This valve is clearly marked CV216 but also carries the commercial QS150/40. CV216 is also the service code for the commercial 0D3 or VR150 or GD150A/S gas discharge voltage stabilisers.
The valve exhibits a near constant voltage across it for currents within the range 5 mA to 40 mA. The regulation is 150 plus or minus 5.5 Volts.
Internally pins 3 and 7 are linked. This shorting link is designed to protect the connected equipment from overload, as when the stabiliser is removed the supplied circuit is disconnected.
The construction is of a central anode within a cylindrical cathode.
The GEC brand label plus the GEC Type code of QS150/40.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 86 mm tall.
Reference: Data-sheet. Type QS150/40 was first introduced in 1954. See also1954 adverts.
