374A Western Electric black plate used/good 1960's (18-21ma)

1) 18ma Gm=3000 1965 -

1) 20.4ma Gm=3200 1967 -

1) 18.2ma Gm=3300 1967 -

1) 20ma Gm=3400 1967 small crack in base -

1) 18.2ma Gm=2900 1967 -

1) 19.4ma Gm=3400 1967 -

1) 20.4ma Gm=3300 1967 -

1) 19.2ma Gm=3200 1966 -

1) 20.2ma Gm=3000 1967-

1) 19.2ma Gm=3000 1967 -

MAKE TUBE SELECTION AT CHECKOUT 

Tested on Amplitrex

Vplate=135V

Vscreen=135V

Vgrid=-18V

Good used Ma range = 18-21ma

Good used Gm range = 2800-3000

(374A specs: Vfil=3V @ 530ma, Vplate=135V, Iplate=18ma, Mu=210, Gm=3000, Rp=70K ohms, Pout=1.3 watts)