The PCF80 is from the dawn of the era of VHF Band III television in the UK. The valve is a triode pentode, with separate cathodes, designed to function as a mixer and oscillator in the tuner front end.
The envelope has Made in England and the BVA initials. The triode grid supports appear above the top mica.
The triode is on the right of the image. the screening above the pentode can be seen as bright metal.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Data-sheet & 1040 Type PCF80 was first introduced in 1953. See also1953 adverts.
