A method of, and apparatus for, the remote transmission of signals over a line, especially via an electrical energy supply network, wherein at the transmitter there is formed from a first auxiliary frequency delivered to the transmitter a signal frequency which is in a predetermined first relationship to the first auxiliary frequency, an auxiliary signal characteristic of the first auxiliary frequency and the signal frequency are transmitted via the same transmission channel or via different transmission channels to at least one receiver, and at the location of the receiver there is formed from the signal characteristic of the first auxiliary frequency a second auxiliary frequency which is in a predetermined second relationship to the first auxiliary frequency, and such second auxiliary frequency is delivered to a sampling filter for controlling its throughpassage characteristics.