Hello I need answer from experienced users who has implemented wireless links over 50km.

the best is to use jirous antennas 29dbi dual polarity with some strong card like SR71-15?

Thanks for your reply itdejan. I have only one question for you, did you have implemented this and what was results if you have?

Are you really think that the SR71 card was strong??
During the last 2 years i found only one solution, which really work on 50km
it's 32dbi dual pol antennas+ UBNT RocketM5

Use a link calculator and approach this from an engineering standpoint. Link reliability in the absence of noise is all about gain and margin. You can put gain in antennas or gain in the card, your choice based on tower capability. Any high quality card will do the job. Cheap cards and cheap antennas give cheap quality links. I have good success with MT cards and Ubiquiti cards. Ubiquiti antennas are good but Andrews are the best I have used but pricey. RF Engineering makes great antennas with price points around the Ubiquiti prices. Good luck!

I would use UBNT Rocket Rishes, R5Hn & RB433AH If you have AC power and budget is not an issue put RB800 instead of 433AH.

We have one link, running 62km - but no way to test the REAL capacity of the link (RB433AH can only generate around 30mbit of traffic doing btest from router to router) - and we generate 30mbit - so who knows how fast the link REALLY is - but its rock solid, even with thermal ducting and the like.

i have a link at 45km, i use two antennas by side@34dBi each one, my wireless card is the sr71-15 and my mainboard the rb411ah, the enviroment is very full interfenrency and ubiquiti and many other radios was no work.
my link capacity is 10mbps in both direction and 20mbps in one direction this is the real troughtput.