Intermodulation distoration meter employing the hall effect

This paper presents a method of measuring intermodulation distortion produced by a nonlinear system operating in the audio-frequency spectrum. The design of the measuring device is based upon the Hall principle. Transistorized circuitry is used throughout. Both the circuitry employed and the theory of operation are discussed. The instrument is simple to operate and permits the measurement of intermodulation distortion at any frequency on a point-by-point basis within the range of 400 to 20,000 cps. Distortion measurements may be made in two ranges; zero to one per cent and zero to five per cent.