Tower mount with elevation and Az


#1

I’m new to Mimosa, I need to upgrade a short distance backhaul between (2) Rohn 25 towers terrain elevation could reach 10 to 15 degree in elevation. On B5-lite is there a genuine solution for tower mount? Have seen it comes with J-poles but have not seen it installed in a tower like Rohn 25 or big ones like Pirod. Any suggestion how is done?


#2

Other than the options you’ve already seen, I’ve not seen anything else, from anyone else to answer this kind of need.

Like you, I have a pair of Rohn 25 towers — I found the Microtik QuickMount worked in my case, however, you seem to need to be able to adjust your elevation a lot more than I did so I don’t think this would help you much.

You might find the MicroTik QuickMount Pro as a potential solution as it has articulation for azimuth and elevation.

Unfortunately the B5-Lite relies on the jpole mount for elevation, and unless you’re prepared to have a special mount on the Rohn to attach that, there’s little options that naturally fir the B5-Lite vs a B5.

To retain the jpole mount, you might look at the “ROHN 25G TOWER ANTENNA ROTOR POST R-RP25G”

It has the proper attaching points for the tower, and a “mast” for attaching the jpole mount for the B5-Lite.


#3

https://www.balticnetworks.com/mimosa-fleximount.html

I would use metal zip ties, strap, or whatever they are called, to attach the Flexi-Mount to the tower, then you are shiny. The nice thing is if you need more angle, just mount it upside down. Though Bryan1’s suggestions look pretty good as well.

A slight aside, I have been looking at ~30ft Rohn towers. How do you figure out your wind loading? Rohn has everything from a 25G (https://www.solidsignal.com/pview.asp?p=25SS030) to a 65 G (and probably higher). But I guess I have never been introduced to how to calculate wind loading properly or even reasonable guesstimates. Or am I looking entirely in the wrong direction?


#4

I think Mimosa need to redesign this item to fit in towers and look the correct application mount. Also make this B5 Lite compatible with 24Vdc. I have solar sites already configured to operate using 24Vdc. So right know the set that comes to my mind is to use:

AF5X Radio
Air Fiber AF-5G23-S45
RF Armor Enclosure

With backhaul radios you cant go cheap :wink:


#5

There’s a lot that can go into it if you’re a purist — like PhD levels of a lot!

I’ll say up front, I’m no expert in this, but I’ve been doing installs of various types for a long long time…

That said, looking at it from a Mimosa radio usage.
We need to get the known wind-load numbers for each of their radios. I’ve not looked, or if I did, the number didn’t get my attention. But, it is important to know what that number is when considering towers of any height.

In the case of the B5C, or it’s PTMP sibling technically you should get numbers for this part of the system as well, and then add to that the separate antenna in question. 3rd party antennas almost always have wind loading information in their specs.

30’ with a couple of B5’s on it, as long as you’ve installed the base properly is designed to be self-supporting, and probably would be just fine from ground level. In fact, I have one installed on 40’ Rohn 25G, but it’s mate, also the same size is in a high-wind area, so we added guy wiring to the 30’ mark. Gusts exceeding 50mph are common there — just imagine the fun we had finding a low-wind time to install things!

Put it on a roof top, and it should be guyed at least at the top of each segment

If it’s partly supported by the side of a building, then other than a high-wind area, 40’ probably wouldn’t pose a problem, but I would strongly consider guying mid-way past support building.

The key for me is I don’t want the antenna to move at all if possible. If the structure it’s on is the least bit giving that could turn into torsional movement and then you risk the antenna moving physically off your required position.

The other catch is that the face of the B5’s and the B5-lite are essentially flat, and in fact concaved — not rounded which would help shed some of the wind loading. This means that they’re like a small wall up on a tower, and a gust will hit it pretty hard in some cases, and it won’t defect any of that.

This is a site that may shed some help to what you’re looking for.

There are better ones than this, but they’re closed in that you need to be a vendor or customer to get to them.

