DescriptionVladimir Zworykin and historic TV tubes.jpg
English: Russian-American electrical engineer and inventor Vladimir K. Zworykin standing in front of a display of some of the historic television tubes he invented. Working at Westinghouse and RCA laboratories from 1923 through the 1940s, Zworykin invented the first successful electronic-scan television systems, including the widely used iconoscope camera tube.
Caption: "Dr. Vladimir K. Zworykin, with historic TV tubes he has helped to develop."
This 1954 issue of Radio Age magazine would have the copyright renewed in 1982. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. [1] Search of the Renewals for Periodicals for all years from 1978 to the present show no renewal entries for Radio Age. Therefore the magazine's copyright was not renewed and it is in the public domain.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.