We address the issue of internal modes of a kink of a discrete sine-Gordon
equation. The main point of the present study is to elucidate how the
antisymmetric internal mode frequency dependence enters the quasicontinuum
spectrum of nonlocalized waves. We analyze the internal frequency dependencies
as functions of both the number of cites and discreteness parameter and explain
the origin of spectrum peculiarity which arises after the frequency dependence
of antisymmetric mode returns back to the continuous spectrum at some nonzero
value of the intersite coupling.Comment: 5 pages, 3 figure