Soon after his experimental Washington station signed on , DuMont began experimental coaxial cable hookups between his laboratories in Passaic , New Jersey , and his two stations . It is said that one of those broadcasts on the hookup announced that the U.S. had dropped an atomic bomb on Nagasaki , 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 was joined in 1949 by WDTV ( channel 3 ) in Pittsburgh .