The Alternator That Sang: Alexanderson's Giant Machines Early valves were too weak for transatlantic power and sparks too dirty. This guide explains Ernst Alexanderson's alternator: a slotted steel rotor generating the radio wave directly, as pure as clockwork. Quick facts Designer Ernst Alexanderson Output up to 200 kW Flagship Grimeton - SAQ Opened 1924 Survivor still transmits yearly The alternator stations were the heavy industry of interwar radio, and Grimeton's survival as a working heritage station is unique. Its twice-yearly Morse transmissions are logged by thousands of hobbyists - a machine-age ritual, kept on schedule. See the chart: https://morsecodeworks.com/ Morse Code Works - free Morse code tools and guides. Reference chart