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Ubiquiti AMO-5G13 vs. Rocket Dish for new deployment

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Ubiquiti AMO-5G13 vs. Rocket Dish for new deployment

I'm just getting started with AREDN and there are very few nodes in my area. Another ham and I are planning to get started together and hope to encourage other hams in the area to get started as well.  He lives 3 miles SSE of me.  There is another node 7 miles further SSE of him that is connected to a node about 16 miles NNE of him.  From the map that user has both a 5ghz radio (NanoBridge 5) and a 2ghz radio (Bullet M2).  The 2ghz radio is the one connected NNE of him.  If I'm just getting started in our area, is an omni 5ghz antenna better or 5ghz directional high gain a better way to go?  I've also considered the Altelix 4-port dual-band omni with the Rocket M5 and M2 radios to make it easier for new users in the area to connect up to me.  Whichever radios are chosen would plug into a Mikrotik HAP ac lite which I would flash with the AREDN firmware and plug that into my home network.  What would be some pros and cons to the above equipment choices?  Like others, trying to balance equipment choice with cost effectiveness.

nc8q's picture
Just getting started...which way to go?
I recommend contacting the active node owners before purchasing any nodes.


Omni vs. Directional
Any guidance on choosing between omni vs. directional antennas?  Reason I ask is that there was a YouTube video of a guy who pretty much said omni is NOT the way to go.  When I hear "Mesh" I think SP to MP connections, e.g. Omni so I tend to disagree.  His argument was something to do with saturating a geographic area with RF.  Without a better understanding of how this all works, I need more info to make a decision.
What locations do you have available? Mountain top, high building, tower, houses? What are the size and shape of areas to be covered? Then we can make recommendations. Directionality and gain are your friends in Ghz. I will agree an omni is usually the least common choice.
No mountains or high buildings around us.  Mostly houses all around and agriculture. I'm in a single story home but have 2-story homes around me.  Can't really put up a tall mast due to HOA.
How far?
What distances are you trying to cover? If it's 'the neighborhood' I would at a minimum recommend using MikroTik SXT's or Ubiquiti Nanostations on the side(s) of the house you want to cover. This will give you about 60 degrees of coverage in said direction. It puts the RF energy in more useful sectors rather than less signal spraying in all directions. Each node needs a separate channel. Note that if someone is close by then they can come in off the side of the antenna. The 60 degrees isn’t a hard cut off. As mentioned below the Ubnt omni's have between 2 and 4 degrees of downtilt, and between 7-12 degrees of vertical beamwidth. So at 15ft high, say a one story roof, the center of a 2Ghz beam is hitting the ground 214ft away. Omni’s can be useful but the area of coverage vs. antenna height must be closely matched. To connect with someone further away you really want dishes pointed at each other. And remember, one tree can ruin your day :)
nc8q's picture
choosing between omni vs. directional antennas?
I feel that choosing an omni-directional antenna is the most common WRONG choice.
If these neighbors are still active, please ask them to update their equipment status via the
Upload data to AREDN Servers
Call, Firmware, last update, device
N7LZD,, 2017-04-01, Bullet
N1RWY,, 2017-05-12, Bullet
K7RWE,, 2017-05-12, Bullet

 Assuredly, things have changed in the last 3 years. :-|

Recently updated:
AH6OD, NB1234, 2020-05-08 hAP (indoor device) on '-2' at 10 MHz BW.
Your GL-iNet was on '-2' at 5 MHz BW when you updated.

 We need to have accurate knowledge of devices, locations, heights a.g.l., before making any recommendations.

Other Nodes
I've been sending out emails to them to get their current status.  
Watch the omni downtilt angle
I learned the hard way that the downtilt angle of the omni pattern does matter at the 3 GHz our nodes run at.  Our first two nodes were about 3 miles apart and I didn't notice that the omni's I bought have a 4° downtilt.  Turned out that I was sending the signal into the neighborhood across the street on one end, and the building's parking lot on the other.  I actually ended up tilting one end over to bring the lobe up to the horizon to get the link to work.  

I've never found a MIMO omni with a zero degree downtilt pattern.

I now use sector antennas, but have used dish antennas for point-to-point links.  

73's and good luck!
nc8q's picture
I actually ended up tilting one end over
Hi, Collier:

 If you live on the side of a mountain
(e.g. Cooper Mountain),
your horizon elevation may not be 0 degrees in all directions.
In this situation it may require an adjustment in elevation which is not convenient with omnidirectional antennas that I am familiar with.
Some panel antenna style devices (Mikrotik SXT series) and most if not all dish style devices are convenient to adjust elevation angle.

I hope this helps,
KE2N's picture
no downtilt, no problem
Very much agree!
Agreed--the variation in elevation angle depending on azimuth needs to be considered in selected a suitable antenna.  My AREDN mesh installs are roughly rooftop to rooftop in Hillsboro so I really needed the pattern pretty much on the horizon.  For my short-term experiment with the omni, I ended up taping some washers together and wedging them between the antenna mast and the antenna mounting bracket.  Not pretty, but worked well enough to prove my theory out.  My primary objective was to tie four EOCs together which are in roughly a triangular area, so the sector antennas were a better fit at each corner.  One corner also pushes signal into downtown Hillsboro where it is linked to one of the county's EOCs using a NanoBridge. 

Thank you and 73's,
KB9OIV There is probably a ton of online calculators. This might help to visualize the math. It's a bunch of trigonometry..I was never that great at that. 'horizon' means that the outer radius of the reach doesn't have a limit.

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