The Relative Effects of Deemphasis and Noise Weighting Networks on Stereophonic and Monophonic Signal to Noise Measurements

In making signal to noise ratio measurements for monophonic and stereophonic FM signals, the types of noise weighting circuit and deemphasis circuit used have significant effects on the results. In this paper the relative values of noise power are calculated and presented for several common deemphasis and weighting circuits and various types of noise spectra. With these results it is possible to meaningfully compare results obtained from different measurements and to predict how results will scale from one measurement to another.