  In this work we analyze the behaviour of the excess Ca~{\sc ii} H \& K and
H$\epsilon$ emissions in a sample of 73 chromospherically active binary systems
(RS$~$CVn and BY$~$Dra classes), of different activity levels and luminosity
classes. This sample includes the 53 stars analyzed by Fern\'andez-Figueroa et
al. (1994) and the observations of 28 systems described by Montes et al.
(1995c). By using the spectral subtraction technique (subtraction of a
synthesized stellar spectrum constructed from reference stars of spectral type
and luminosity class similar to those of the binary star components) we obtain
the active-chromosphere contribution to the Ca~{\sc ii} H \& K lines in these
73 systems. We have determined the excess Ca~{\sc ii} H \& K emission
equivalent widths and converted them into surface fluxes. The emissions arising
from each component were obtained when it was possible to deblend both
contributions. We have found that the components of active binaries are
generally stronger emitters than single active stars for a given effective
temperature and rotation rate. A slight decline of the excess Ca~{\sc ii} H \&
K emissions towards longer rotation periods, P$_{\rm rot}$, and larger Rossby
numbers, R$_{0}$, is found. When we use R$_{0}$ instead of P$_{\rm rot}$ the
scatter is reduced and a saturation at R$_{0}$ $\approx$~0.3 is observed. A
good correlation between the excess Ca~{\sc ii}~K and H$\epsilon$ chromospheric
emission fluxes has been found. The correlations obtained between the excess
Ca~{\sc ii}~K emission and other activity indicators, (C~{\sc iv} in the
transition region, and X-rays in the corona) indicate that the exponents of the
power-law relations increase with the formation temperature of the spectral
features.
