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 has the flange seam along the centre of the working face for best heat transfer. The control grid has a radiating fin at the top. The beam plates are fixed through the mica discs with tabs.
This angled view shows that the ends of the anode are largely open.
Looking through the open end of the anode the inner grids and beam plates can easily be seen. The grids have different pitches but both pass flat across the cathode.
The classic envelope is 54 mm in diameter and, excluding the MO base pins, is 112 mm tall.
References: Data-sheet, Data, 1040 & 1043. Type Pen46 was first introduced in 1940. See also1940 adverts.
