File:Early 1920s radio and horn speaker.png
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editDescriptionEarly 1920s radio and horn speaker.png |
English: A drawing of an early vacuum tube regenerative radio receiver and horn loudspeaker, the Paragon receiver, made by Adams-Morgan Co., Montclair, New Jersey, USA, from an advertisement in a radio magazine around 1922. The radio consists of two units; the single tube RD-5 regenerative receiver (left) and the two tube A-2 audio amplifier (right) to drive the Magnavox speaker. Before broadcasting began around 1920, radio listening was a solitary hobby, so most radios didn't produce enough power to drive speakers and earphones (on top of set) were used, so only one person could listen at a time. After broadcasting began, manufacturers began adding amplifier units and loudspeakers to their radios to cater to the desire of families to listen to radio together. Vacuum tubes had low power output, so horn speakers were required to get enough volume to fill a room; a disadvantage of this was horns cut off bass frequencies so they sounded "tinny". Most radios of this vintage ran off batteries; this one came with a 22V "B" battery for plate supply and a 6V rechargeable lead-acid battery for filament current. |
Date |
before 1922 date QS:P,+1922-00-00T00:00:00Z/7,P1326,+1922-00-00T00:00:00Z/9 |
Source | Retrieved February 13, 2013 from Charles William Taussig, James C. Edgerton (1922) The Book of Radio, D. Appleton and Co., p. 146, fig. 135 on Google Books |
Author | Charles William Taussig |
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editPublic domainPublic domainfalsefalse |
This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
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This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
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current | 20:32, 13 January 2014 | 1,159 × 845 (155 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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Horizontal resolution | 28.35 dpc |
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Vertical resolution | 28.35 dpc |
File change date and time | 07:20, 28 February 2013 |