AiMesh or repeater mode with an WiFi 6 (main) and WiFi 5 (secondary) router for extra WiFi coverage?

[Rob Q]

Hi,
My plan is to extend the WiFi coverage for the one side of the house. My main router is the new AX82U but I still want to use my AC1900P since it still works.
I was thinking of using the AC1900P as an WiFi extender but I don't know if I should set it up as an AiMesh node or a repeater?
The AX82U is exposed to the internet, as my modem is connected to the WAN port.
I also want to use the WiFi 6 features with my WiFi 6 devices, so they'll probably be connected to the new router. The older WiFi 5 devices would be on the AC1900P. The AC1900P has got to be connected to the AX82U wirelessly, though. I don't have the spare parts available to wire the two together.

 

[degrub]

put it in AP mode

 

[Rob Q]

put it in AP mode

How would I set that all up?
Ethernet cable?
WiFi?

Also... you mean this? on both or just the one router?

 

[Tech9]

The older WiFi 5 devices would be on the AC1900P

Your RT-AX82U can handle well mixed N/AC/AX devices on 5GHz, RT-AC1900P will be limited to N/AC obviously.

The AC1900P has got to be connected to the AX82U wirelessly, though.

Use the RT-AC1900P as wireless AiMesh node. It will work as a Repeater anyway, but will allow Guest Network propagation.