This high voltage high power half wave rectifier can deliver 125 watts. A pair producing 250 Watts could feed a high voltage radar pulse modulator HT supply. The PIV for this valve is 14 kV.
The anode connects to the top cap and at the base is held rigid in glass rods fused into the pinch.
The anode with side strips to increase the radiating surface area and to connect to the top cap.
The working face of the box anode.
A close-up of the electrodes. The filament is an oxide coated ribbon held at the top by three retaining springs to maintain tension as the ribbon expands when hot.
The classic envelope is 50 mm in diameter and excluding the B4 base pins, is 125 mm tall.