  Motivated by the recent discovery of an Halpha emission line component
originating close to the white dwarf primary in the post-common-envelope binary
(PCEB) LTT 560, we have undertaken a spectroscopic snapshot survey on 11
short-period (P_orb < 6 h) PCEBs using FORS2. We have found multi-component
Halpha emission line profiles in six of our targets, indicating that multiple
Halpha emission sites are rather common in short-period PCEBs. The underlying
physical mechanisms, however, can be fundamentally different. In our sample we
find one system where the extracted radial velocities of two identified
components indicate that both originate in the late-type secondary star, where
one is caused by irradiation from the hot white dwarf primary and the other by
stellar activity. Another object presents two components that are located on
opposite sides of the centre-of-mass, suggesting a case similar to LTT 560,
i.e. that accretion of stellar wind from the secondary star produces Halpha
emission on, or close to, the white dwarf.
