  The theory of perturbations of spherically symmetric self-similar black holes
is presented, in the Newman-Penrose formalism. It is shown that the wave
equations for gravitational, electromagnetic, and scalar waves are separable,
though not decoupled. A generalization of the Teukolsky equation is given.
Monopole and dipole modes are treated. The Newman-Penrose wave equations
governing polar and axial spin-0 perturbations are explored.
