The Model 41 8A RC Oscillator employs a solid-state Wien bridge which oscillates at 10 Hz - 1 MHz in five ranges. Being incorporated with a thermistor amplitude control circuit, the oscillator provides a sine wave with very minor output voltage variation against switching of the frequency range selector and turning of the frequency dial. Since no output voltage readjustment accompanying frequency range switching is required, the Oscillator is very convenient in actual use. The Oscillator incorporates a square wave generator circuit ( Schmitt circuit ) which provides a square waveform with a fast rise time. The output voltage level is adjustable for a very wide range through combined use of a continuously variable attenuator and a -20 dB stepwise attenuator.