File:Science and Invention Television 1928.jpg
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Summary
| Description |
English: A woman watching an early homemade experimental mechanical television receiver in 1928, from Hugo Gernsback's magazine Science and Invention. During the 1920s some radio stations began broadcasting experimental television programs, which could be viewed by mechanical "televisor" receivers like this one. The video signal from the receiver (left) is applied to a neon lamp in the viewer (right). In front of the lamp a metal disk with holes rotates, creating the scan lines of the image. This created a dim monochrome orange image 1.5 inches (4 cm) square with 48 scan lines at 7.5 frames per second, visible within the viewing cone, which the woman is watching. These mechanical-scan television technologies never achieved images of sufficiently high quality to catch on with the public, and were superseded by electronic scan television broadcasts in the 1930s. Page scans of the above article How to build the S&I Television Receiver on Commons:
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| Date | November 1928. This page scanned August 2008. |
| Source | Science and Invention magazine, November 1928, Volume 16, Number 7, cover, published by Experimenter Publishing Co., New York, NY. This page was scanned by User:Swtpc6800 on an Epson Perfection 1240U at 300 dpi with half-tone de-screening enabled and stored as TIFF. The image was cropped and touched up in Adobe Photo Elements 5.0. This copy saved as a 150 dpi JPG. |
| Author | Unknown author |
| Permission (Reusing this file) |
This 1928 issue of Science and Invention would have the copyright renewed in 1955. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. http://onlinebooks.library.upenn.edu/cce/ The search of the Renewals for Periodicals for 1954, 1955 and 1956 show no renewal entries for Science and Invention. Therefore the copyright on the magazine was not renewed and it is in the public domain. Science and Invention ceased publication with the August 1931 issue. A search of the copyright renewal records from 1951 to 1959 shows no entries for Science and Invention. All issues are in the public domain. |
| Other versions | Image:Science and Invention Nov 1928 pg618.png |
Licensing
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This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs.
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This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
 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. |
File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 17:45, 9 August 2008 | | 1,138 × 633 (217 KB) | Swtpc6800 | A slight adjustment of the rheostats and the picture come in clearly. This photo shows the complete television receiver connected to an ordinary radio set. The picture is seen in the cone. == Summary == {{Information | Description= A slight adjustment |
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