Cathodeon Ltd. was established in 1935 as a subsidiary of Pye Limited, formed from the vacuum physics laboratory of the former Pye Radio Limited. They largely focused on the manufacture of thermionic valves, cathode ray tubes and glass/metal seals and were based at Nuffield Road, Cambridge.

In 1954, Pye Limited created another subsidiary, Cathodeon Electronic, to take over the production of the cathode ray tubes which had 300 employees by 1961. This allowed Cathodeon Ltd. to pursue the production of their successful range of lamps for use in laboratory analytical instrumentation.

In 1968, the company was integrated into the new Pye Unicam, and then in 1981, they became part of Cambridge Electronic Industries.