# DIY Antenna Tower to go OTA



## bobp (Mar 4, 2014)

I've done some research in going over the air, OTA.
I'm building a tilt over tower.

I've drilled 2-31/2' deep 12" wide holes, then dug them out another 6" or so, stood 2 10' long sections of 4"RMC 4.5 OD, .225 wall thickness Galvanized pipes, I then drove them with my hydraulic driver on my tractor.
I made it to about 4' out of the ground. Ones 4" further than the other, as I hit solid rock.
They're roughly 36" apart.
I'm going to use my hand post hole.diggers to clean out around both pipes and then I'll dig out a 6" deep recessed rectangle 12" around both.
I also am thinking I'll put a bag down inside each pipe to add dead bottom ballast.
I'll mix up quick Crete in my tractor bucket and have 6" all the way around both 4' deep, and then the rectangle...
I'll cut bracing and weld in between both, then drill a hinge hole 3/4" in both and in the first up right, a 31/2" drill stem pipe, 35' long, then I'll reduce down from there with a minimum goal of being 50' but 60-80' would be much better.

Have you ever done something like this? What do you see wrong with it?


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## bobp (Mar 4, 2014)

There will be something around 1500# reaching 6' in the ground....15 80# bags and then the pipes weigh in at just over 100# each...


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## AmericanStand (Jul 29, 2014)

Never anything like that
To me it seems like your hinge over point is way too low. 
I want my hinge over point to be high enough to balance the rest of the antenna. 
Around here utility companies rule of the thumb is 10% of the height in depth +2 feet
On an 80 foot antenna that would be 8 feet +2 feet for 10 foot of total depth buried
If you are getting 35 foot drill stem I’d be inclined to have 5 feet of that in the ground and the hinge over point at the top of them
That way 30 feet of thicker bottom pipe which stand a better chance of balancing the additional 50 feet of lighter pipe above it. And of course you could fill the interior of the pipe with lead shot or cement to achieve perfect balance.


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## AmericanStand (Jul 29, 2014)

I’d also be inclined to weld a x-brace to the inground portion where it would be about 2 feet underground


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## Savrens (Jun 23, 2007)

Check this out. 
*Windmill Raising*


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## bobp (Mar 4, 2014)

I could take two of the drill stem pipes and run them down inside the 4" ridged. Then make my thing point at 25- 30' up....that would be an easy modification. I have several sticks of it.
Of course the first rise would be the drill stem too.
Then run up the 2" rmc and EMT from there. Using lighter pipe as I go up, step down fashion 
This would definitely make the whole thing bottom heavy.


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## bobp (Mar 4, 2014)

The utility company poles here have 6' in ground for 30&35' wood poles.....8' for 55&60s.
Above 60 they go with cement piers. But the wind load and pure gravitational force on the line is huge...

2- 4' deep holes 12"+ around with a pad around top oughta equal 8'....and I can guy it if absolutely necessary


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## AmericanStand (Jul 29, 2014)

You’re gonna put an antenna at the top of this that’s a Lotta wind force too.

2 Holes 4 feet deep is nothing at all like what you’re going to need.
I’d be thinking more like one hole 10 foot deep with a couple of feet of concrete at the bottom and then that X brace 2 feet in the ground
Specially with just two pipes 4 inches In diameter that’s very little ground contact and very little pivot point versus leverage.
4 foot deep holes will tend to pivot around a point about 3 feet down that means you’re gonna have 80 feet of leverage against 1 foot of pipe.
Think of that 80 to 1 leverage!
I don’t know what type of antenna you have in mind but would you like to hold it outside in a 60 mile an hour breeze? How about 80 times that?

Going deeper is really cheap. I would certainly be inclined to do that. And honestly Id be thinking g to set up some sort of a guy wire system ,80 feet is high.
Even 60 feet is quite a bit.


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## Bearfootfarm (Jul 13, 2006)

bobp said:


> What do you see wrong with it?


Not enough support for that much length. You need something more like the Eiffel Tower, with a wider base and a gradual taper to the top.


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## bobp (Mar 4, 2014)

Re thought, and looked at other designs, which are similar, but this is my current design. 
Base
2 yds quickrete 
2 41/2" pips driven to rock 6' under ground 4' above ground 
Riser legs 30', 
Tilt riser stage 1 35', hinged above center, heavy to the bottom, so it will want to stand so to speak. 
2nd stage rise 2" galvanized emt pipe
3rd stage 10' 1" emt
Antenna approximately 6 sqft wind load.


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## bobp (Mar 4, 2014)

Interesting link

https://freeantennas.com/tilt-over-tower/index.html


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## AmericanStand (Jul 29, 2014)

Wonder if you could use one of these somehow ?

https://www.homesteadingtoday.com/t...ass-blades-at-dump.603524/page-2#post-8554122


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## bobp (Mar 4, 2014)

Hmmm...


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## AmericanStand (Jul 29, 2014)

Wonder if you could cut it down to 80 feet and bolt climbing rungs to it ?


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## Bearfootfarm (Jul 13, 2006)

You'd need to cut it to about 50 feet just to be able to transport it, and it would require a huge amount of concrete as a base to resist the wind forces. 

Antenna towers are made the way they are to allow the least amount of wind resistance, and these blades are the opposite. 

They aren't designed to be mounted to anything except at one end.


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## Bearfootfarm (Jul 13, 2006)

Here's the best use for them so far:


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## AmericanStand (Jul 29, 2014)

Bearfootfarm said:


> You'd need to cut it to about 50 feet just to be able to transport it,.


 Nope obviously they are transported to the site. 
If you can get them down to 75 feet you might not need a permit at all. 
The portion closest to the hub would be the strongest. 
mounting them vertically would also take advantage of their strongest position.


