RCA TT-5 1939 (U.S.A.) The TT-5 is RCA's first tabletop electronic television. This $199.50 set provided vision only and hence was the most inexpensive of the RCA line. It was the set that the average family might afford. To amplify the audio signal, a wire was connected to a radio with a television sound input. From 1937 to 1940, RCA and GE included labelled television sound input plugs in many of their radios in preparation for marketing vision-only tv sets. See the TT-5 in historical context