Base Push Up Tower Questions

[edfiero1]

I'd like to put up a 3 or 4 element beam. Obviously a tower is the way to go, but I can't really afford that. So I am wondering about the feasibility of using a push up mast like the Rohn H50.

I would like to avoid the use of guy wires. If I discard the top section of the mast, and then have a couple of stand off mounts to the side of the house, like at 15 ft and then at the peak of the roof about 25 feet up, would that give sufficient support that I could get by without the guy wires?

Also, any problem with putting a rotor at the top of the pole (since I am discarding the top section, this should give a little more 'meat' at the top)? Suggestions on mounting the rotor would be appreciated.

Thanks

 

[undertaker]

If you put up a beam you are going to need guy wires.......

 

[BJ radionut]

Don't discard the top section slid it down inside for extra strength...use all the other sections slide down inside as much as possible to get just past the top support at 25 ft.
Leave just enough of the biggest section at top of well mounted (Bracket/LAG screws etc...) near the 25ft support to mount rotor. Then add only enough tubing out of the top of the rotor to mount beam (1-2ft) and hope for the best...Anything more and Guys are the only answer to support rotor and suggest 3 element beam(Horizontal only)...Maybe a Moxon (2 element) would be something to think about...otherwise your asking for a issue ! IF beam was to be Vertical...Suggest not!
Make sure the bottom of the pole is secure(say drive a H/D pipe 2-3 ft down) and slide bottom of pole over that...The mount at 10-15ft should also be very secure to building(NO FLEX) in pole...
GL
All the Best
Gary

 

[Captain Kilowatt]

Don't discard the top section slid it down inside for extra strength...use all the other sections slide down inside as much as possible to get just past the top support at 25 ft.
Leave just enough of the biggest section at top of well mounted (Bracket/LAG screws etc...) near the 25ft support to mount rotor. Then add only enough tubing out of the top of the rotor to mount beam (1-2ft) and hope for the best...Anything more and Guys are the only answer to support rotor and suggest 3 element beam(Horizontal only)...Maybe a Moxon (2 element) would be something to think about...otherwise your asking for a issue ! IF beam was to be Vertical...Suggest not!
Make sure the bottom of the pole is secure(say drive a H/D pipe 2-3 ft down) and slide bottom of pole over that...The mount at 10-15ft should also be very secure to building(NO FLEX) in pole...
GL
All the Best
Gary

I agree with all of the above. This is the ONLY way I would do as you desire with what you propose.

 

[Shadetree Mechanic]

I would not use a push up pole. To me push up poles are temporary. I would use two inch iron pipe. Dig a one foot hole to put it in. Lag a pressure treated 4x4 to the house long enough to hit at least two studs in the wall. You should be able to find a fence post bracket to bolt the pipe to the 4x4. Put a reducer at the top for a short section of one inch pipe to put the rotor on. If you only want to do this once then that is what I would do.

 

[nomadradio]

As the old saying goes, "Torque is cheap".

Any time the boom is positioned at an angle to the wind direction you will get a twisting force on the pole. This is why you should never use "ladder type" tower sections for a beam antenna, only for verticals or small TV antennas.

The diagonal braces on "Z-bar" tower strengthen it against that twisting motion. The horizontal braces on the "ladder-type" tower do not. Extra guy wires may help, but not enough.

The longer the boom, the more torque the wind can put onto the antennal mast and support. A push-up pole is not reinforced in any way to resist twisting forces. A decent breeze will turn it into a pretzel if you put a beam antenna on it, most likely.

73