This 1939 tube circuit uses two tubes to amplify voltages at scales selected by the resistive network. The circuit includes the source which is a double diode of the time. The power supply uses a transformer and a 5W resistive regulator.

This 1939 tube circuit uses two tubes to amplify voltages at scales selected by the resistive network. The circuit includes the source which is a double diode of the time. The power supply uses a transformer and a 5W resistive regulator.