Abstract: Telecommunication line circuit including a Herter bridge with a first pair of terminals coupled to a bidirectional 2-wire line, a second pair of terminals coupled to an exchange, and a third pair of terminals where longitudinal currents are eliminated from sensed signals, as well as a ringing generator that may be coupled across the second pair of terminals which is coupled to a receive leg of a 4-wire exchange circuit and, through switching means to a ringing generator while the third pair of terminals is coupled to a transmit leg of the 4-wire exchange circuit.