Public domain ↗
Federal Telegraph Poulsen Arc Transmitter
- Year
- 1909
- Creator
- Cyril Elwell, Leonard Fuller (after Valdemar Poulsen's arc design)
- Company
- Poulsen Wireless Telephone and Telegraph Company, later Federal Telegraph Company
- Location
- 913 Emerson Street, Palo Alto, California (first laboratory)
- Room
- Radio Valley ↗
Description
This radio transmitter made continuous radio waves from an electric arc in a strong magnetic field, after a design by the Danish inventor Valdemar Poulsen. Federal Telegraph made this 5-kilowatt unit for the U.S. Navy during World War I.
Importance
In 1909 the Stanford graduate Cyril Elwell received a license for the Poulsen arc and started a company in Palo Alto. As Federal Telegraph, the company sold arc radio systems to the Navy and had more than 300 employees by 1917. In its laboratory, Lee de Forest later made the audion tube into an amplifier.
Interesting fact
Federal Telegraph gave Ernest Lawrence a large arc magnet from a canceled Navy order, and it became the magnet of his first large cyclotron.
Sources
- Perham Collection Creator Profile: Federal Telegraph Company ↗History San José
- Guide to the Perham Collection on Federal Telegraph Company ↗Online Archive of California / History San José · 2012
- Oral History: Leonard Fuller ↗IEEE History Center (Engineering and Technology History Wiki) · 1976-05-29
- Valdemar Poulsen: Federal Telegraph Company Arc Wireless Station (reprinted from Pacific Gas and Electric Magazine, July 1912) ↗Museum of the City of San Francisco · 1912