SIMBAD references

We present observational radial velocity curves for 12 chromospherically active binary systems and individual measurements for a further 5 systems. These binaries are LX Per, V 471 Tau, EI Eri, OU Gem, GK Hya, TY Pyx, Z Her, MM Her, V772 Her, ER Vul, BD-004234, MY Cyg, AR Lac, KZ And, RT And, SZ Psc and EZ Peg. Six of our target binaries do not agree with published ephemerides or orbital parameters. We also present a rigorous derivation of the resolution limit for binary star cross-correlation radial velocities. Using synthetic spectral data we investigate the errors induced by rotational broadening, signal-to-noise ratio, spectral-type mismatch and luminosity ratio.