6CA4 GE branded Tungsol NOS 1960's (54/40 and 54/40)
6CA4 Philco by Sylvania NOS 1960's (52/40 and 52/40)
6CA4 RCA branded Super Airline NOS 1960 era (54/40 and 54/40)
6CA4 Silvertone by Sylvania NOS 1960 era (54/40 and 54/40)
6CA4 Sylvania NOS 1960 era (54/40 and 54/40)
6CA4 Sylvania NOS 1960's (52/40 and 53/40)
6CA4=EZ81 RCA used/good 1962 (53/40 and 53/40)
6CA4=EZ81 Sylvania NOS 1960's (53/40 and 54/40)
6CA4=EZ81 Sylvania used/good 1960's (53/40 and 53/40)
EZ81 Mullard UK branded GE used/good 1965 (56/40 and 56/40)