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gcs
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2-3 antennas on 1 card

Wed Sep 28, 2011 12:37 am

I always used RB433Ah with 3 radio cards. Usually 1 for 5ghz backhaul, 1 for 2.4 Internet and 1 for 900 Internet. i now want to use sectors in the 2.4 bandwidth. Can you use 2 to 3 antennas on one card say a R52H? What about interference and power loss to the antennas? It would be easier to just replace the Omni with the sectors and not have to reprogram the Rb433 and use more ip address and routes.

Let me know your experience good or is it a bad idea .
 
0ldman
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Re: 2-3 antennas on 1 card

Wed Sep 28, 2011 5:36 pm

I was advised to never put the same frequency cards in the same box. I did it anyway and now I have to go back and swap out my 433 with 3 card for individual units.

Self interference isn't too much of an issue when you start. Once you start to load up the AP you'll have people active on each sector and cause all sorts of problems.
 
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ne0031
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Re: 2-3 antennas on 1 card

Wed Sep 28, 2011 5:56 pm

Following your description.... don't "split" an omni into multiple sectors on the same radio. You didn't actually accomplish anything other than spending time and money.

When sectorizing a site, each sector needs its own radio. With Mikrotik, running on the same freq for client access isn't the best option. There are 3 non-overlapping channels, use them. Also use quality pigtails, jumpers, etc. There have been been discussions on the topic of multiple radios in the same band in a single enclosure. Yes it works - if you know what you are doing.

If you are running an omni today, and you haven't dealt with any hidden node issues, then sectorizing should only continue to enhance your deployment.
Matt

ABC/WXYZ - you get the picture.....

150khz-110ghz
1/5sps to 4gbps
 
gcs
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Re: 2-3 antennas on 1 card

Wed Sep 28, 2011 6:53 pm

Thanks foe the info. Just to clarify. I am look at a new site. A water tower 100' at the catwalk. I thought a panel would be best since the dome of the water tower would seperate the signal from each antenna. So it looks like using a RB433ah with 3 cards and 3 120 degree sectors would be best. Then a second Rb433ah for the back haul and any other radios I want to add like 900.

Thanks again
 
ah2480
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Re: 2-3 antennas on 1 card

Wed Sep 28, 2011 11:37 pm

For our APs we are starting to use the 711As, one per 90° sector. Four sectors per tower. This works well for us.

In your case, I would use RB-411As with XR2s for the APs. But still go with multiple sectors.


EDIT: Of course, I read your post after posting my response. We use 5Ghz for all of our towers, 2.4 is too crowded here. 900Mhz is even worse.
 
WirelessRudy
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Re: 2-3 antennas on 1 card

Thu Sep 29, 2011 3:23 am

You can run two sector antenna's of one card.
It only has to be a ´n´ (or mimo) able card with two chains.

You can connect a sector to each of the chains (=connectors) of the card. They both run in full sync and on both you get the full power of that chain.

For instance, with an R52Hn you get twice 21dBm on each chain. It works perfect. I have on AP like that with 35 customers.

The big advantage compared to using a splitter (which is the ´old fashioned way´) is that you don't have the splitter loss (half the power) plus the extra connector losses.
Compared to separate radio's for each sector you now also save on one frequency.
This system works also better if you for instance where thinking of 2 180º sectors. By splitting each 180º in two 90º sectors (side by side or opposite of each other in a 4 sector setup) you also get better gain over the same ´pie´. Because to get a similar gain on a 180º it has a smaller vertical beam as a 90º antenna so in the latter you have also better service to a broader range, depth wise spoken.

Side advantages are that instead of two cards you can now do with one. Less power consumption and less heat production.
You can now easy use a rb433 with three cards. One backhaul in 5Ghz for instance and two of these dual chain cards both with their frequency with as much as possible separation to serve in total 4 sectors!

In my setup I use two 90º RSLL (Reduce side lob) antenna's and they are only 1 meter apart from each other and covering a total of 180º!

Because both antenna's are now in full sync (they are connected to the same card and both chains of it share the same clock cycle) there is no self interference.
The only thing that might happen in theory is that at some distance and in a very small beam both radio waves that are in complete phase with each other could become in a 180º phase shift because of the different path length (half a wave difference). You would get a "zero" amplitude wave. So this could be a small ´black´ spot.
In reality the change you would have a client just in that spot would be small. Also because the area will be a bit dynamic due atmospheric circumstances that have influence on the radio waves.

It works like a charm with me and haven't come across any negative side effects yet. :D
Show your appreciation of this post by giving me Karma! Thanks.

Rudy R. Puister

WISP operator based on MT routerboard & ROS.
 
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paams
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Re: 2-3 antennas on 1 card

Thu Aug 03, 2017 10:05 am

Hello There! I have done a PtP wireless links with router board RB433 with two wlan cards R52HN (dual chain). I have done ap-bridge wireless configuration mode on RB433 board and station bridge on the another sites. All the other station sites are at different directions. So i decided to utilize the dual chain R52HN radio cards with single chain 24dBi grid antennas for different location based station directions that is four different directions with chain0 connectors to two directions and chain1 connectors to another two station directions. For chain0 link connectivity at station end i have used Mikrotik groove52Hpn having single chain0 and link connected good with Rx/Tx signal strength -65/-63dBm. For chain1 connectivity i am using Mikrotik dual chain DISC Lite 5 with activating both chain0 and chain1 on this station end, as there is no radio with single chain1. But chain1 is not making link from AP base site to this dual chain DISC Lite 5 station. It must work at least with chain1 on this dual chain DISC Lite 5 station. Why this is so it must detect the station and get connected? Any link connectivity technical support will be appreciated from Mikrotik Wireless Network Exert here. Thank you very much.
 
mistry7
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Re: 2-3 antennas on 1 card

Thu Aug 03, 2017 11:34 pm

This doesnt work, you can not splitt 802.11an / ac Cards in this way!

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