The Mullard PCF86 is a miniature VHF TV frequency changer and was made in the UK. It has been designed for the triode oscillator to supply 3.2 Volts peak to peak to the pentode mixer section. The PCF806 is an improved form of the PCF86.
The frame grid pentode is on the left with the triode on the right.
The copper strut from pin 9 connects to the screen grid above the top mica. The coiled heater can be seen above the base.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 47 mm tall.
References: Datasheet, 3002 & 1040. Type PCF86 was first introduced in 1960.