6AX4GTB RCA NOS 1968 (54/20)
6AX4GTB RCA used/tests like new 1964 (57/40)
6AX4GTB Rogers Canada NOS 1960's (52/20)
6AX4GTB Sylvania coin-base NOS 1970's (54/20)
6AX4GTB Sylvania used/good (52/40)
6B4G Raytheon NOS 1950 era (94ma)
6B4G Raytheon NOS separate plates 1940's (100ma)
6B4G Sylvania rebranded Delco NOS separate plates 1952 (81ma)
6B4G Sylvania rebranded RCA used/good 1953 (77.5ma)
6B4G Zenith by Sylvania NOS plates connected 1940's (123ma)
6BG6GA GE Relaible Selectron NOS 1957 (74ma)
6BG6GA Raytheon NOS 1957 (73ma)
6BJ6 Sylvania NOS 1957 (8.6mA)
6BL7GT Sylvania low hours 1953 D = rectangle getter halo long scratch on base (33.5/37.5ma)
6BL7GTA GE gray plates NOS 1974 (47/53ma)
6BL7GTA RCA NOS 1968 (32/33.5ma)
6BL7GTA Sylvania used/good 1960's (31/33ma)
6BL7GTA Sylvania Zenith NOS 1963 (38.5/34ma)
6C4WA Sylvania NOS 1965 and 1971 (read review)
6C6 Sylvania NOS 1950 (48/31)
