The Calibration of Amplitude Modulation Meters with a Heterodyne Signal

Errors which may occur in the calibration of peak or average reading amplitude modulation meters with a heterodyne signal are investigated in detail. Relations between the heterodyne-amplitude ratio M and the true modulation factor m of a sinusoidally modulated wave are derived. Using these results, heterodyne calibration of modulation analyzers to read m exactly can readily be carried out.