Hi,

So the question is in the subject. If I have a mounting pole, and need to have two SXTs on it.

1) Scenario 1, they are facing opposite directions. One to one side, other to other side. PTP links. What should be the vertical distance between them, so there is no intereference (or acceptable interference)?

2) Scenario 2, they are facing almost the same direction, or let's say 60 degrees angle. PTP links. The same question.

What do you have in practice, up and running and working?

Sure you can operate them on the same pole. But you have to use quite big frequency gap to avoid interference. Mount them as far apart as possible also. At least 30-40cm between. SXT is a CPE, not intended for corporate use on masts with many antennas. As much as I'd like to use them for near p2p links, I accepted that it's simply not for that purpose. If you need good noise cancelation - use drums.

By the way, we have one sxt hanging on our main tower together with 4 sectors and while scanning the air from the distance of 1km, we get signal strength upto -71. The sxt is facing the complete opposite direction. So imagine front-to-back ratio

Hi! Thnx for the answer!

I just didn't understand this situation:

By the way, we have one sxt hanging on our main tower together with 4 sectors and while scanning the air from the distance of 1km, we get signal strength upto -71. The sxt is facing the complete opposite direction. So imagine front-to-back ratio

You mean -71, 1km behind SXT??!

Yeah, thats right. It's completely 180deg -71 from ~1km. From ~630m I saw ~-65 to the same SXT also from behind. I've taken some screenshots to show my colegue in case he doesn't believe me..

Mostly sxt's operate in station/st bridge mode, so they don't show up in scans and no one notices this flaw. But put it into bridge mode and here you go, 400mW of pollution to all directions Take into account that you operate at least couple of hundred of them in your area, how it all ends up?

Yeah, thats right. It's completely 180deg -71 from ~1km. From ~630m I saw ~-65 to the same SXT also from behind...

If there is another 5GHz antenna mounted close to the SXT, that could explain it.

Yeah, thats right. It's completely 180deg -71 from ~1km. From ~630m I saw ~-65 to the same SXT also from behind...

If there is another 5GHz antenna mounted close to the SXT, that could explain it.

i agree. you are getting a reflection from something. what were you using to scan?

There are many antennas mounted close to the sxt. But none of them are pointing to this direction, maybe except a 90deg MARS sector. Either way it's not healthy behavior for sxt, in my opinion. Soon I'm going to replace it with high quality panel antenna, and shall see how it all changes. As for clear reflections, I'm not sure it's possible, because there are only vast fields in front of it and not much in other directions.

I think the best way to be sure about all this, is to put a sxt to some neutral place, set it to bridge mode and drive around while scanning with for example another sxt. Unfortunately currently I have no means nor the time for that.

Scanning was done from clients or mobile testing equipment.

There is definitely something to this. I had two SXTs set up in my office around 20 feet apart but the TX power was set to 3. Spinning the SXTs 180 degrees so they were no longer facing each other did not reduce the signal strength at all and the link remained perfectly stable. Something tells me these aren't as directional as they appear to be.

They are directional, but simply don't have properties of really good antenna. Overall, they are the best we can get now for CPE. It'd be good to see them improve more over time.