The PL801 / 30P12 beam tetrode was designed as a single ended audio amplifier output valve for television receiver use or as a TV frame scan output valve.
To operate successfully on the low anode voltage available in a TV receiver the valve has to operate at higher current to achieve the target output power of around 2 Watts.
The box anode from the side.
Face view of the anode. The control grid has a heat radiating fin at the top connected to both supports.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 66 mm tall.
