The PCL805 triode pentode was purpose 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 audio stage valve.
On the picture it can be seen that the triode is a completely separate electrode structure with an electrostatic screen between it and the power valve electrodes.
The Peco logo.
The small triode with copper grid supports, with the bright screen behind and the pentode at the back.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A pins is 68 mm tall.
References: Datasheet. Type PCL805 was first introduced in 1968.