch class 8 bolts placed 90 degrees apart and separated about 3 inches vertically on each leg.  Each of the three steel "stubs" are then attached (bolted) to the concrete embeded base via 2 each 1/2 inch class 8 bolts.  

It is hard to put in writing, but the base embedded in the concrete consists of three separate pieces of 2X2 inch or maybe a 3X3 inch heavy wall square steel tubing, with two pieces of thick flat steel welded to opposite sides of the top of the square steel tubing and sticking up some 3-4 inches above the square tubing.  This kinda forms a "square shaped Y" or maybe the top half of the letter H.  There are two 1/2 inch holes drilled through the sides of the Y (one about 3 inches above the other) where two more 1/2 inch class 8 bolts are used to secure the bottom section of tower (via the 8" long steel stubs) to the base.

In order to tilt the tower over, you remove ONE of the two bolts from each of two opposite base "Y's".  Then you remove BOTH bolts from the third "Y".  The tower then tilts over on the two "Y"'s with one bolt each.  This is the "hinge".

To add an additional base section, you first have to remove the three 8" long steel stubs from the existing tower base.  This may require lots of PB Blaster etc.  Bolt the new tower section to the previous tower bottom section and then bolt the three 8" long steel stubs to the new tower base section.

Reassemble the tower.  Both of my Universal towers have a 50 ft power pole mounted behind them.  I have a winch near the bottom of each pole.  A steel cable goes from the winch to a pulley on top of the pole and then over to the tower.  Lowering and raising the towers to "play with antennas" is fairly simple.

Dick  AD4U
« Last Edit: January 11, 2013, 11:46:34 AM by AD4U » Logged
K9MRD
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Posts: 331




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« Reply #6 on: January 11, 2013, 12:20:35 PM »

Would it be possible to put a 'same size' section above the base section?
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W3DDF
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Posts: 77




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« Reply #7 on: January 11, 2013, 05:40:40 PM »

The existing bottom section is a 22" taper so the section above that is 18". When I asked Universal about using an 18" straight section they say no, it had to be a 22" straight which would go under the bottom section. I had no problem with that, just want the tower to be safe and stay up.
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