C-QUAM

C-QUAM (Compatible Quadrature Amplitude Modulation) is a technology used in AM radio broadcasting to transmit stereo sound and improve audio clarity. It works by adding a second audio signal that is shifted in phase, allowing radios equipped with C-QUAM to decode and reproduce stereo sound from AM stations that traditionally only transmitted monaural (mono). This method maintains compatibility with standard AM radios that only understand the basic signal. Essentially, C-QUAM enhances traditional AM broadcasting, enabling richer, stereo audio while ensuring compatibility across different radios.