The CV188 voltage stabiliser was designed for accurate regulation. It has a B4 base but the envelope is small and compact. The striking voltage is 140, and once ionisation has occurred the tube can regulate the 100 Volt output to 2 Volts for currents of between 1 and 8 mA.
This high stability low current device would be useful for stabilising supplies to oscillators or as a reference voltage in regulated power supplies.
The anode is a disc with the edges turned down. The cathode rises through the disc and is formed by a small sheet folded at right angles and angled towards the anode.
The orange neon glow forms across the surface of the anode disc when in use.
The wide glass tube envelope is 29 mm in diameter and, excluding the B4 base pins, is 63 mm tall.