The ME1100 is the Mullard version of the X-band reflex klystron. This exhibit was made by philips in Holland. The RF is coupled to waveguide 16 via the 30 mm probe that passes through a hole in a specially designed IO valve holder. SeeCV2792 for details.
The reflector connects to the top cap. Fine tuning is done electrically with course tuning achieved by altering the cavity geometry via the screw attached to bellows at the top of the envelope.
The adjustment to the cavity needs only be very small at these frequencies.
A sectioned view of this type of reflex klystron.
The thin metal tube envelope is 26 mm in diameter, and excluding the IO base pins is 55 mm tall.