experimental radio wave detector
date: label: Date made
content: 1912
label: associated date
content: 1912
name: label: associated user
content: unknown
label: associated person
content: Armstrong, Edwin Howard
label: maker
content: Armstrong, Edwin Howard
notes: label: Description
content: This is the main section of Edwin Howard Armstrong's first regenerative radio circuit, constructed in late 1912 while he was a student at Columbia University. On top is a vacuum tube called an "Audion" made by Lee DeForest. Armstrong's research into the Audion's electrical properties led him to a fundamental discovery. He could wire the tube in such a way as to feed the weak received signal back into the circuit. This "regeneration" of the signal resulted in receivers that could detect distant signals and then amplify them so that they could be heard without headphones.
label: Description
content: The invention of radio first involved the transmission and receipt of telegraph dots and dashes rather than voice, hence the term “wireless telegraphy.” The signals tended to be weak and required the operator to wear headphones to hear the signal. Edwin H. Armstrong invented a circuit that allowed people to hear distant radio transmissions without headphones. He built this device around a commercially-available DeForest “Audion” tube in 1913, while a student at Columbia University. The circuit also increased the sensitivity of the receiver and Armstrong received signals from Clifden, Ireland, San Francisco and Hawaii.
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Communications
label: Exhibition
content: Inventing in America
label: Exhibition Location
content: National Museum of American History
creditLine: label: Credit Line
content: from Marion Armstrong
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.314503.07
label: catalog number
content: 314503.07
label: accession number
content: 202631
objectType: label: Object Name
content: Radio Wave Detector
label: Object Name
content: radio receiver
label: Other Terms
content: Radio Wave Detector; Radio
physicalDescription: label: Measurements
content: overall: 17 in x 8 1/2 in x 8 1/2 in; 43.18 cm x 21.59 cm x 21.59 cm