Dr. Ernst Alexanderson was the General Electric engineer who built a high-frequency alternator (a device that converts direct current into alternating current) that greatly improved radio communication. Prior to Alexanderson' alternator, radio was broadcast by what was called spark machines that used dots and dashes of signals or morse code. Ernst Alexanderson's alternator allowed radio to be broadcast in a continuous wave. Ernst Alexanderson was issued U.S patent #1,008,577 on 22 February 1916 for a selective tune device for radios that became an integral part of modern radio systems and led to his being honored in the Inventors Hall of Fame. He was also General Electric's most prolific inventor, receiving a total of 322 patents.