Unified analysis of tracing and tracking error

Tracing and tracking errors in phonograph reproduction are shown to have a common basis of analysis, the skew transformation, and the distortion arising from these errors to be due solely to phase perturbation. The phase-perturbation model is used to show the principles by which compensating schemes must be governed. Formulas are given for the distortion arising from the joint application of tracing and tracking error, and the recording-velocity restrictions so implied are plotted. In the Appendix, a means for obtaining exact closed-form Fourier analyses is explained and results quoted.