The PCL805 triode pentode was designed as a domestic television receiver frame output stage for monochrome sets and on rare occasions (ITT CVC5 chassis) colour sets. As is common with TV valves it is designed to operate at a relatively low voltage and high current. The beam tetrode has a quoted load resistance of 4,000 Ohms.
The literature gives ratings for audio service but the PCL86 was the normal TV audio stage valve.
The diminutive triode next to the power section. Between them is a screen.
The power section.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A pins is 68 mm tall.
References: Data-sheet & 3002. Type PCL805 was first introduced in 1968.