The PCL86 was designed for the audio stage of a television receiver and offered a quality output. The Thorn industries group included TV manufacture and retail sales and rentals. It is probable that this valve was made for the service devision of the rental company.
The PCL86 as a single ended audio amplifier would have a cathode resistor of 125 Ω and an anode load of 5,100 Ω and under these conditions would produce an output power of 4.1 Watts at a distortion of 10%.
The high gain triode on the left.
The end view of the output valve anode shows the bright beam plate within.
A British made valve.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 69 mm tall.
References: Data-sheet & 1040. Type PCL86 was first introduced in 1961.