A realistic ID model of a bistable two-variable chemical system with a stable focus (SF) surrounded by a stable limit cycle (SLC) is investigated. Initial excitations of a subinterval of the system can generate two types of wave sources depending on the value of the bifurcation parameter which determines the basin of attraction of SF. For a sufficiently small basin of attraction of SF, an initial local excitation of a finite system generates a finite sequence of traveling impulses. Each subsequent impulse is wider than the previous one, and this is the reason finite sequences of impulses can be observed in finite systems. In infinite systems, an infinite number of impulses is generated. If the basin of attraction of SF is sufficiently large, another type of wave source is induced by the initial excitation. Traveling impulses of excitation have a local minimum between their front and back. The wave source generates an infinite number of impulses both in finite systems and in infinite ones.