The CV539 is a TR switch for use in a separate cavity. The prototype was the 1B23. The nominal operating frequency was 0.945 GHz. The gas filling is low pressure hydrogen.
The /RB identifies the maker as Ferranti, Dundee.
The serial number and the maker code.
The pinch and lower electrode. The upper electrode is set a small distance from the disc electrode.
One can just make out the gap between the centre electrode and the disc electrode.
The main discharge gap.
The thin glass envelope is 19 mm in diameter and, excluding the base pins, is 69 mm tall.
