As the prices are getting lower for 5Ghz equipment, hte frequency looks worse every month.
I have got an idea to apply for a licenced frequency to stop someone from screaming in my dish once in a while and ruining my throughput.
My setup - RB411AH+R52HN <-14 km-> R52HN + RB411AH
the dishes are standard, dual-pol, but since it is so crowded, turning on chain1, slows down a lot.
Anyone has an experience with MT equipment and licencing for higher frequencies?
you can simply configure the link with 6000Mhz and see if it makes any difference. Probably nobody will notice if you turn it on for a few minutes 
another method would be to stay on the same frequency as you are now, but enable Nv2 on both ends. Nv2 is very agressive, it will keep working but others might be affected
Will try that for now.
The actual question is - may I use it legally, after getting licence, if it works? As far as I know, r52hn are certified, but in 5.1-5.8Ghz. ESD.lv requires certified gear for getting a licence. And I really wouldn’t like to go and buy Canopy or Radwin or other mystical brand.
you need to find out what certificate they need. We have CE and ETSI, maybe that’s enough.
The question here is - which version of ROS5 RC should I try?
Always the latest. RouterOS v5rc11 will be released later today, if you want a pre-release, I can give you, email support. It has the most wireles improvements and fixes.
Well, it did solve some accute problems - now I have a stable 20m/20m despite the crowded frequency. Should be enough untill spring is here.
As usual, the best feature throughout every version is MT Forum. 
I have 5 PtP links using Mikrotiks I’ve tried dual-chain with. Here’s my experience on all 5. Nstreme does NOT work well with dual-chain. In fact, some of my 150/150Mbps single chain links got WORSE and dropped to 65/65Mbps when I added the other chain. Other links fluctuate wildly from 162/216Mbps, always changing.
Solution? When I run NV2, ALL links stay at a stable 270/270Mbps, CCQ 100% and throughput is best. I would recommend using NV2 for anyone using dual-chain(pol) PtP links.
Still wish NV2 supported 150 and 300Mbps data rates. Why does it not? Someone said its the “nature” of TDMA protocol, but if that is true then why can Ubiquiti work 300Mbps data rates with TDMA?
Nstreeme work best with dual chain
I should add this
I had the same problem just change the antennas with better ones with more (I mean real) isolation between H/V
I never understood how you can get “good” isolation with a dual-pol feedhorn. I have big enough problems having antenna’s “close” together on the tower, let alone shove 2 different signals out the SAME antenna, and on the same frequency? Even if the feedhorn has good isolation, the signals are still being reflecting on the same dish.
My theory was with MIMO, and NV2 is that the TDMA splits the timing on Chain0 and Chain1 so that they are actually broadcasting at different times and not interfering with each other…
Even if the feedhorn has good isolation, the signals are still being reflecting on the same dish.
It works because the signals are still 90 degrees apart even after reflection, thus maintaining the isolation between them. There is always some minor phase changes and irregularities in the wave front and so it is not a theoretical infinite value of isolation in practise. If the surfaces are very smooth and thus create little signal scatter, then the isolation can be high enough to make these dishes work very well in practise. Also a well designed dual-polarity isolator feed helps too.