(!) 448A Western Electric smooth top used/good 1971 (1 pair: 28ma and 29.4ma) (Matched on Amplitrex)

1 pair) 448A Western Electric smooth top “”D”” getter halos used/good – reboxed

1 tube) 28.0ma Gm=24,000 faded top getter

1 tube) 29.4ma Gm=24,200 good top getter

Amplitrex Test Data:

Vplate=135V

Vscreen=135V

Vgrid=-2

Good Ma range 20-30ma

Good Gm = 23,000 – 27,000

DIY pentode