AT&T coaxial trunkline 1949
Forfatter/Opretter:
Robert Hertzberg
Kredit:
Shortlink:
kilde:
størrelse:
657 x 664 Pixel (203953 Bytes)
beskrivelse:
Cross section of long distance AT&T coaxial cable trunkline used after World War 2 to carry telephone calls and television programs between cities. It consists of 8 coaxial subcables surrounding supporting steel strands. Each coax subcable could carry 500 telephone conversations or one television channel. This was installed January 16, 1949 between Philadelphia and Cleveland to link AT&T networks on East Coast with the Midwest.
Licens:
Public domain
Kommentar på licensen:
This 1949 issue of Tele-Tech magazine would have the copyright renewed in 1977. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. Search of the Renewals for Periodicals for 1976, 1977, and 1978 show no renewal entries for Tele-Tech. Therefore the copyright was not renewed and it is in the public domain.
Yderligere oplysninger om licens til billedet kan findes her. Sidste ændring: Sat, 17 Aug 2024 17:19:02 GMT