Radial velocity curves of photometric variables. For each variable, the observational data (points) are phased with the corresponding photometric period P_phot taken from Kaluzny et al. (2004). The only exception is NV379, where a period of 0.5P_phot was used for phasing. Smooth curves are sinusoidal fits. Zero points on vertical axes correspond to systemic velocities. The standard error in the velocity measurement, estimated in Sect. 3.1, is 15 km s^-1.