The 30PL13 triode beam tetrode was designed specifically for service in a frame output stage of a television receiver. Here we have a Mullard made valve that places the 30PL13 above the Mullard code of PCL800.
The requirements are low power and low frequency service. As with nearly all later television valves the heater is designed for 300 mA and operation as part of a chain across the mains supply.
The small triode with flat cathode and copper supports for the control grid.
The relative size of the two units. The triode is screened from the pentode and the screen partly wraps around the pentode anode.
The pentode anode.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 69 mm tall.
References: Data-sheet & 1040. Type 30PL13 was first introduced in 1959.