This day, June 17th, in 1936 electrical engineer Edwin H. Armstrong demonstrated a revolution in radio broadcasting - FM!
"Up until the late 1930s, AM (amplitude modulation) radio frequencies were the only ones available for those listening in. The broadcasts were typically full of static and created a problem for engineers to eliminate. While there were many ideas to get rid of the problem, they were met with little success until Armstrong began researching a solution. Through trial and error, he eventually was able to modify the frequency of audio signals and created a 'wide-band' FM (frequency modulation) system.
At a conference of radio experts, Armstrong played a jazz phonograph record first at an AM frequency and then switched to FM. An article capturing this event from the San Bernadino Sun stated: '...if the audience of 500 engineers had shut their eyes, they would have believed the jazz band was in the same room.' It was later described as the most important radio development."

https://en.wikipedia.org/wiki/Edwin_Howard_Armstrong
#radio #history #electronics