The research of influence of periodical signal discontinuity on spectrum form is considered in the article. The numerical modeling of the system of discontinuous signals is performed. The spectrum of the system built from time discreet sampling is analyzed. The plots of the sample correlation coefficient between spectrums of continuous and discontinues signals are shown in the article. The research is needed for the development of digital measuring system for quartz plates frequency detecting.

Keywords: amplitude signal spectrum, discontinuous signal, quartz plates