You may want to check out this link also…

http://www.steeltools.org/search?executeSearch=true&SearchTerm=ASCE+7-10+Wind+Load+Calculator&l=1

The last one is pretty in depth.

Antenna’s on towers is not something to take lightly. Having them fall can cause a lot of damage beyond the tower and what was on them, and can kill people.

Don’t forget to consider that climbing towers has it’s own hazards… there’s safety gear that should be used… Remember, it’s not the fall that kills you, it’s the sudden stop!


#6

I am TOTALLY with you on seeing the radios become compatible with solar-powered installations.

While there are power sources that can utilize solar and battery resources and convert to 802.3at or 802.3af, they’re another failure point, and honestly with solar power setups the consideration is to get a close to that raw power as possible to mitigate power losses.

Mimosa is showing off a lot more solar-based installations that customers have done, so it is possible, but the adaptations needed complicate it.

And, as you noted… there are other radio vendors who have setups that run on 12/24 vDC, so it is possible.


#7

@Bryan1 Thanks!

I am pretty sure I have seen wind loading info for the A5, the A5c on the other hand would be entirely up to the antenna manufacture for that info I would assume. I will look into the DX site and do some figuring, what I am looking for is a rural version of a micro-pop. Unfortunately for us we probably will be using Ubiquiti AF24 for the back-hauls and those are big and flat, we might just go with a light pole design instead, for ease of permits and minimize complaints about ugly factor.

Ya, we do the same but with frost and snow, boss won’t let us on top of peoples houses unless it is completely frost/snow free. Even harder to get up towers, but I will take a boss like her any day over the other kind.

We are already climbing towers, we just don’t own any of them (yet). Your advice is very pertinent though, we do climbing training 2-4 times a year just so that everything stays fresh and we keep on the safe side of things. Too many guys die climbing towers each year because they ignore basic safety.

Has anyone tried the DC Netonix switches in a solar system? We have them in our towers and they have a ton of power management features that seem like they would be oriented towards solar guys, plus they do not draw all that much power themselves.

On the other hand, a TP-DCDC-4848GD-HP (36-72V + Ethernet in --> 48 POE out) would be about as raw as you can get. Of course you have to have some system for killing the power when the batteries get low, but that comes with your battery management. Otherwise the DC to DC conversion needs to happen in the antenna which is probably not good for heat reasons.


#8

For some of my solar installations (non Mimosa) we just use the functions of the battery charger/controller.

It has functions to monitor not only input, but battery levels and will disconnect the load when the voltage there is too low, and will then turn it back on when it’s moved above the turn-on voltage. Works very nicely.

I noted your “Netonix” switches… VERY nice… those are just what I’ve been looking for in the past.

I have a new install coming that will be 100% “off-grid” that could benefit from that device… I always knew someone out there had to make something, but it’s so hit or miss when you have to start working way outside the box you just never know.


#9

Glad you like the Netonix, my only complaint about them is a lack of SPF+, but that is supposed to change soon. We have been installing them into our towers and the monitoring and cleaner cabling is making my life so much better.

I totally get you on the having to build from scratch and having no idea where to start. The step from “knowing what you are doing” to “I don’t even know what that is supposed to do” is the worst. Good luck, enjoy the journey.


#10

I would love to know what controller, switch you use and the wire routing to get the af-x to work.
Thanks
Craig


#11

@Craig2, not to be obnoxious about Netonix, but they have been verified to work and have a lot of features that are nice for solar installations. One or two of the Ubiquiti POE Switches I know is compatible as well (I seem to recall that there was one that had issues, but I certainly could be wrong on that point)

As a side note, we have entirely converted over to Netonix for our systems and are going to 48V only for our Towers/general sites. Seems that most manufacturers are going to 48V compatibility anyways…


#12

Hi William, Netonix is all I use also but on a solar site Im using the nano switch and then the airprism for AP and the power beam for the back haul and would love to use the AF-X. This is what I was wanting to know how others are doing the solar setups.