56 National Union used/good 1950 small faded getter (4.1ma)
56 no name NOS 1950's (5.7ma)
56 Philco by Sylvania used/good 1940's (5.2ma)
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)
6973 RCA black plate used/good 1950's (34ma)
6973 RCA gray plate used/good 1970 era (56.5ma)
6AU5GT used/good
6BH6 RCA black plate NOS "D" getter halo 1949 (7.8ma)
6BH6 RCA black plate NOS "D" getter halo 1951 (5.1ma)
6BH6 RCA black plate NOS "D" getter halo 1961 (6.3ma)
6BQ5 RCA gray plate used/good 1967 (32.6ma)
