The 85A2 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.

In early 1955 Mullard brought out two special quality versions of this stabiliser. The new designs were designed to operate in the presence of vibration whilst maintaining a long life and were aimed at industrial and military applications. Type M8098 fitted with a B7G base and type M8142 with flying leads for direct soldering into circuit.

The thin glass tube envelope is 17 mm in diameter and excluding the B7G base pins, is 46 mm long.

References: Datasheet Type 85A2 was first introduced^¶ in 1950.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	a	k	ic	k	a	ic	k

 
Absolute Maximum Operating Conditions^¶

Stabiliser	Va
	85

PDF scanned from an original document held by the museum

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