A method of transmitting sound on the vision carrier of a television system

The paper describes a television system in which sound pulses having a constant height and variable width are inserted in the line synchronizing periods. It is claimed that this method of transmission leads to a simplified receiver and that the programme quality is better in the presence of severe interference. Other advantages are that the frequency band-width for transmission is reduced; the method of receiving sound ensures automatic volume control; the sound pulses provide a fixed reference level for automatic volume control on the vision channel; mutual interference between vision and sound often present on two-channel reception is avoided; reduced transmission band-width simplifies the design of the receiving antenna; mutual coupling between the vision and sound antennae at the transmitter is avoided; and the installation and maintenance costs of the sound transmitter are saved. The frequency range of the system operated in conjunction with the pre-war British transmission would be limited to 5 kc/s.