The PCF806 is a triode and frame-grid pentode frequency changer for VHF television receivers up to 220 MHz. The company describes this type as exclusive to them.
The local oscillator is based on the triode and the mixer is the pentode. The heater rating is precise and so can be used both in series or parallel configurations.
Made in England and BVA.
The anode of the pentode with notches in the end wall allows the inner grids to be visible.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 42 mm tall.