(!) 448A Western Electric smooth top used/good “”D”” getter halo 1963-1970 (1 pair: 35ma and 36.5ma) (Matched on Amplitrex)

1 pair) 448A Western Electric smooth top used/good 1963-1970 – reboxed

1 tube) 35.0ma Gm=26,000

1 tube) 36.5ma Gm=28,700

Amplitrex Test Data:

Vplate=135V

Vscreen=135V

Vgrid=-2

Good Ma range 20-30ma

Good Gm = 23,000 – 27,000

DIY pentode