Sensibly equivalent¶ to:
The QP230 is a directly heated double pentode for audio output use. It was designed to operate from an accumulator filament supply and a 120 Volt HT battery. The two pentodes being designed to operate as a quiescent push pull output stage in class B1 with a drive of 19 Volts pk-pk across the grids.
The top of the dome is the site of the printed lettering. Also visible is the mica support for the electrodes.
The classic envelope is 39 mm in diameter and, excluding the B7 base pins, is 91 mm tall.
References: Data-sheet & 1043. Type QP230 was first introduced in 1936.
Absolute Maximum Operating Conditions¶
Updated December13, 2012. shape:classic construction:pinch type:double.pentode age:1930.1940 base:b7 heater:2.0v pins:7 pin:1.g1 pin:2.g1 pin:3.a pin:4.f pin:5.f pin:6.g2 pin:7.a