The 0C3 is a cold cathode voltage stabiliser and is identical to the VR105/30. Here the Type is given as 0C3 and VR-105.
This tube will stabilise the voltage across it to 105 Volts for output currents between 5 mA and 40 mA. To strike the tube the voltage must exceed 135 V.
As with all such stabilisers the voltage will vary slightly with the current drawn. For this stabiliser the figure is 4 Volts across the current range. For making a stabilised power supply the reference tube would be run at as close as possible to a constant current. For general use the circuit designer would try to minimise the variation on load on the stabiliser.
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 cathode cylinder is ribbed to maintain the correct shape.
As with all this type of stabiliser the anode is a rod placed at the centre of the cathode cylinder. The geometry determines the voltage.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 87 mm tall.
References: Data-sheet & 1040. Type 0C3 was first introduced in 1939. See also1939 adverts.
