Science_and_Invention_Nov_1928_Cover_2.jpg
Varadhan
Summary
Description Science and Invention Nov 1928 Cover 2.jpg |
The television image would be viewed through the cone. The image was 1.5 inches square (4 by 4 cm) and had 48 scan lines at 7.5 frames per second. (This was a low definition "48p" display.) The man is using a 125 hertz tuning fork to adjust the scanning wheel to 450 RPM. By looking through the tuning fork at the line pattern on the hub, he could see when the wheel was at the correct speed. "How to build the S&I Television Receiver" starts on page 618.
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Date | Magazine published November 1928, this page scanned July 2008. |
Source | 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 100 dpi JPG. |
Author | Experimenter Publishing |
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 . 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 Cover.png |
Licensing
Public domain Public domain false false |
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.
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Note: This tag should not be used for sound recordings. PD-1923 Public domain in the United States //commons.wikimedia.org/wiki/File:Science_and_Invention_Nov_1928_Cover_2.jpg |