This is the AM Stereo Section of
The Broadcast Archive

Maintained by:
Barry Mishkind - The Eclectic Engineer
last updated 3/2/04

AM Stereo appears to be disappearing from US broadcasting. With the advent of IBOC digital broadcasting, it may soon be history.

AM Stereo broadcasting started as experiments in the 1960s, when XETRA in Tijuana, MX used the Kahn system.

In the 1980s, a war broke out, and a competition between five systems to get the FCC approval as "the" system. First Magnavox was chosen, then sometime later, Motorola. Then a lawsuit led the FCC to declare it a "marketplace decision."  The confusion, along with the continued move of listeners to FM fairly well doomed AM stereo, although receivers are still found in some cars.

Bill Glenn of KGDN has shared some pix of exciters and monitors used.

A BE Exciter
The Motorola
Mod Monitor
The Harris Exciter
The Harris Monitor