English: The Portaphone was a prototype radio receiver that was designed by the U.S. Bureau of Standards in Washington, D.C.
Original caption: "Portaphone with case open to show the loop antenna and detecting and amplifying apparatus."
Date
Source
Illustration included in the article "The Portaphone--A Wireless Set for Dance Music or the Day's News" on page 571 of the May 22, 1920 issue of Scientific American.
Author
Uncredited photograph provided by the U.S. Bureau of Standards
Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country. Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Portaphone_radio_receiver_(1920).jpg
Captions
Add a one-line explanation of what this file represents