Check the listing for details. Vintage Motorola FM Stereo Decoder/Audio Processing Board. Condition: Used. Listed at 62.99 USD. this is a vintage Motorola FM Stereo Decoder/Audio Processing Board, likely from the 1970s or early 1980s. It was used in professional-grade radio broadcast equipment, such as a studio console or a high-end receiver. Key Identifying Features Part Number: The back of the board (Image 4670) shows the Motorola assembly number 84D83142L04. Audio Functions: The silkscreen labels on the front (Images 4666 and 4667) clearly mark functions for "DE-EMPHASIS," "PILOT STOP," and "PILOT OVERRIDE." These are standard processes for decoding an FM stereo signal into left and right audio channels. Component Era: The use of through-hole components (carbon film resistors, large electrolytic capacitors, and metal-can transistors) points to an era before modern surface-mount technology.