(!!) (Recommended Pair) 6CB5A Sylvania branded Dumont NOS 1960”s (58ma and 60ma)

1 pair) 6CB5A Sylvania NOS 1960”s same build

1 tube) 58ma Gm=6700 Sylvania

1 tube) 60ma Gm=6700 Sylvania branded Dumont

Tested on Amplitrex

Vplate=175

Vscreen=175

Vgrid=-30

Iplate = 70-100ma (Good)

Gm = 7,500 – 9,000 (Good)