The Stereo Standard AM Radio Almost Got

In 1980 the Federal Communications Commission was trying to choose one technical standard for stereo sound on the AM radio band — a choice that would have settled what the radio in every American car could pull out of that band. 1

Five mutually incompatible systems were in the running: Harris, Magnavox, Motorola, Belar, and Kahn/Hazeltine, tested over years that began in 1975. 2 On 9 April 1980 the Commission voted 4 to 2 to make Magnavox the tentative single standard. The other manufacturers threatened litigation, and the FCC's own Office of Science and Technology reported that "the selection of Magnavox was not wholly defensible." 3 The tentative decision was cancelled in the further notice of 31 July 1980. 3

The Commission then left the question alone for a year and a half. On 4 March 1982 it announced that no single system would be chosen and handed the decision to the marketplace, leaving four systems standing. 3 The FCC's own account of the period calls it "a bold, new step for the Commission to take," and records what followed: protracted lawsuits, systems fading out, and a delay in reaching the public because "neither broadcasters nor receiver manufacturers wanted to invest in what could be a losing system." 1

The cost landed on the shelf. Manufacturers built receivers that decoded one system or all four, and the multi-system sets cost more and confused buyers. 3 In January 1988 the FCC declined again to pick a standard, with two systems left and 442 of the country's 4,900 stations broadcasting in C-QUAM. 4 At its peak, AM stereo reached about 600 stations, roughly a tenth of the AM band. 3

Congress forced the question in the Telecommunications Authorization Act of 1992, which required a single AM stereo standard within a year. In 1993 the FCC adopted Motorola's C-QUAM — by then in use at 591 stations against 37 on Harris and fewer than 20 on Kahn, with 24 million C-QUAM receivers already sold. 1 By then the music had already gone: AM radio's audience and its programming had moved to news, sports and talk. 5