This VU111 has the characteristic octagonal box surrounding the Type designation etched into the glass. The base clearly is marked Marconi and the valve was made in Canada. Production in Canada was by the RVC joint venture between GE and Marconi but the valve does not make this clear.
The anode is blackened for better cooling by radiation and the ends are rounded.
This high voltage high power half wave rectifier can deliver 125 Watts. A pair producing 250 Watts could feed a high voltage low current transmitter output stage or RADAR system. Equally this device on its own would supply more than adequate power for a WWII cathode ray tube supply.
The July 1963 date is a later addition and indicates the last time it was tested in the stores.
The ceramic top support with fixings for the filament tension springs.
The three filament top loops are held in the helical springs with hook ends.
The tension spring wire is fed through the ceramic insulator and then spot welded to a small cross bar. Much manual dexterity is required in this.
The ceramic support above the pinch. Inside the anode can be seen the oxide coated filament.
This valve came in an over-sized pasteboard box. The label gives the VU111 and the old stores location of 10E/146. On the label is also the RVC logo that is missing from the valve itself. The box is 130 mm square and 225 tall.
The labels on the box. REME Donnington 1963.
The label on the underside includes the CV1111 designation. Inside the box the valve was wrapped in a sandwich of two layers of paper with fibrous pulp in between.
The classic envelope is 51 mm in diameter and excluding the B4 base pins, is 125 mm tall.