Sensibly equivalent¶ to:
The VR35 is a British Military valve with a commercial equivalent of the M-OV QP21. The valve is directly heated and for battery HT sets. The pair of pentodes were designed to operate in Class B1 and so draw very little standing current. An important fact when the cost of HT batteries was significant. The screen grid is also common to both valves.
The presence of two distinct assemblies is clear from the picture. Also clearly visible are the filament tensioning springs.
The output power was of the order of 0.5 Watt and the anode to anode load was quoted at 25,000 Ohms.
The classic envelope is 36 mm in diameter, and excluding the B7 base pins, is 93 mm tall.
References: Datasheet & 1043. Type VR35 was first introduced in 1934.
Absolute Maximum Operating Conditions¶
Updated February 19, 2014. shape:classic construction:pinch type:double.pentode age:1930.1940 base:b7 heater:2.0v pins:7 pin:1.g1(1) pin:2.g1(2) pin:3.a(2) pin:4.f.g3 pin:5.f pin:6.g2 pin:7.a(1)