The STV280/40 is a four in one voltage stabiliser that GEC marketed as the Stabilovolt and has a maximum current draw of 40 mA. Also made was the STV280/80 with higher current rating.
It has four anodes, and thus four outputs with gaps of 70 Volts each. These output voltages are 70, 140, 210 & 280.
The striking voltage is above 420 Volts and the tube current is 5 - 35 mA. The tube voltage regulation is about a couple of Volts for each 70 Volt step.
The outer of the concentric cylinders with springs to hold it against the glass. The three main struts attach to a collar around the pinch stem.
Top view of the closed end.
The base cap has the connection details moulded into the plastic.
The wide glass tube envelope is 46 mm in diameter and, excluding the B5 base pins, is 122 mm tall.
Reference: Data-sheet. Type STV280/40 was first introduced in 1936. See also1936 adverts.
