Radiotechnique 85A1
The 85A1 voltage stabilizer will strike at 125 volts and is useful for output currents of between 1 - 8 mA. As a reference tube, the optimum operating point is with the discharge running at 4.5 mA.
The wide glass tube envelope is 27 mm in diameter and, excluding the B8B base pins, is 60 mm tall.
The 85A1 was first introduced in 1948.