The Pen46 is an early television line output pentode valve. In line scan duty high surge voltages appear, this valve can withstand an anode surge of 3,000 Volts.
The Pen46 was used in the 1948 Murphy television receiver V114 as the line output valve.
The box anode is open at the sides, and the two wire grids are visible.
A closer view: the grid wires pass flat across the cathode. The bright beam plates are seen inside the dark anode.
The control grid has heat radiating fins on the top of the upper supports.
Top view showing the shape of the control grid radiator. The anode connection to the top cap is on the right.
On the right is the thick bridge wire connecting the beam plates together and the centre lead connects to the cathode.
The classic envelope is 54 mm in diameter and, excluding the MO base pins, is 110 mm tall.
References: Data-sheet, Data, 1040 & 1043. Type Pen46 was first introduced in 1940. See also1940 adverts.
