Rohn 25 base dimensions

[emtunderwood]

Okay…. I know there are all over the forums about the Rohn 25 concrete base dimensions. But nothing for what my intended purpose. From everything I’ve read most say 3’x3’x3’ for the base then if there’s a tilt it’s even bigger. I’ve started digging by had the 3’x3’x3’ and about 65-70% done with the depth.

What I intend to use the Rohn 25 for is just a single Gen 3 residential starlink at the top and a small discone antenna a scanner. I plan on going 25ft and mounting the starlink directly to the top section and the discone about 5 ft below that on a small offset.

I don’t have room for guys unless they are short jacked about 6ft from the tower. I don’t think I have that much room. Now the soil is hard yellow clay with sandrock. Have had to spud bar the whole thing. I’m 2ft deep now and the rock and clay is getting harder. If I’m 2 ft in the ground and have 1 ft above is that enough? Or should I try to go 6 in deeper and drill rebar in the ground and torch the ends over 4in and just leave 6in form above ground and use the j-hooks to set the plate in the concrete on top.

What are your suggestions?

 

[AK9R]

There's information online about using Rohn 25G in a self-supporting application. Here's a link: https://www.3starinc.com/manuals/RO...0dly359V04ySVA87ECHIaXmOiGLo8yDLEZTKwm6vBilW4

The installation "rules" are different for guyed vs bracketed vs self-supporting.

 

[emtunderwood]

There's information online about using Rohn 25G in a self-supporting application. Here's a link: https://www.3starinc.com/manuals/RO...0dly359V04ySVA87ECHIaXmOiGLo8yDLEZTKwm6vBilW4

The installation "rules" are different for guyed vs bracketed vs self-supporting.

I understand what you've sent... However, I have just a plain 25g tower wanting to put a starlink dish on it. The 25GSS I do not have...

 

[buddrousa]

I do not care if it is 30 feet no house bracket no guy wires it still gets a 3x3x3 the information you were given is known by the users that know is known as the Rohn Bible. Do not forget NEC Nation Electrical Code Grounding your Local Government is also a good source. But do not go below minimum standards.

 

[K6GBW]

The 3x3x3 base is need to have enough weight so that in high winds the tower base won't rotate in the soil. I've done a 25 footer completely free standing, but it has to be lightly loaded. If you put only a starlink antenna and a small discone it should be fine. But with heavy antennas with lots of wind surface or any higher then they really should be guyed. Also don't forget the grounding. I'm curious though, why the need to put a starlink antenna so high? As long as they can see the sky they should work fine. Are you in a depressed area with trees or something?

 

[emtunderwood]

Clearing trees and a roof that I’m not drilling the side of a newly remodeled exterior.

 

[mmckenna]

These are all engineered designs. The 3x3x3 base is what the manufacturer requires for the tower to meet specifications.

If you do less than what the manufacturer requires, all the specs go out the window.
Will 3x3x2 work? You'd need to hire an engineer to determine that, not ask questions on a hobby radio webpage.

If there's zero chance the tower can fall over and hit a neighbors house, land on power lines, land on a human, then it's up to you to decide if you want to hire an engineer or not. If you short the base design and it falls over and hits your home, homeowners insurance is going to laugh and walk away without leaving you a big check for home repairs.