▼ Menu

85A2

Sensibly equivalent to:
0G3 CV449 CV4048 QS1209 QS83/3
See also:
SQ Voltage reference tubes - Mufax Chart Recorder Maintenance Manual
    
Extras ▼

 

The Valvo 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.
The envelope is also marked with 0G3 indicating direct equivalence.
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.
The reverse is plain. The red tinge on the right is a hand that failed to move.
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
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated May 03, 2016.
shape:thin.glass.tube construction:all.glass type:voltage.stabiliser age:1950.1960 base:b7g pins:7 pin:1.a pin:2.k pin:3.ic pin:4.k pin:5.a pin:6.ic pin:7.k
Return to Main Index