(!!!) (BEST SINGLE) GL-800=VT-64 GE gray plate NOS 1948 (57ma and Gm=2500) (not a pair)
(!!) (#1 800 black plate single) 800=VT-64 RCA black plate like new 1940's (52ma, Gm=2430) (tested on Amplitrex)
(!!) (#2 800 gray plate) 800=VT-64 RCA gray plate NOS late 1940's (47.5ma, Gm=2150) (tested on Amplitrex)
800=VT-64 RCA DeForest black plate engraved base used/good 1930's (38ma, Gm=1750) (tested on Amplitrex)
800=VT-64 RCA Lab Development tube charcoal black plate used/good 1940 era (42ma, Gm=2150)
800=VT-64 RCA Radiotron charcoal black plate engraved base used 1930's (42ma, Gm=2000)
