I would like to build a circuit that will allow two imputs such as a walkman device etc. that will allow one of the devices to flow through but when it sees a signal from an other unit such as a ham radio it will switch to that imput until the signal stops and then return to the original unit. I suspect that there are stock circuits but this seems the best place to start looking.
Anyone have any good ideas as to how the start.
george
Anyone have any good ideas as to how the start.
george