Abstract: Stereo audio signals are transmitted over optical fibres in a cable TV system in which stereo radio signals are received and demodulated to produce respective stereo multiplex signals. These stereo multiplex signals are then sampled, digitized and combined to produce a digital multiplex. The digital multiplex is carried over an optical fibre by first modulating the frequency of a video sub-carrier which in turn modulates the intensity of light emitted by a light source. At a switching point stereo multiplex signals are regenerated which modulate FM carriers having substantially the same frequency as the original radio signals.