Klystrons
e2v klystrons are in use worldwide in analogue television transmitters and will fit most transmitter types. The range extends from the older unpulsed narrowband tubes to more efficient pulsed wideband types and the higher efficiency energy saving collector klystrons. Although now replaced in new transmitters by IOTs and their high efficiency versions, ESCIOTs, they are still used globally for spares to keep analogue services running.
More recently Klystrons have been used in high power supplies for Scientific establishments, specificaly in the High Energy Physics arena.