AM stereo is any of a number of mutually-incompatible techniques for broadcasting two-channel audio in the mediumwave band in a manner that is compatible with receivers designed for standard amplitude modulation. There are two main classes of systems: independent sideband (ISB) systems, promoted principally by American broadcast engineer Leonard Kahn ; and quadrature amplitude modulation (QAM) multiplexing systems (conceptually closer to FM stereo), of which the best known is Motorola's C-QUAM.

A famous European transmitter using AM stereo is Villebon sur Yvette on 864 kHz, which tranmits Radio Bleue.

With the advent of digital radio technologies, particularly in-band on-channel systems, AM stereo will likely become obsolete.

External links

• Radio Bleue (French)