1975-04-00 The Appalachain Educational Satellite Project ended.
1975-10-00 Christian Communications Network began (San Diego, part time)
1975-09-30 HBO (Home Box Office) became the first satellite-delivered programming service for the cable industry (PAY).
It send its signal to the United Artists systems in Vero Beach and Fort Pierce, Florida and to American Television and Communications Corp’s (ATC) Jackson, Mississippi system.
Highlight: "The Thrila in Manilla" boxing match between Muhammad Ali and Joe Frazier. HBO leased space on a transponder of a Westar 1 satellite.
1975-12-13 Satcom 1 satellite was launched.
1975-12-23 Channel 68 Los Angeles signed off.
In 1975, James Grabenstein and William O'Neil demonstrate the first use of feed-forward technology to handle expanded channel capacity and higher frequencies. This would make it possible to send channels into the frequency range above channel 13 (as cable channels 23-36 or K-W).
Source: The Cable Center website: Cable History Timeline: http://www.cablecenter.org/resources/exhibits/cable-history-timeline.html