(!!) (~ Best Value Pair ~) 56 Sylvania test like new 1940”s (5.3ma and 5.5ma)

1 pair) 56 Sylvania test like new 1940”s same build in white boxes

1 tube) 5.5ma Gm=1500 Sylvania rebranded Philco

1 tube) 5.3ma Gm=1400 Sylvania lightning logo 1946 a little less carbon on top and bottom of plate

Matched on Amplitrex:

Vplate=250V

Vgrid=-13.5V

Iplate good range = 4.5-5.5ma

Gm=1400