June 14, 1921 - New Haven amateur radio operator Franklin M. Doolittle sold his federal patent application for "Sound Recording and Sound Reproducing and Locating Apparatus" to the Radio Corporation of America (Serial #477,360).

Doolittle was the founder of New Haven, Connecticut's radio station, WPAJ. It was renamed WDRC in 1925 and moved to Hartford in 1930. Click here to read about Doolittle's other patents: 1924, 1927 & 1931.