‎"ROETKEN, A. A. & K. D. SMITH & R. W. FRIIS.‎
‎The TD-2 Microwave Radio Relay System. - [THE PAPER SAVED IN THE WESTINGHOUSE TIME CAPSULE II]‎

‎New York, American Telephone and Telegraph Company, 1951. 8vo. In the original printed blue wrappers. In ""The Bell System Technical Journal."", Volume XXX, October, 1951, No. 4, Part II. The entire volume offered. Pp. 1041-1077. [Entire volume: pp. 1041-1255]. Wear to spine, otherwise very fine. Previous owner's name [Regnar Svensson] to front wrapper. Internally fine and clean.‎

Reference : 43314

‎First publication of the highly influential radio system TD-2. The TD-2 was the backbone of all transcontinental television broadcasting and long distance telephone traffic, before satellite transmission was made possible. This paper is one out of three selected papers from Bell System Technical Journal to be saved in the Westinghouse Time Capsule II. Time Capsule II was created for the 1964 New York World's Fair and is not to be opened until the year 6939, four thousand years after the first time capsule was created. ""The first transcontinental microwave radio system was the AT&T TD-2 route from New York to San Francisco. This system employed 100 repeater stations operating in the 4-GHz band using a 20-MHz channel bandwidth to relay 480 voices channels on a frequency modulated radio carrier ""(Ishii, Thomas Koryu, Handbook of Microwave Technology, 1995, p. 449).‎