Edwin Howard Armstrong, the father of FM

It's now the 75th anniversary of the development of Frequency Modulation by Edwin Howard Armstrong.

The story begins in 1904 when his father gave him The Boys' Book of Inventions and following year a publication entitled Stories of Inventors. At age 14 he told his parents he wanted to become an inventor.

Inspired by Faraday, Marconi and others, he experimented with wireless telegraphy, later holding the office of President in the Radio Club of America.

While an undergraduate at the Columbia School of Engineering in 1914 he created the regenerative circuit, using a triode tube invented in 1906 by Lee De Forest.

In 1917 he enlisted in the army signal corps to be stationed in France testing and developing radio equipment.

He returned home for a 19-year legal battle that ended with the regeneration method awarded to De Forest.

Armstrong had moved on, developing the super-heterodyne receiver. Then he took out a patent for wideband FM on the 26th of December 1933.

In 1936 he set up FM stations and amazed the public by their broadcast quality. In 1940-41 he helped adapt FM for mobile military communications.

To keep his FM broadcasting dream going he started court action seeking unpaid royalty payments on FM radio receivers. Armstrong was financially ruined, depressed and he ended his life in 1954 aged 63.

His wife Esther continued the battle to gain millions of dollars for patent infringements.

Edwin Howard Armstrong, a genius, the father of FM, did more than anyone other individual to develop radio technology which the world enjoys today.


Jim Linton VK3PC
Wireless Institute of Australia