The CV449 is a small, special quality voltage stabiliser. The striking voltage is 115 Volts and the maintaining voltage is 85 Volts. For a tube current variation of 1 mA to 10 mA the voltage regulation is 4 Volts.
This valve would have been used to directly stabilise the voltage for an oscillator or be employed as a voltage reference for a stabilised supply. In the latter case the tube would be operated at constant current.
The KB/QG identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the QG identifies the maker as an English Electric Valve Co. factory.
The English Electric logo and identification.
TheThe other logo and reference code.
The thin glass tube envelope is 18 mm in diameter and excluding the B7G base pins, is 46 mm long.