The Mullard PCF86 is a VHF TV frequency changer. 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 pentode on the left is mounted at right angles to the smaller triode.
The end view of the pentode anode with side extensions for additional heat sinking.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Data-sheet, 3002 & 1040. Type PCF86 was first introduced in 1960. See also1960 adverts.