Pictures:

Details:
Metal-ceramic klystron, derived from 6BL6; 1500 to 6000 MHz; can be operated CW, pulsed or FM. Pee-wee 4 pin base; external cavity. Made to Polarad specs under WE patents.
Pin 1 – control electrode, pin 2,4 – heater, pin 3 – cathode; resonator grids to the two rings on the body; reflector to cap.
Filament Vf 6.3 Volts / If: 0.68 Ampere / -: Indirect /
Datasheet:
n/a
Links:
zv1009