I have two Mikrotik boards connected to each other,but i had a problem that the tx/rx signal changing between -58 dbm and -74dbm and causing bad connection between the 5GHz links. The two cards are Atheros AR5413. And also the signal to noise sometimes drop to 10 db. Moreover what is the best voltage value to have in >system >health? I had upgraded ther RouterOS to version 5.19 on both boards and still a little confused about the best wireless protocol to use? also i had one of the grid antennas rusted do it affect? I seriously looking for a solution to this problem.. hope for reply.
Have you checked the connections on the antenna are they clean + dry & free of rust the same from radio card to antenna,
Thx a lot! I checked and changed some of the connections and i get a huge improvement in my link quality, but still have a little problem with disconnection ..about every 30 minutes the two link disconnect .. and i think it is from the voltage. How much voltage i must have on the boards?and which wireless protocol should i choose? sorry for my english language and hope for reply.
Voltage above 28volts can cause problems for Routerboard you need to monitor what voltage the board is getting, also check your logs and make sure wireless is listed in the logs if not add to it, Wireless protocol you use is really up to what type of traffic it carries and distance it covers but what is important to select on the station side of link is not “any” but “nv2, Nstreme, 802.11” this will track quickly any changes to the AP wireless protocol,
Thx for your help again.. i checked the log and i’m gettting “disconnected, extensive data loss”, btw using nstream with my link is better than nv2 .When using nstream ping is stable at about 5ms not like nv2 where i’m getting high pings (400,500) and not stable. Don’t know why nv2 is causing problems to me although other users happy of it 
Have you disconnections when using nstreme
yesterday i was using unspecified protocol on the ap side and any protocol on the station side but now i changed to nstream on both sides and didnt get any disconnections (about 1hr) with a stable ping.. but yesterday i heard the clients having bad connection (disconnections) i wasn’t watching it , i want to know how it differs using nstream from unspecified knowing that unspecified chooses nstream?
I would first suggest sorting out the stability of the link and then address client disconnects, as mentioned about station which also applies to customers CPE’s is use wireless protocol “nv2, Nstreme, 802.11” and not “any or unspecified”
Thx for you help i appreciate it a lot… I have a good stable link now and i have some other problems i will post it later
Good to read the link is now stable, another tip give Karma to those who are helpful, it works for me?