1 matched pair) 6F6G Marconi Spain NOS 1949

1 tube) 43.6ma Gm=2900 - slightly taller bottle 

1 tube) 44.0ma Gm=2860 

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