Wondering about Interfearence with Multiple A5c's and KP Antennas


#1

Hello all,

My Company and I are looking at creating our first long range site. We have had success with short range using the A5 and A5c’s using the N5360 Antenna. Basically now we are getting into long range, and I am curious about interference. We are going to be using 3 A5c’s along side 3 KP Performance 65 Degree 5Ghz Panels. We are looking at purchasing an engineered Non penetration roof mount (Which is quite expensive) and what I am wondering is if anyone has ever had 3 Antennas/Radios on the same 10 foot pole. I have been told by KP Performance that they recommend each antenna be at least 10 feet away from one another. Obviously if we were to do that we would require 3 different mounts and the cost could become substantial. I have looked into potential RF Shielding but KP does not make any sort of shielding for their panels. At this point I am looking for ideas as to how we could go about doing this. Worse case scenario we would be willing to purchase the 3 mounts, just wondering if anyone has any ideas.

Thanks!


#2

Hello Connor,
Please take a look at our new N5-45 antennas, designed specifically for these type of scenarios. https://mimosa.co/product/n5-45 They have the best front-to-back ratios in the market. Thanks,
Hector


#3

Hi Hector, I have seen them already. The issue here is we have already purchased the KP Panels. So we need to make this work with those.


#4

So, ya, we didn’t follow KP Performance’s recomendation:

We have been running this for over a year. 140 ft up in the air, customers upto 7 miles out (Would not recommend that far unless you are willing to spend more then $300 for client equipment, C5c, 25-30 dB antenna and a mount to hold it properly. You can do it for less, but you will pay for it somewhere, I would cut out around 4-6 miles depending on how much noise you are dealing with.)

If you will be using SRS, your self interference problems will be minimized, but make sure you don’t have FM, AM or other noisy radio sources nearby because that will mess with your GPS and then you will have issues. (If you have A5s in the area that are not having a problem, then you should be fine.)

Here is the Spectrum View from the Radio facing the camera:

The noise on the high end of the spectrum are the other 3 sectors and some other equipment in the area. The noise closer to the in use channel is another sector on a pole 3 feet away facing in the opposite direction.


#5

Thanks William, I am thoroughly impressed with that setup. Glad to hear that KP’s rule isn’t set in stone and there are work arounds. Thank you so much for the advice and proving that it is possible. You have saved us a lot of time and money. I will give it a shot and in the next few weeks after testing I will post my results!


#6

No problem, KP doesn’t make the rule for no reason, be careful with your channel planning and follow Mimosa’s GPS Sync design guide. Channel size is another big factor for going distances. If you want to use anything over 20 MHz, you will cut your distances by at least a third or double your CPE cost.

Also those 65 antennas have a built in 5 degree down tilt. Unless you are shooting uphill, don’t tilt them up, big mistake that gives really weird dead spots as you get further out. Play with Mimosa’s Network Design Tool to see what I mean.

Also, the 65 Antennas can have a pretty sharp cutoff. You will setup one customer on the antenna with a good signal and a quarter mile down the road not be able to hold a signal. Some signal overlap is not a horrible thing especially when you have channel space available.


#7

Thanks William, I will take these into consideration and implement them accordingly. Honestly I have gotten more answers here from you than I have from any of Mimosa’s Reps or KP’s. Very excited to set this up. Will keep you posted. Thanks again big time!


#8

Their Job is to tell you what I am doing is not the best idea, up to recently it really wasn’t. Until TDMA, well isolated antennas and clean transmit signals hit the scene self interference was a killer. Now a days, you see guys doing 360 degrees of 30 degree horn sectors stacked on top of each other.

We could never have done this with the Ubiquiti M5 equipment, we tried running a couple of our A5c sectors in WiFi Interop, didn’t work at all. Even with just 1 sector in Interop we had problems.

The A5 has really clean transmit (better then Ubiquiti IMO) the GPS “just works”. And the side and back lobes are really small compared to so many other antennas.

Honestly if you are worried about it, I have seen some guys wrap the sides and back of their antennas with copper/aluminum tape that they grounded. Seems to work for them, I have not done it, can’t say much more.


#9

I can definitely say that Mimosa seems to be killing the Ubiquiti M5 Equipment. I used to work for a company that swore by ubiquiti and they couldn’t even compare to the signal and speeds i’ve seen off of a Mimosa Antenna.

In a last resort scenario I may consider the copper/aluminum tape if it gets that bad. Or inquire about another engineered mount. I’ll try the tape before we throw 1000’s on a new mount.


#10

“Good Luck” (Marco “Taken” 2008)


#11


Hi. Not the best photo, but this what i’ve done and works well. I do have shields which I had made to be installed though, to try and reduce self interference a little during busy periods. But working fine without shields, just pick your freq’s.