(!!!) (Recommended Pair) 6BL7GTA GE and GE branded Admiral 1960's (38/40ma and 35/45ma)
(!!!) 6BL7GTA GE branded Marconi NOS 1960 era tilted glass (46/53ma) (High Gm) strong single
(!!) (Best Value Pair) 6BL7GTA GE NOS and like new 1960's same build (41.5/43ma and 44/46ma) (Highest Ma)
(!!) (Recommended Pair) 6BL7GT GE "D" getter NOS 1957 same build (34/36ma and 37/32ma)
(!!) (Recommended Pair) 6BL7GTA RCA NOS and like new 1960's (34/40ma and 38.6/39.8ma)
(!!) 6BL7GTA GE NOS "D" getter 1958 (43ma/53ma)
(!) (Recommended Pair) 6BL7GTA RCA coin-base NOS 1970's (33/35ma and 35/30ma)
(!) (Recommended Pair) 6BL7GTA Sylvania Zenith 1963 and 6BL7GT Sylvania 1960 era NOS (38.5/34ma and 33/37ma)
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)
