6L6 RCA metal can used/very good 1945 era (72.5ma)
6L6G Hitachi Japan NOS rebranded Perma-Test NOS 1962 (73ma)
6L6G Ken Rad coated glass used/75% 1940's (50ma)
6L6G Sylvania branded Silvertone coated glass used/good 1947 (56ma)
6L6GA National Union used/good/80% 1940's (56.4ma)
6L6GA Sylvania SESCO used/good 1950 in white box (56.5ma)
6L6GA Sylvania used/good 1944 (79ma)
6L6GB GE Black Plate used/good 1957 (59ma)
6L6GB Sylvania Black Plate used/good 1955 faded top getter (57ma)
6L6GB Sylvania Black Plate used/good 1955 faded top getter (65ma) (high Ma and Gm)
6L6GC GE NOS 1964 broken center guide pin (61ma)
6L6GC GE tests like new 1964 broken center guide pin (87.5ma)
6L6GC GE Zenith low hours/like new 1960's in white box (61.5ma)
6L6GC Sylvania clear top NOS 1960's copper grid posts (68ma)
6L6GC Sylvania gray plate used/tests like new 1960's (66ma)
6L6GC Tungsol used/good around 1960 - broken center guide pin (73ma)
7581 Tungsol brown base used/75% 1964 (52.5ma)
7581A GE branded RCA NOS 1974 (59.5ma)
7581A GE branded RCA used/good 1973 (56ma)
7581A GE NOS 1979 (76ma)
