Alexanderson alternator [SEP] named after
Alexanderson alternator
An Alexanderson alternator is a rotating machine invented by Ernst Alexanderson in 1904 for the generation of high-frequency alternating current for use as a radio transmitter. It was one of the first devices capable of generating the continuous radio waves needed for transmission of amplitude modulation (sound) by radio. It was used from about 1910 in a few "superpower" longwave radiotelegraphy stations to transmit transoceanic message traffic by Morse code to similar stations all over the world.
Although obsolete by the early 1920s due to the development
Alexanderson Day
Alexanderson Day, named after the Swedish radio engineer Ernst Fredrik Werner Alexanderson and held either on the last Sunday in June, or on the first Sunday in July, whichever comes closer to 2 July, is the day of the open house at the Swedish government VLF transmitter Grimeton, call sign SAQ, located near Varberg. On Alexanderson Day, Christmas Eve, and at other times during the year, the only workable Alexanderson alternator transmitter in the world is used to transmit short Morse messages on 17.2 kHz,