On This Day in Telephone History August 6TH 1940 W.H. Doherty of Bell Telephone Laboratories was granted U.S. Patent 2,210,028 on a high efficiency amplifier for radio transmission which speedily came into wide use.
On This Day in Telephone History August 6TH 1940 W.H. Doherty of Bell Telephone Laboratories was granted U.S. Patent 2,210,028 on a high efficiency amplifier for radio transmission which speedily came into wide use.