on the other post I linked you to the thread here https://forum.openwrt.org/viewtopic.php?id=46859 you won't find that file only in that link cause FriedZombie prepared that file like I said read and...

@beprahst I answered on the other post, how to flash OpenWrt TL-WA850RE I'm pretty much done farting around with this thing unless openwrt is a last resort but that looks like a pain to flash it too....

Read very carefull https://forum.openwrt.org/viewtopic.php?id=46859 FriedZombie it's a Openwrt member that has the knowledge on this subject and will help you along the way

No you need to use 5210 And why you want to replace for 5210s when you have the new 7210

any Tp-Link or UBNT device that you change Channel Width from Auto to 20 Mhz. will drop the rate, read this post from UBNT forum...

upload photos of status of 2 APs to be able to help you did you use this guide to set up http://www.tp-link.com/en/article/?faqid=318