Cotron

Built in the 1970s and used by Yorkshire Television these were acquired by YSTV.

Textbook television design

Their robust metal frame and easy access to circuit boards make them very easy to repair, since all of the circuitry uses discrete components (except for a couple of 7400 series logic gates on the pulse cross circuit, which isn't really needed anyway).

Brought back to life in a blitz by Dominic Plunkett, they still find applications despite being only black and white tubes in NaffoCue.