The Model 205 AG Audio Signal Generator contains all the necessary instruments for accurate gain or frequency response measurements. The basic audio oscillator uses a Wein Bridge circuit to generate a sine wave. This. sine wave is then amplified and provided at the OUTPUT terminals. Any desired frequency in the range of 20 Hz to 20 kHz is obtainable from the instrument. Two voltmeters are pro­vided on the front panel. One voltmeter measures input to the device under test, the second measures output from the device under test. An attenuator is provided to set the output voltage to the desired level. Output impedance can be changed by means of selector switch to 50,200,600, or 5000 ohms.