The PCF806 is a triode plus frame-grid pentode. Design use is as a frequency changer for VHF television receivers and for other applications at frequencies up to 220 MHz. The local oscillator is based on the triode and the mixer is the pentode.
The pentode on the left, screen in the centre and triode on the right. The top mica is a double sheet.
The triode with the screen behind.
The end wall of the pentode anode showing the support for the suppressor grid within. The triode is mounted at right angles to the grid axis of the pentode.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 49 mm tall.