The NS1is a pre-WWII multi voltage stabiliser designed for the UK Navy. The specification was based on the STC 280/80 and later the valve became known as the CV1069 - also printed on the glass.
The striking voltage is 363 V, and four gaps exist within the bell cathode. The regulated voltages start high at 280 Volts and the other gaps drop the voltage to 205, 143 and finally 73 Volts. The tube current is 10 - 70 mA, and the regulation is 4 Volts per gap, or 1.4%.
The insulated connections entering the lower mica.
The top of the closed outer cylinder held in the glass envelope by the side mica pieces.
The balloon envelope is 61 mm in diameter and, excluding the B5 base pins, is 122 mm tall.
