Armstrong and the FM Revolution

Abstract

This chapter unravels Howard Armstrong's creation of wide-band frequency modulation — FM. It follows a trail of research from hundreds of thousands of tests and measurements, tens of thousands of hours of work for Armstrong and his assistants, to ultimate triumph. Like most revolutions, Armstrong's FM had been a long time in the making. The chapter argues that Armstrong began exploring the nature of frequency modulated waves in as thorough a way as he had the operation of the vacuum tube and the phenomenon of static. The chapter then tracks Armstrong's fundamental changes in the radio receiver. The chapter investigates the challenges and hearings faced by Armstrong. It became clear to all in radio that new portions of the spectrum were needed for television, police, and government communications as well as FM. The chapter then recounts how the introduction of FM began to move more swiftly.