I. Introduction
In information-measuring systems for various purposes, tracking meters have been widely used. At the same time, they are often designed to measure non-energy parameters of a useful signal, for example, frequency, initial phase, etc. In publications [1–7, etc.] the study of some features of their work is given. The authors in publication [8] showed how the determination of the spectral density (SD) of the mismatch signal of the discriminator, as well as the steepness of the discriminatory characteristic (DC) of the latter, makes it possible to obtain an estimate of the measurement accuracy of one information parameter of the signal. At the same time, both multiplicative (MN) and additive (AN) noises acted on the signal at the same time [9–15, etc.]. In addition, the above-mentioned publication provides a generalized structure diagram of a tracking meter, as well as a functional diagram of a two-channel discriminator, the latter being intended to be used in the present work.