A Webster wire recorder, from the Roger Bellow collection
Early magnetic recorders included the Poulsen Telegraphone of 1898, the Stille Dailygraph of 1925, and the steel recorders developed by Semi Joseph Begun at the C. Lorenz Co. in 1939. Marvin Camras graduated from the Illinois Institute of Technology in 1939 and began working for Armour Research Foundation in Chicago on a wire recorder that was demonstrated in 1940. While developing the recorder he re-discovered high frequency biasing that improved the signal-to-noise ratio by adding to the recorded sound a high tone above hearing level. Although this technique had been patented in 1927, Camras was awarded a patent in 1940. After World War II began, the Navy bought his recorder for military use in the field. The Armour Military Wire Recorder proved to be reliable, compact, portable; it ran on small batteries and the wire reels could be reused. General Electric manufactured the recorder under license from Armour and Camras became head of a new team to produce the recorder for the industrial and educational market. In May 1944, Armour created the Wire Recorder Development Corporation under Lucius Crowell to join GE in the production of about 1000 recorders for the military during the war. During the war, Armour licensed a number of companies to make wire recorders, such as Utah Radio and Radiotechnic Laboratories (also known as the Pierce Wire Recorder Co. that subcontracted from GE). Webster-Chicago Corp. was one of the first 6 licensees in 1943. After the war, Armour continued to license companies like Webster to make wire recorders, some as late as 1956, but most failed due to the development of magnetic tape recording. Camras patented an oxide coating for 8mm and 16mm film in 1946. Armour claimed to own the patent to oxide-coated magnetic tape, and Camras would be inducted into the National Inventor's Hall of Fame in 1984. However, courts ruled in 1960 that the patent was invalid. The German telegraphone with its plastic tape developed in the 1930s became the model for American tape recorders after 1947.
Sources:
Morton, David Lindsay, Jr. "The History of Magnetic Recording in the United States, 1888-1978." Ph.D. thesis, Georgia Institute of Technology, 1995, p. 340-379.
Miller, John Anderson. Men and Volts at War: The Story of General Electric in World War II. New York: McGraw Hill, 1947.
"Magnetic Wire Recorder," Life 15, 1942, pp. 49-50.
Grahme, Arthur. "Recording the Saipan Fight on Wire," Popular Science 145, December, 1944, p. 201.
Marvin Camras from Galvin Library, Illinois Institute of Technology