  The Echelle spectrograph operating at Vainu Bappu Telescope (VBT) is a
general purpose instrument designed for high resolution spectroscopy. It is
being considered for precision Doppler measurements without altering the
existing design and basic usage. However, the design level limitations and
environmental perturbations are a major source of instability and systematic
errors. As a result, a small Doppler signal in the stellar spectra is
completely swamped by the large and uncontrolled instrumental drift. In this
paper, we discuss some of the remedial measures we took to improve the radial
velocity performance of the spectrograph. We show that a new auto-guider
assembly has greatly reduced the mechanical jitter of the star image at the
fibre input, making the illumination of the spectrograph slit at the other end
stable. We have also installed an iodine absorption cell to track and eliminate
the instrumental drifts to facilitate precision radial velocity observations.
Furthermore, we have developed a generic algorithm that uses iodine exposures
to extract the stellar radial velocities without the need for the complex
forward modeling. Our algorithm is not accurate to the level of traditional
iodine technique. However it is convenient to use on a low-cost general-purpose
spectrograph targeting a moderate Radial Velocity (RV) precision at a few
10-100~$\textrm{ms}^{-1}$ level. Finally, we have demonstrated the usefulness
of our approach by measuring the RV signal of a well known short-period,
planet-hosting star.
