The LEADER Model LAG-55 Audio Generator is a dependable high quality instrument designed as a source for measurements in the frequency range from 20 to 200,000 cps. A very stable Wien bridge oscillator circuit is utilized. The frequency range is covered in four decade bands and indicated on a clear easy-to-read dial. Three different waveforms are available, (1) sine waves of low distortion, (2) clean cut square waves and (3) complex or mixed, which are useful in audio testing, servicing and maintenance. The complex wave is a mixture of the power line and an internal high frequency in a 4:1 ratio, used for the intermodulation, or IM, distortion measurements with the built-in high pass filter and an external scope. A very constant output level is maintained due to the use of a thermistor in the negative feedback circuit. FEATURES A. Sine, square and complex waveforms available for all types of audio testing in laboratories, plants and service shops. B. Stable operation due to the use of printed circuitry. C- IM distortion tests with the internal high pass filter and an external scope. D. Rugged construction suited for plant and field use. E. Minimum pull-in at the line frequency and its harmonics. F. Mounted in a steel cabinet, with an attractive two-tone panel. G. Designed for the maximum ease and troublefree operation.