Ernst Alexanderson: From Spinning Machines to Moving Pictures

Sourced history

A Book Opens a Path to GE

Born in Sweden on January 25, 1878, Ernst Alexanderson studied engineering in Stockholm before continuing his education in Berlin. There, Charles P. Steinmetz’s book Alternating Current Phenomena inspired him to seek an opportunity to work with its author in the United States. General Electric hired Alexanderson as a draftsman in February 1902 on Steinmetz’s recommendation. He took the company’s Test Engineering Course the following year, and in 1904 joined the engineering staff designing generators under Steinmetz. His early inventions included a reverse-current relay intended to protect power systems against short-circuit faults. Radio would soon present a very different assignment.

Sources: [1][3]

Sourced history

Building a Machine for the Human Voice

Radio experimenter Reginald Fessenden needed a transmitter capable of producing continuous waves suitable for carrying sound. He turned to GE for a high-frequency alternator, and the challenge of developing a faster, more powerful machine fell to Alexanderson. The work demanded more than simply increasing speed. Rapid rotation could deform a disk and change its electrical properties; air friction generated heat that threatened copper and solder. Alexanderson developed an empirical formula for the air-friction loss of a rotating disk while pursuing the alternator. After two years of experimentation, his machine helped make possible Fessenden’s Christmas Eve 1906 broadcast from Brant Rock, Massachusetts. The program included speech and a violin performance.

Sources: [1][2][4]

Sourced history

From an Experiment to Ocean-Spanning Communication

Alexanderson continued improving the alternator. It became an important transmitter for commercial and naval stations sending radiotelegraph messages across intercontinental distances, before vacuum-tube transmitters displaced it by the 1930s. His work extended beyond transmitting machinery. A selective-tuning receiver system patented in 1916 became widely influential in radio. He also developed magnetic and electronic amplifiers, antenna systems, and radio altimeters. In 1919, Alexanderson became chief engineer of the newly formed Radio Corporation of America. Until 1924, he divided his work between RCA and GE, keeping his home and laboratory in Schenectady while overseeing construction of powerful radio stations in locations including Sweden, Poland, England, and Hawaii.

Sources: [1][2]

Sourced history

Pictures Join the Signal

Returning to GE full-time in 1924, Alexanderson pursued technologies for transmitting pictures. He began experimenting with television in 1925, and in 1926 sent a facsimile picture from the United States to Europe that appeared at the receiving end in two minutes. In 1927, he demonstrated television reception in his Schenectady home using high-frequency neon lamps and a perforated scanning disk. The following year, he worked on coordinating sound and movement for the television drama The Queen’s Messenger. In 1930, he publicly demonstrated a large-screen television system over a closed circuit at Proctors in Schenectady.

Sources: [2][3][4]

Sourced history

An Inventor Beyond Broadcasting

Alexanderson’s inventions also reached railway electrification, motors, power transmission, telephone relays, and electric ship propulsion. His amplidyne, a direct-current amplifier, was used to control anti-aircraft guns during the Second World War. Retirement from GE in 1948 did not end his research. As an RCA consultant, he continued television work, and in 1955 patented a color television receiver. He died on May 14, 1975, aged 97, and was inducted into the National Inventors Hall of Fame in 1983.

Sources: [2][3][4]

Commentary

Historical Perspective: Innovation Across Boundaries

In our view, Alexanderson’s significance lies as much in the connections between his projects as in any single invention. His career offers a compelling way to understand GE’s legacy: expertise developed for one problem could become the starting point for another. For heritage audiences, this is a reminder to look beyond the finished apparatus. Experimentation, technical education, collaboration, and persistence deserve a place alongside the celebrated breakthrough. Alexanderson’s story invites us to see industrial invention not as a series of isolated triumphs, but as a continuing exchange between fields.

Sources

[1] Ernst F.W. Alexanderson – Edison Tech Center — edisontechcenter.org
[2] Ernst Alexanderson - Wikipedia — en.wikipedia.org
[3] Ernst Alexanderson | Lemelson — lemelson.mit.edu
[4] NIHF Inductee Ernst Alexanderson and Radio Communication — invent.org

Written in original words with AI help from the sources above and automatically checked against them. Facts, quotations and commentary are labeled separately; credit belongs to the original authors. GE Heritage Village is independent and not affiliated with GE or Crotonville.