Audion Amplifier

Year: 1912
Creator: Lee de Forest, Charles Logwood, Herbert van Etten
Company: Federal Telegraph Company
Location: 913 Emerson Street, Palo Alto, California
Room: Radio Valley ↗

Description

This amplifier uses the audion, the three-element vacuum tube that Lee de Forest invented as a radio detector. The illustration comes from a 1914 paper by de Forest about the device.

Importance

From 1911 to 1913 at Federal Telegraph in Palo Alto, de Forest and two assistants used the audion to amplify signals and make radio waves. The state of California marks the site as the place of the first vacuum tube amplifier and oscillator. Later, companies such as Eimac made vacuum tubes in the region.

Interesting fact

In 1934 the U.S. Supreme Court used a 1912 notebook entry from this laboratory to decide that de Forest invented the oscillator.

Sources

Pioneer Electronics Research Laboratory (California Historical Landmark No. 836) ↗California Office of Historic Preservation · 1969-11-03
Perham Collection Creator Profile: Lee de Forest ↗History San José
Radio Corporation of America v. Radio Engineering Laboratories, 293 U.S. 1 ↗Library of Congress (U.S. Reports) · 1934-05-21
Guide to the Perham Collection on Federal Telegraph Company ↗Online Archive of California / History San José · 2012