The 4B31 is a half wave power rectifier with a maximum PIV of 16 kV and a maximum current of 12 A as a clipper diode or 470 mA as a rectifier.
The base has ceramic insulation between the pins and inside the envelope the insulation is also ceramic. The anode connects to the top cap and is pressed from two pieces of sheet that have subsequently been coated. The anode cavity is 9 mm x 46 mm and has rounded ends, the flat side fins are the fixing points. Within the anode cavity are two separate oxide covered cathodes.
The wide glass tube envelope is 60 mm in diameter and, excluding the four base pins, is 150 mm tall.
Absolute Maximum Operating Conditions¶
Updated February 21, 2014. shape:wide.glass.tube construction:glass.foot type:rectifier.hw age:1950.1960 base: heater:5.0v pins:4 pin:1.2 pin:2.h.k pin:3.h pin:4.3 pin:tc.a