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 triode with the anode extended to the side for additional heat-sinking and convenience of stitching the plates together.
The triode on the right with the copper support and winding visible. The pentode has both inner grids wound on copper supports.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 49 mm tall.
References: Data-sheet & 1040 Type PCF80 was first introduced in 1953. See also1953 adverts.