The 0C3 is a cold cathode voltage stabiliser and is identical to the VR105/30. The basic operation conditions are contained in the 105/30 of the alternate type code. 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.

The 0C3 is an American product and the anchor motif suggests that this was originally supplied to the US Navy.

The classic envelope is 36 mm in diameter and, excluding the IO base pins, is 87 mm tall.

References: Datasheet & ¹⁰⁴⁰. Type 0C3 was first introduced^¶ in 1939.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	-	k	ic	-	a	-	ic	-

 
Absolute Maximum Operating Conditions^¶

Stabiliser	Va	mAa
	105	40

Thanks to Frank Philipse for supplying the above PDF datasheet