  We monitored a set of emission lines in the optical spectra of CH Cyg using
the 1.5-m telescope at the Tartu Observatory, Estonia. Most of the spectra were
registered in the H alpha region, but other Balmer lines and lines of He, N, O,
and Fe were also investigated in terms of their equivalent widths, radial
velocities, and absolute fluxes. The spectra indicate different stages that CH
Cyg has been through in the course of our observations. During quiescence, the
strength of the line profiles changes in opposite phase with the star's
luminosity. The H alpha profile becomes double-peaked at times, which may point
to the temporary presence of some disk-like structure, but also to absorption
in neutral gas surrounding the area of the formation of the emission component.
In 1999, when a periastron passage is assumed according to the 5700-day model,
the Balmer lines strengthen considerably, as might be expected due to an
increase in the accretion rate. The eclipse in 2001, however, is not noticed.
At certain episodes, the controversial 756-day period of CH Cyg is seen in our
data.
