Offset / Sidemount brackets

[emtunderwood]

What offset / sidemount brackets to be used with the SD-224 offset configuration. I know sinclair has their mount. But there has to be other options and what distance should the antenna be spaced off the tower? I've looked and looked for different options, seen some different things in the wild but cannot locate the mounts. And I'd prefer and top sway brace. I know theres the mounts for the DB224 which is 20 inch and commscope has one with no sway brace. I just cannot find something that will get beyond the 1/4 wavelength to the 1/2 wavelength on a Rohn 45. Any suggestions?

Thank You

 

[wgbecks]

What offset / sidemount brackets to be used with the SD-224 offset configuration. I know sinclair has their mount. But there has to be other options and what distance should the antenna be spaced off the tower? I've looked and looked for different options, seen some different things in the wild but cannot locate the mounts. And I'd prefer and top sway brace. I know theres the mounts for the DB224 which is 20 inch and commscope has one with no sway brace. I just cannot find something that will get beyond the 1/4 wavelength to the 1/2 wavelength on a Rohn 45. Any suggestions?

Thank You

My go to side mounting hardware is the DB-5004 that is a very heavy-duty mounting that may be an overkill for your application.

The primary advantage of this arrangement is that you can easily adjust he distanced from the face of the tower to produce the best possible radiation pattern per system requirements. The added rigidity is superior electrically in preventing electrical discontinuities caused by
mechanical motion that can and does create desensitization in duplex systems.

The 10-foot pipe sections can be cut or shortened as may be necessary. I prefer the clamp across the face method to promote a ridged
mounting that eliminates twisting moments that you’d otherwise experience with single leg attachments.

DB-5004 Description

Adjustable Side Mounting Kit for 3 in (76.2 mm) OD round members. Use to mount all metal mast antennas away from side of tower
measuring 2 to 8 feet (0.61 to 2.44 m) across the face. Two 10-foot sections of pipe and six clamp assemblies are included.

 

[emtunderwood]

My go to side mounting hardware is the DB-5004 that is a very heavy-duty mounting that may be an overkill for your application.

The primary advantage of this arrangement is that you can easily adjust he distanced from the face of the tower to produce the best possible radiation pattern per system requirements. The added rigidity is superior electrically in preventing electrical discontinuities caused by
mechanical motion that can and does create desensitization in duplex systems.

The 10-foot pipe sections can be cut or shortened as may be necessary. I prefer the clamp across the face method to promote a ridged
mounting that eliminates twisting moments that you’d otherwise experience with single leg attachments.

DB-5004 Description

Adjustable Side Mounting Kit for 3 in (76.2 mm) OD round members. Use to mount all metal mast antennas away from side of tower
measuring 2 to 8 feet (0.61 to 2.44 m) across the face. Two 10-foot sections of pipe and six clamp assemblies are included.

Thank you for your response.. It's a Rohn 45 tower and the DB-5004 is 2 pipe offsets. Is that meaning 1 at the top and 1 at the bottom or 2 at the bottom and no top sway brace? 6ft off the tower which has a 16in face might be a lot of strain on a tower that is 30+yr old with the SD-224 antenna. I think that might be too much.. But I think what I'm trying to ask is with a Rohn 45 using the 1/4wave spacing 20in mount that would be used for a DB224 would that suffice or would the 1/2 wave spacing be better and what are the options, i.e. pros and cons to mounting this antenna and would 1/4 or 1/2 wave matter behind the elements toward the tower as the antenna will be offest centering up our coverage area not omni.

 

[wgbecks]

Thank you for your response.. It's a Rohn 45 tower and the DB-5004 is 2 pipe offsets. Is that meaning 1 at the top and 1 at the bottom or 2 at the bottom and no top sway brace? 6ft off the tower which has a 16in face might be a lot of strain on a tower that is 30+yr old with the SD-224 antenna. I think that might be too much.. But I think what I'm trying to ask is with a Rohn 45 using the 1/4wave spacing 20in mount that would be used for a DB224 would that suffice or would the 1/2 wave spacing be better and what are the options, i.e. pros and cons to mounting this antenna and would 1/4 or 1/2 wave matter behind the elements toward the tower as the antenna will be offest centering up our coverage area not omni.

The DB-5004 does not dictate how or where to make the attachments. I have always placed one at or near the base of the antenna, and the other near the top of the antenna mast.

I do not recommend placing the antenna 6th out. Practical spacing will fall somewhere between 90 and 180 electrical degrees off the face. Once you've determined optimum spacing for your use case, you may want to consider cutting off excess pipe length.

Keep in mind that side mounting distorts published pattern plots supplied by antenna manufacturers. To that end, I have relied on NEC modeling for well over twenty years to determine the optimum distance and orientation of the antenna about the tower in an effort to achieve the best possible coverage pattern for side mount applications.

Good luck with you project!

 

[wgbecks]

One last comment. Do space mounting hardware (pipes, clamps, etc.) as far from the antenna elements as possible to avoid detuning.