Fundamental and 3rd harmonic АС magnetic susceptibility of over-doped polycrystalline Y1−xCaxBa2Cu3O7−δ (x = 0.025 and x = 0.20) samples

► ACMS harmonic study of samples with S-I-S and S-N-S inter-grain links. ► The sample with S-N-S inter-grain links is more stable in magnetic field. ► The influence of the dynamical regimes is more pronounced in sample with S-I-S links. ► Comparison of the results to the existing theoretical models of AC magnetic response. ► Grain surface eddy currents of Y(Ca0.20)BaCuO cause χ1″ (T) and χ3″ (T) shifting.