  Since early 2015 a new radial velocity monitoring campaign is going on at the
University Observatory Jena. The aim of this project is to obtain current
radial velocity measurements of selected single-lined spectroscopic binary
systems, to redetermine and/or constrain their orbital solutions. In this paper
we characterize the properties of the target sample of the project, describe
the spectroscopic observations, the data-reduction and analysis and present the
first results of the project, taken with the fiber-linked astronomical
spectrograph FLECHAS. We present 391 radial velocity measurements of eight
spectroscopic binaries, which were taken within an epoch difference of 1.6
years. These radial velocities were used to determine the spectroscopic orbital
elements of the observed binary systems, which exhibit orbital periods in the
range between nearly one up to several dozens of days. We could constrain the
orbital solutions of seven of these binary systems, and redetermine the orbital
solution of phi Dra, whose orbit exhibits >4 times longer orbital period and is
more eccentric than given in the 9th Catalogue of Spectroscopic Binary Orbits.
