Thank you for advice, I will try to install given package from your link. But as Atheros wifi dongle was not as stable as Ralink one on turris I would like to make that Ralink WIFI USB working again at the first place.After upgrade it looks like it should work but as I wrote no 2.4GHz network from this USB dongle on air…
UPDATE: There was obviously some garbage configuration problem or whatever. Yesterday second wifi malfunction forced me to wipe my Turris 1.0 NAND and flash actual image from SD card. After reinstallation it seems like 5Ghz internal wifi is working without interruptions and external Ralink WIFI USB dongle started working back again. So fresh installation solved my problem.
I done
opkg update
opkg install kmod-rt2800-lib kmod-rt2800-usb kmod-rt2x00-lib kmod-rt2x00-usb
to make USB wifi working again.