900 MHz 450i unboxing thoughts

No stainless steel hardware to seize.  However the brackets are lighter gauge steel than other Cambium sectors, and not hot dip galvanized.  Does anybody know what is under the silver paint?  I'm assuming zinc or cadmium plating?  I'd rather they not paint them, and I sure hope there is some decent plating underneath, or we're going to have rust problems.
No metric hex key needed, but you will need 10, 12 and 13 mm wrenches.  I liked it better when everything was 13 mm, although the hex key was a problem if someone had to replace a radio up on the tower.
The bracket design makes it difficult to get a crescent wrench on some of the nuts, the tower guy will probably need a 12 mm socket and a 13 mm box end.  Lots of tower guys only carry a crescent wrench, channellocks, pocket knife, and electrical tape, so they're going to reach for the channellocks.
The brackets are a bit flimsy IMHO, in particular I think the M8 bolts in the middle of the long slot in the upper bracket are a weak point.  The bolt head isn't wide enough, and that slot (which is already too wide) could open up given how long it is.
The rectangular bracket configuration with no diagonal brace, relying on tightening the screws really tight, is not a good design but many sector antennas have the same problem.
I wish they included two bottom brackets, I would substitute it for the adjustable top bracket for a little more rigidity.  Not sure why we need downtilt on a sector with 23 degrees vertical beamwidth anyway, unless the tower is on a mountain and we are pointing down at the valley, which would be pretty cool.  The adjustable bracket has tick marks but no degree markings.
The AP comes with an LPU style PG16 metal gland except it has a rubber insert, which is good if you don't intend on using their LPU and the Superior Essex BBDGE cable.  The rubber insert is already slit, so you can get an RJ45 terminated cable through it.  I guess if you get an LPU kit, it comes with the grounding glands already on a premade cable.
The AP just has a plug over the timing port, it doesn't come with a second gland.  So you might need to procure additional glands.
You might be able to force a 16 inch Cambium coax jumper to reach (if you don't care about bend radius), but I really think it needs more like a 24 inch jumper.
They give you 2 ground screws, which are still underneath when assembled but at least they are hex bolts.  But both of them seized hopelessly when I tried to loosen them.  This is not good!  The bolts are stainless steel, but I assume the tapped holes they go into are something like aluminum.  Not sure how I am going to ground this AP.
Next step is to see if I can set the timing parameters to coordinate with 900 FSK, there are other WISPs in the area using it, and I can't assume they will upgrade to 450i.
I do notice the SM has a place on the back to mount it to a J-pipe or pole with a hose clamp, this doesn't seem to show up in any of the photos on the website or in the literature.

I forgot to mention, they went to the Ubiquiti style floppy carriage bolts.  I ran some nuts down to hold them in place like other 450 sectors, but had to use a couple oversize washers because of the square part of the carriage bolt sticking through.

In the future, I will probably swap out the carriage bolts for regular fully threaded hex bolts.  Maybe just use 5/16 galvanized from the hardware store.

Also, the square holes for the carriage bolts seem oversize, kind of a sloppy fit.


Thanks for the thoughts Ken.  We appreciate you taking the time to do this.

A lot of the choices we made on the 900 MHz product were in order to keep the prices reasonable (especially on the SM side of things).  If you believe that Cambium went too far in this direction, please let us know.  We absolutely don't want to sacrifice quality and reliability to save a few pennies...

Also, we've already made some modifications to the braketry on both the AP and SM to enable easier installation and include features more like the other antennas in the portfolio.  Look for them on the antennas starting in the February timeframe.

@Ken Hohhof wrote:
Next step is to see if I can set the timing parameters to coordinate with 900 FSK, there are other WISPs in the area using it, and I can't assume they will upgrade to 450i.

Hi Ken -

You will want to know what SW version and sync timing sources the other WISPs are runnning, if at all posible, because you will need to run some legacy timing settings on the AP (covered in the release notes) until all FSK sectors have been upgraded to 13.4.1 to have their timing alinged properly too.  This may be difficult depending on who you are working with, but there are only a few options.  So you could also revert to trial and error.  

But it will benefit you as well as them to know the right setting at the start so that you don't impact each other.  For more details, see the release notes and the GUI.  The GUI has a helper table to tell you what selection to make based on SW versions as well as sync sources.  You'll find it at the bottom of the Radio configuration page.



I figured you got rid of the stainless steel hardware because of people complaining about it seizing.  As long as the brackets don't rust, I'm not too worried.  It might be interesting to ask some other customers if they like the long bolts on the clamp halves the old way or the new way better, I doubt there's much cost difference.

I was wrong about the coax jumpers, you can make the 16" jumpers fit, it's tight though if you want to slide the AP out of its slots after you've weatherproofed the N connectors.

Note that I couldn't find anything to complain about with the cross pol yagi or the way the SM attaches to it.  I was prepared for it to be kind of cheap and flimsy, but it's actually quite well built and very easy for the installer to assemble.  I mean, it's still a cross pol yagi, and I'd like a panel option, but no complaints about the build quality.


Most of the hardware has what's called a dacromet finish (what looks like the silver paint).  This is a corrosion resistant finish that passed all of our accelerated life salt fog testing parameters.  It should not rust.

We haven't received our pre-order so I have no experience yet. But I will say this. The stainless on stainless seizing is an issue with both the 450 and ePMP. And I will agree with Ken, the ability to install the bolts with nuts to keep them taught greatly helps during install, especially at times when we have only one guy on the tower.

Hey Ken, I'm with you on a lot of this.  The hardware design choice on these antennas is pretty poor.  Far too "floppy".  We find that the hardware on the 3.65 sector antennas is great - nice and solid, a single wrench to work with.  But we also hate  the stainless hardware.  Hot dipped galvanized hardware would be nice.  I would rather pay an extra $100+ for better hardware than deal with installation troubles when it's -20°C out (we installed 2 of these at 350' yesterday).  That said, a crescent wrench up a tower?  Maybe just for a hammer.  haha

The SM's are nice.  The antenna seems light duty, but it doesn't need to be any heavier for where they get used.  I like the silicone boots on the flyleads, and the quick release plate.  Well done.

    I spent a couple hours yesterday "arguing" with one of these sectors. The biggest complaint I have is the fact that there are 3 different sizes of bolts. Ubiquiti and others have started to standardize around 13mm. I must admit I simply assumed that was  the case here. We don't even keep a 1/2" wrench in the toolbags anymore to prevent confusion.  That'll  teach me to not read the documentation before a deployment....

   Also If there was somewhere to put a carabiner or lanyard that wasn't part of the mounting bracket it would make huge difference. I would place a bent plate  just inside the top mounting bracket to help keep the lift point  near the center of gravity. 


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Thanks for the feedback... we are looking at making some changes moving forward to enhance the ease of deployment and usability of the product.

I would recommend replacing the 12mm bolts with 13mm. One less wrench size at the least. The 10mm are fine and are standard kit for most applications these. I’m glad to know now that it’s all metric. 7/16", 1/2", 11/16" are all common but very annoying to pick through at 30m up. Having a whole set of wrenches in your harness tool bag is difficult. Especially if you are at the bottom side of the operation. (if you can dodge a wrench… you can build a network)