When it is in repeater function, the router will always be on the same channel as the source. For example, I repeat an access point on channel 11, my 2.4Ghz wifi is on channel 11, I cannot change this because I use the same 2.4Ghz radio in my router but I transmit this signal to 5Ghz radio. So as eric tell you later, you can repeat a 2.4Ghz wifi hotspot and not make a 2.4Ghz wifi signal with your router and go on to transmit with the 5Ghz radio and there you can change the channel as you want, 36, 48, 149 etc…