(!!!!!) (Best Overall Pair) 311B Western Electric NOS 1956 and 1964 (35ma and 36ma)
(!!!!!) (Best Overall Pair) 311B Western Electric NOS 1972-1974 (32ma and 33.4ma)
(!!!!!) (Best Overall Pair) 311B Western Electric NOS 1972-1974 (36.2ma and 37.8ma)
(!!!!) (Best Pair) 311B Amperex made in Russia NOS 1977 (34.2ma and 34.5ma) (very good construction)
(!!!!) (Recommended Pair) 311B Western Electric NOS 1973 and 1975 (35.2ma and 36.4ma)
(!!!) (2nd Best Pair) 311B Amperex made in Russia NOS 1977 (31.8ma and 33.2ma) (very good construction)
(!!!) (Best Single) 311B Western Electric NOS 1956 (31.6ma)
(!!!) (Recommended Pair) 311B Amperex made in Russia NOS 1977 (37.2ma and 38.5ma) (Highest mA and Gm)
(!!!) (Recommended Pair) 311B WE used/good 1960-1961 partially faded getters (24.5ma and 26.5ma)
(!!!) 311B Western Electric used/like new condition 1960 (25ma)
(!!) (Good Value Pair) 311B WE used/good, faded getters 1960 and 1967 (28ma and 33ma)
(!!) (Recommended Single) 311B Western Electric NOS 1967 glass slightly tilted, large getter, in white box (33ma)
311B Western Electric used/strong, faded getter 1964 (35.5ma)
