The 403B is a sharp cutoff pentode which came out in 1948. 6.3 volt @ 150 ma filament, plate 150 volts @ 6.6 ma, Gm 4500,
Production was 31,000 in 1979. Discontinued 1984.
Norm
: does anyone know what a w.e. 403-b mini tube is for? I cant find any info on it.