(!) 12HG7=12GN7A GE USA NOS (52ma and 56ma)

1 pair) 12HG7=12GN7A GE USA NOS

1 tube) 52ma Gm=30,000 tilted bottom mica

1 tube) 56ma Gm=32,500

Matched on Amplitrex

(12HG7=ruggedized frame-grid version of 12BY7A, uprated to 10 watts)

Pentode