Hello.
If the antenna is disassembled, it is evident that the polarization do not meet at an angle of 90 degrees.
An angle between polarization vertical / horizontal is about 80 degrees.
It is the fault of one piece or?
It is: MTAD-5G-30D3-PA
http://routerboard.com/MTAD-5G-30D3-PA
Have you observed multiple units like this or just this one? Could be a once off coincidental manufacturing fault?
I see maybe 1-2 degree difference, not 10 
there will be no operational difference
There is better photo. See.
It is really not 90 angles
I agree, that this seems to be a specific case, manufacturing glitch, but still only some 2 degrees. It should not affect the performance.
We’ll see, we test the performance…
3 degrees cause 1 dB loss … You wont even notice that loss at all
I’m gonna buy few couples for my network, and I believe that I will be satisfacted.
Only thing that I would change is freq.range. It says that this antenna block 5.4GHz and lower and it’s ok, but my network operate in high noisy environment and sometimes when everybody goes to 5500MHz and higher I go to 5180 and it’s free. So it would be much usefully for me if antenna goes from 5.1-5.8GHz.
Thank You
the antenna does cover the range you are looking for:
http://i.mt.lv/routerboard/files/mANT30-140526124123.pdf
From the file: “4.7-5.875 GHz”
mmm yeah, sorry my mistake. Thank You
http://en.jirous.com/antenna-5ghz/jrc-29-duplex
could you make inspiration from this? extra buyable shield (withou it is useless in noisy enviroment) and also pigtails are not covered in mant, the are on direct sun and are heated…and cause losses