 Soon after his experimental Washington station signed on , DuMont began experimental coaxial cable <unk> between his laboratories in <unk> , New Jersey , and his two stations . It is said that one of those broadcasts on the <unk> announced that the U.S. had dropped an atomic bomb on <unk> , Japan , on August 9 , 1945 . This was later considered to be the official beginning of the DuMont Network by both Thomas T. Goldsmith , the network 's chief engineer and DuMont 's best friend , and DuMont himself . Regular network service began on August 15 , 1946 , on WABD and W3XWT . In 1947 , W3XWT became WTTG , named after Goldsmith . The pair were joined in 1949 by WDTV ( channel 3 ) in Pittsburgh . 
