A harmonic distortion standard

All harmonic distortion analyzer instruments may not give the same reading when measuring a particular audio range signal. A design method is presented that can supply a signal with a precisely determined amount of harmonic distortion. Digital signal generation technique is used. Factors which determine the accuracy of the signal are examined. An instrument was designed using the outlined principles. With it, the operator can control the frequency of operation, the harmonic, and the percentage of distortion. Results from the sample constructed are presented. Performance of a number of distortion analyzers are shown.