Socket / Chimney Combination has been removed from equipment. The 4X250F Tubes have 26.5v filaments and are Eimac NOS.
Assembly includes (2) - Eimac 4X250F tested/unused (NOS) tubes and 2 - Eimac SK650 sockets with chimneys mounted on a sub-chassis. This socket was removed from military equipment that used the 4X150D.
The socket assembly will work with 4X150 to 4X350 series as well as 4CX250 & 4CX350 series tubes. The 4X250F is similar to the 4X250B but with 26.5v filament. The 4X250F is an early Eimac glass version tube.
NOTE: Will require addition of screen bypass capacitors.