  The Hyades constitute a homogeneous sample of stars ideal for investigating
the dependence of planet formation on the mass of the central star. Due to
their youth, Hyades members are much more chromospherically active than stars
traditionally surveyed for planets using high precision radial velocity (RV)
techniques. Therefore, we have conducted a detailed investigation of whether
magnetic activity of our Hyades target stars will interfere with our ability to
make precise RV searches for substellar companions. We measure chromospheric
activity (which we take as a proxy for magnetic activity) by computing the
equivalent of the R'HK activity index from the Ca II K line. <R'HK> is not
constant in the Hyades: we confirm that it decreases with increasing
temperature in the F stars, and also find it decreases for stars cooler than
mid-K. We examine correlations between simultaneously measured R'HK and RV
using both a classical statistical test and a Bayesian odds ratio test. We find
that there is a significant correlation between R'HK and the RV in only 5 of
the 82 stars in this sample. Thus, simple Rprime HK-RV correlations will
generally not be effective in correcting the measured RV values for the effects
of magnetic activity in the Hyades. We argue that this implies long timescale
activity variations (of order a few years; i.e., magnetic cycles or growth and
decay of plage regions) will not significantly hinder our search for planets in
the Hyades if the stars are closely monitored for chromospheric activity. The
trends in the RV scatter (sigma'_v) with <R'HK>, vsini, and P_rot for our stars
is generally consistent with those found in field stars in the Lick planet
search data, with the notable exception of a shallower dependence of sigma'_v
on <R'HK> for F stars.
