The PCF802 was designed as the first stages in television line frequency generation prior to the line output stage. The pentode is described by Mullard as the oscillator while the triode is for service as a reactance valve. This suggests the triode acting as a frequency controlling stage.
This exhibit was made in Great Britain and features the older style Mullard logo.
The pentode on the left with the smaller triode on the right separated from the pentode by the central electrostatic screen.
The triode is mounted at right angles to the pentode axis. The control grid is wound on copper supports but does not need cooling fins.
Looking along the grid axis of the pentode section. The spacing of the suppressor grid turns can be seen.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Datasheet, 3002 & 1040. Type PCF802 was first introduced in 1962.