1 matched pair) 6F6G Marconi Spain NOS 1949

1 tube) 31.6ma Gm=2450 taller bottle - dark gray phosphor coating

1 tube) 32.0ma Gm=2620 - light gray phosphor coating

Test settings:

Vplate=285V

Vscreen=285V

Vgrid=-20V

Good Ma range = 32-38ma

Good Gm range = 2400-2600

Recommended for

- Sparton Nocturne 1186 from 1936
- Fire Stone Sir Chef S-7404-3 1939
- Montgomery-Ward Airline Model 62-226
- Supratek Cortese
- Victoria
- WE 106 preamp clone

- Wards Airline Radio