See 'WikiDevi' @ the Internet Archive (MW XML, Files, Images)
upgraded MW to 1.30 - maybe things are slightly less broken
Belkin F9K1124 v1
AC1900 Wi-Fi Dual-Band AC+ Gigabit Router
A permissive change filing with the FCC suggests that the AC1600 DB Wi-Fi Dual-Band AC+ Gigabit Router (Belkin F9K1119 v2) uses identical hardware.
Chips IDs are illegible in the FCC docs so they are assumed based on specs. Realtek only has one router platform with matching specs currently.
Colocation and DTS reports at FCC say, "Physically, the EUT provides three completed transmitters and four receivers." Looking at the PCB, this seems to apply to the an+ac radio while the bgn is just 3x3:3.
Additional details on routerchart.com but the source of the information is uncear.