Attached is the instruction for switching the AUX1 channel to an XBus port and back for the JR RG613BX receiver. To the best of my recollections, there never was an RG613B (without the X on the end) sold in the US. The X designates an Easy BIND receiver which doesn’t use a binding the plug. The plug that comes with it (which is identical to a binding plug) is used to switch the port.
Allan