"This Report Comes to You by Way of San Francisco" by Jack Van Wart, Broadcast Engineers' Journal, August 1945, page 16. (americanradiohistory.com) The author claimed that "The correct information is that they are G E C which were originally intended to stand for General Electric Co."
Included in the NBC archive at the Library of Congress is a June 12, 1964 memo reviewing the history of the NBC chimes. At some point someone added a handwritten comment that the last use of the "fourth chime" was in 1985 "when GE announced its merger with RCA". However there is no documentation that this actually happened. "NBC Chimes Documents, 1950-1978"
"Trade-marks Published for Opposition (Act of 1946): Service Marks", Patent Office Official Gazette, January 17, 1950, page 655. Application by the National Broadcasting Company, Inc., serial no. 541,873, filed November 20, 1947, categorized as "class 104 (communications)".
Michael Shoshani, at his site "The NBC Chimes Museum", contends that the notes produced by the manual chimes were generally "C-F-A" rather than "G-E-C", and it was only after the switch to the Rangertone devices that the NBC chimes became "G-E-C".
