(!!!) (Best Pair #4) 448A Western Electric tipped top used/tests like new 1965 (26.4ma and 26.8ma)

1 pair) 448A Western Electric “”tipped top”” used/tests like new D getter halo 1965 in white boxes

1 tube) 26.4ma Gm=26,900

1 tube) 26.8ma Gm=25,500

Amplitrex Test Data:

Vplate=135V

Vscreen=135V

Vgrid=-2.5V

Good Ma range 18-25ma

Good Gm = 25,000

DIY pentode