The CV6142 (commercially the K391A) is a small reflex klystron oscillator with integral waveguide 16 flange. The operating frequency is 8.8 GHz to 8.885 GHz and the output is 60 mW - sufficient for a local oscillator or small transmitter. The main tuning is mechanical via the screw but electrically the operating frequency can be varied over a 40 MHz range. This electrical tuning can also be used to apply modulation as wideband FM.
The reflector voltage is given on the label as -58 Volts.
The KB/Q identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the Q identifies the maker as English Electric Valve Co., Chelmsford.
The tuning screw and EE logo.
The WG16 flange with matching made by the reduced aperture and adjustment screw.
The integral leads suggest that operation could be in a humid atmosphere - aircraft?
The thin metal tube envelope is 16 mm in diameter, and excluding the wires is 58 mm tall.
