56 RCA Balloon engraved base black plate tests like new 1930's (4.7ma)
56 RCA no name NOS 1940's getter halo screen loose at bottom of tube (6.5ma)
56 RCA no name NOS 1940's made for Radiotelefonica Argentia (5.1ma)
56 RCA used/good 1940's (4.7ma)
56 RCA used/good 1940's plate slightly tilted (4.9ma)
56 Super Airline used/good 1940's (4.1ma)
56 Sylvania branded RCA NOS 1946 (6.0ma)
56 Sylvania NOS 1940's (5.8ma)
56 Tungsol rebranded Raytheon tests like new 1940's (6.1ma)
56 Ultron UK used/good 1952 (4.5ma)
721A Sylvania NOS 1943 (1 in stock)
