Hi. is there anyone who has try to set a single chain 802.11ac link? I would appreciate some performance feedback from anyone who has expirience on
this setup. I own a RB922UAGS-5HPacD and due to heavy interference environment i am planning to try it on a ptp link (5km) . I know that ac works better with mimo antenna setup
but i already own solid dishes with single polarity feeders. Thanks in advance 
Do you have 4 solid dishes? If so, use them, and rotate the feeders 90 degrees (relative to the “standard ones”) on two of them.
If you just have 2 dishes, make sure you disable the chains not being used on the radios, or at least put a rubberduck antenna on the unused rp-sma connectors so that no chain is left without load.
Its a simple ptp link.One dish per side with single polarity feeder each. Btw it already performes very well on 802.11n link (150mbit lock data rate, 120 mbit bw test ~ 100mbit real traffic with 2 rb433ah with r52nm cards).Of course i’m aware that rb433ah ethernet limits traffic to100mbit. I just want to have some feedback by other users expirience from ptp links with single chain ac,(if there is anyone tested this configuration) regarding data rates, bw test & real traffic throughput etc.The whole concept is to replace the rd433ah with rb922’s without changing the antennas and upgrading the link to ac.Will it worth a try? Any thoughts?
ac has higher spectral density than N, so even a single chain is going to bring you a slight (around 12% if I recall correctly from experience) increase in throughput vs a single chain in N.
For your purpose, instead of replacing with a 922, I’d use a pair of https://routerboard.com/RBGrooveG-52HPacn directly attached to the dishes.
You can build a PTP even with them being L3, and you’ll be able to test the whole link for the price of a single 922.