Ernst Alexanderson
His whirling alternator became the first machine to send a human voice reliably across the Atlantic, transforming radio from a spark-gap curiosity into a global tool.
1878–1975 (age 97)·Swedish-American electrical engineer and inventor (1878–1975·Birthday: January 25·The Gilded Age
Biography
Ernst Alexanderson arrived in America from Sweden in 1901, a young engineer with a head full of alternating current theory. At General Electric, he faced a seemingly impossible task: building a transmitter powerful enough for transatlantic radio, which then relied on feeble, crackling sparks. His solution was a masterpiece of electromechanical elegance—the Alexanderson alternator, a high-frequency generator with a spinning rotor that produced a continuous, pure radio wave. This machine, installed at stations like New Brunswick, New Jersey, became the workhorse of intercontinental communication for decades, carrying the first two-way voice conversation across the ocean in 1915. Later, his inventive mind turned to war, yielding the amplidyne, a precise amplifier that gave Allied anti-aircraft guns their deadly accuracy. Alexanderson lived to see 97, a quiet architect of the connected world, whose spinning machines laid the wire-less wires for the century to come.
The Gilded Age
1860–1882
Born during or after the Civil War, they built industrial America — the railroads, the steel mills, the first skyscrapers. An era of massive wealth, massive inequality, and the belief that the future belonged to whoever could build it fastest.
Ernst was born in 1878, placing them squarely in The Gilded Age. The events that shaped this generation — world wars, depression, and rapid industrialization — shaped the world they entered and the choices available to them.
#1 When Ernst Was Born
The biggest hits of 1878
Ernst's Life & Times
The world at every milestone
1878Born
President: Rutherford B. Hayes
1883Started school
President: Chester A. Arthur
1891Became a teenager
President: Benjamin Harrison
1894Could drive
President: Grover Cleveland
1896Could vote
First modern Olympic Games held in Athens
President: Grover Cleveland
1899Turned 21
President: William McKinley
1908Turned 30
Ford Model T goes into production
President: Theodore Roosevelt
1918Turned 40
World War I ends; Spanish flu pandemic kills millions
President: Woodrow Wilson
1928Turned 50
Alexander Fleming discovers penicillin; Mickey Mouse debuts
President: Calvin Coolidge"Ol' Man River" — Paul WhitemanBest Picture: Wings
1938Turned 60
Kristallnacht and the escalation toward WWII
Gas: $0.20/galHome: $2,850Min wage: $0.25/hrPresident: Franklin D. Roosevelt"Begin the Beguine" — Artie ShawBest Picture: You Can't Take It with You
1948Turned 70
Israel declares independence; Berlin Blockade begins
Gas: $0.26/galHome: $7,450Min wage: $0.40/hrPresident: Harry S. Truman"Twelfth Street Rag" — Pee Wee HuntBest Picture: Hamlet
1958Turned 80
NASA founded
Gas: $0.31/galHome: $11,050Min wage: $1.00/hrPresident: Dwight D. Eisenhower"Volare" — Domenico ModugnoBest Picture: Gigi
1975Died at 97
Fall of Saigon ends the Vietnam War
Gas: $0.57/galHome: $27,600Min wage: $2.10/hrPresident: Gerald Ford"Love Will Keep Us Together" — Captain & TennilleBest Picture: One Flew Over the Cuckoo's Nest
Key Achievements
- Invented the Alexanderson alternator, the first continuous-wave radio transmitter capable of reliable transatlantic communication.
- Conducted the first two-way radio telephone conversation across the Atlantic in 1915 using his alternator system.
- Developed the amplidyne, a high-power DC amplifier crucial for fire-control systems on WWII naval vessels and anti-aircraft guns.
- Held 344 patents over his lifetime, spanning radio, television, and power engineering.
- His alternator station in Grimeton, Sweden, is a preserved UNESCO World Heritage Site still operational for special events.
Did You Know?
His historic 1915 transatlantic voice transmission featured a conversation between New York and San Francisco, routed via Arlington, Virginia, and the Eiffel Tower.
He filed his last patent at the age of 89, for a color television system.
The call sign of his alternator station in Sweden, SAQ, is still used in annual Christmas Eve transmissions heard by radio enthusiasts worldwide.
He initially worked for GE under the famed inventor Charles Proteus Steinmetz.
“A continuous wave, not a spark, will carry the human voice across the ocean.”
