Solid solution samples of the three-component system (1 − $x$)Pb(Ti${}_{0.5}$Zr${}_{0.5}$)O${}_3-x$CdNb₂O₆ with $x$ = 0.0125–0.0500, $\mathrm{\Delta }$$x$ = 0.0125 were obtained by solid phase synthesis followed by sintering using conventional ceramic technology. The crystal structure, microstructure, electrophysical, and thermophysical properties of these ceramics have been studied. It is shown that all studied solid solutions can be divided into two groups (with $x$ = 0.0125 and with $x>$ 0.0125), characterized by different characteristics of the change in properties with variations in external influences. This is probably due to the transition from a perovskite-type structure with a tetragonal (T) unit cell to inhomogeneous solid solutions consisting of a series of T-phases with similar cell parameters. A conclusion is made about the expediency of using the data obtained in the development of similar materials for devices based on them.Solid solution samples of the three-component system (1 − $x$)Pb(Ti${}_{0.5}$Zr${}_{0.5}$)O${}_3-x$CdNb₂O₆ with $x$ = 0.0125–0.0500, $\mathrm{\Delta }$$x$ = 0.0125 were obtained by solid phase synthesis followed by sintering using conventional ceramic technology. The crystal structure, microstructure, electrophysical, and thermophysical properties of these ceramics have been studied. It is shown that all studied solid solutions can be divided into two groups (with $x$ = 0.0125 and with $x>$ 0.0125), characterized by different characteristics of the change in properties with variations in external influences. This is probably due to the transition from a perovskite-type structure with a tetragonal (T) unit cell to inhomogeneous solid solutions consisting of a series of T-phases with similar cell parameters. A conclusion is made about the expediency of using the data obtained in the development of similar materials for devices based on them.