The solid-state 652A Test Oscillator simplifies frequency response determination by providing a constant amplitude reference voltage of adjustable frequency. Frequency response of voltmeters, oscilloscopes, video amplifiers and filters from 10Hz to 10MHz (6 bands, dial calibration: 1 to 10) can be measured quickly and accurately. Output amplitude: 3.16 V maximum into 50-ohms or 600-ohms. This unit provides an output monitor which keeps amplitude flat within 0.25% across the band.