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## bobp (Mar 4, 2014)

You'd be surprised how many municipal street lights are similarly constructed fiberglass poles, designed to be directly buried......I'm sure a person could make some sort of alternative use project for them...


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## AmericanStand (Jul 29, 2014)

I want one
Wonder how to get one


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## AmericanStand (Jul 29, 2014)

Now that I think about it there is a rest area with one on display. It’s in Kansas I think


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## Bearfootfarm (Jul 13, 2006)

bobp said:


> You'd be surprised how many municipal street lights are similarly constructed fiberglass poles, designed to be directly buried.....


Those are shaped to be wind resistant in all directions and are a much smaller diameter. They are also only about 40-50 feet long.


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## AmericanStand (Jul 29, 2014)

Other that shorter how is that any different than any wind mill blade ?


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## Bearfootfarm (Jul 13, 2006)

AmericanStand said:


> Other that shorter how is that any different than any wind mill blade ?


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## AmericanStand (Jul 29, 2014)

Cat got your tongue or are you just unwilling to admit when you’re leading others astray?


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## AmericanStand (Jul 29, 2014)

https://images.app.goo.gl/froifdXNz73zrYjT8
Looks like it will work


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## muleskinner2 (Oct 7, 2007)

With that size pipe you should be good to thirty feet with guy wires at twenty five feet. Any higher and you will need to go to bigger pipe. And guy wire every twenty five feet. I don't remember the formula to determine how far out to put the guy wire anchors. The tallest tower I ever put up was six hundred feet. The pier at the base was six feet square and twelve feet in the ground. The guy wire anchors were four feet square and twelve feet deep, with a two inch eye bolt with a anchor on the bottom set inside the concrete. There were three anchor bases for each leg of the tower.
At thirty feet tall you can install or service the antenna with a ladder. Any taller will require step pegs. I would not recommend a tip over tower.


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## Bearfootfarm (Jul 13, 2006)

AmericanStand said:


> Looks like it will work


Those are being used as "art"
They are mounted on huge concrete bases.

They aren't supporting anything and they don't appear to be anywhere near as large as the ones being discussed in the OP

They would have to be set in place with a crane.

https://www.npr.org/2019/09/10/759376113/unfurling-the-waste-problem-caused-by-wind-energy


> Decommissioned blades are also notoriously difficult and expensive to transport. They can be anywhere from 100 to 300 feet long and need to be cut up onsite before getting trucked away on specialized equipment — which costs money — to the landfill.


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## AmericanStand (Jul 29, 2014)

Lol size really doesn’t make any difference no matter what size they are they are designed to handle Highwinds while stopped with ice loads and in any position

Since the OP was wanting an antenna of about 80 foot in height removing 40 to 100 feet of the antenna would leave him with the lower portion which would now be well within its design limits even if he added an antenna to it. 
Perhaps there’s an engineer here that might know the structural Loads they are designed for ?
Cutting one down to 70 or 80 feet would make them fairly easily transportable no special equipment required at that point


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## AmericanStand (Jul 29, 2014)

For a 1.5-MW *turbine*, typical *blades should* measure 110 ft to 124 ft (34m to 38m) in length, weigh 11,500 lb/5,216 kg and *cost* roughly $100,000 to $125,000 each. 








https://www.compositesworld.com › ...
*Wind turbine blades: Big and getting bigger : CompositesWorld*


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## Bearfootfarm (Jul 13, 2006)

AmericanStand said:


> Lol size really doesn’t make any difference





AmericanStand said:


> no special equipment required


It makes all the difference.
https://www.npr.org/2019/09/10/759376113/unfurling-the-waste-problem-caused-by-wind-energy


> Decommissioned blades are also notoriously difficult and expensive to transport. They can be anywhere from 100 to 300 feet long and *need to be cut up onsite* before getting trucked away *on specialized equipment *— which costs money — to the landfill.


I won't run around the circle again.


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## AmericanStand (Jul 29, 2014)

Bearfootfarm said:


> It makes all the difference.
> https://www.npr.org/2019/09/10/759376113/unfurling-the-waste-problem-caused-by-wind-energy
> 
> 
> I won't run around the circle again.


 I’m sure you will since it’s the circle of your own making.

You quote me out of context and then try to say something that was never said. 
My “size doesn’t matter was in relation to their design parameters
No Matter what size they are They are designed to handle heavy loads of ice and wind in any position while stopped.

And the full quote where I said no special equipment required Applied to the cut down pieces

“Cutting one down to 70 or 80 feet would make them fairly easily transportable no special equipment required at that point”


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## bobp (Mar 4, 2014)

By the time a person paid the transportation, crane, and concrete invoice he could have put up a proper tower...turbin blades are not a viable option.


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## AmericanStand (Jul 29, 2014)

Sadly I’m afraid you are right.


But it would be so cool


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## bobp (Mar 4, 2014)

I'm not going as high as this guy. Hes 80' to the base. No Guying.
He use 4x6 tube, likley 11ga, for his base legs.... I'll look up side wall pressure specs on the two....

The Ham guys have done all sorts of big towers....

Custom Built 80-Foot Tall Free Standing Ham Radio Tip-Tower in Action! This is COOL!


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## AmericanStand (Jul 29, 2014)

How about one of these?
https://www.ironplanet.com/for-sale/Bucket-Trucks-1990-FWD-6618CC-T/A-Bucket-Truck-Virginia/3178421?h=5000,sm|0,k|Boom+truck,sort|p+asc,mf|1&rr=0.5&hitprm=&pnLink=yes
That will get you up to about 120 feet


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