MR76 antennas

[Adrian4]

Hello,

I need to upgrade some external Mr74's around an industrial site. These are mounted high on the side of buildings to provide coverage into open yards (where material is stored) so people can do stock takes with hand scanners etc.

I have had a walk around to look at the current AP's and I am not sure they are configured properly in the first place. 

As I understand it, the AP has 4 antenna connectors, two on top and two on bottom. Each pair does a separate WiFi band (2.4/5Ghz).

They way some of these APs are setup at the moment, they have two omnidirectional antenna on the left side connectors, and a patch or sector antenna connected to the right side. I assume the logic was that this would mean each kind of antenna was providing both bands but I am not sure it works like that? I didnt think you could have one antenna connecting to both radios?

However, when I walked around with my laptop, I seemed to be getting an ok signal from it so maybe this kind of setup does work?

My other confusion is with the type of antennas - I see you can get sector antenna that are just 2.4 or 5Ghz,

(MA-ANT-23)

(MA-ANT-21)

but you can also get duel band ones like the MA-ANT-25.

Does it mean the duel band ones can be fitted to either radio (but still only one at a time)?
Or does it mean it can be fitted to both radios to transmit both bands at the same time from the single antenna?

Thanks in advance.

[Brash]

Your understanding of the external antenna connectors is correct.

The MA-ANT-25 is dual band and can transmit both bands at the same time. It has 2x N-type connectors to connect to the AP (one for 2.4ghz and one for 5ghz)

This image is a good indicator of what it looks like

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ62IresjJ7LLiswi_NxY7kumwfvdP0Ir7SrYNc3Zxkf1Xf...

[Adrian4]

hmm, but that picture shows one antenna connecting to the 2.4Ghz radio and another to the 5Ghz - so each antenna can only be transmitting a single band?

If each antenna were to broadcast both bands at the same time surely they would need to be wired in so each antenna has a top and a bottom connection?

[Brash · Accepted solution]

You're right sorry, I misread the image.

So yes, they're dual band but can only transmit one at a time.

"Meraki outdoor sector and patch antennas have two integrated cables and N connectors. Both of these connectors must be attached to the same radio. This is important for 2x2:2 APs such as MR74 and MR76. A single sector/patch antenna should not be attached to both the top and bottom of the access point, which would have that antenna connected to two different radios. When looking at these 2x2:2 access points, each radio has two ports next to each other on the same side of the AP. For example, if an MR76 has two ANT-25 patch antennas properly connected, even though they are dual band antennas, one ANT-25 will have both pigtail cables connected to the 2.4GHz radio and the other ANT-25 will be connected to the two 5GHz radio ports."

https://documentation.meraki.com/MR/Other_Topics/Frequently_Asked_Questions_regarding_Cisco_Meraki_A...

[Adrian4]

that FAQ is exactly what I was looking for, thanks!

[JonathanHa]

Hey @Adrian4 ,
I think I have a comparable scope (Handscanner in outdoor area) but the actual operational site is potentially a little too far away from the building. So I am thinking about having a MR76 with a pair of ANT-20 antennes (connected to bottom connection). Because we cannot be sure that signal strength is enough from there, I was thinking about using a second MR76 with a bridge/mesh connection to the first one but now the second one very close to the operating area (pallet storage).

Do you know if this is a "better" solution than only using one MR76 with "full" signal strength?

• Distance from warehouse (1st MR76) to pallet storage entrance (2nd MR76) ~35m

[JonathanHa]