I have a device that requires 2.4 ghz to connect. How do I know if that my WiFi router is putting out the correct signal?
It depends on what Comcast modem you have. Mine is the XB6 and I use a single SSID for both 2.4 and 5.0. You can create a different SSID for each band. (If you have the xFi Pods, you should use a single SSID; my 2.4 devices work with a single SSID)