  Spectropolarimetric data allow for simultaneous monitoring of stellar
chromospheric $\log{R^{\prime}_{\rm{HK}}}$ activity and the surface-averaged
longitudinal magnetic field, $B_l$, giving the opportunity to probe the
relationship between large-scale stellar magnetic fields and chromospheric
manifestations of magnetism. We present $\log{R^{\prime}_{\rm{HK}}}$ and/or
$B_l$ measurements for 954 mid-F to mid-M stars derived from
spectropolarimetric observations contained within the PolarBase database. Our
magnetically active sample complements previous stellar activity surveys that
focus on inactive planet-search targets. We find a positive correlation between
mean $\log{R^{\prime}_{\rm{HK}}}$ and mean $\log|B_l|$, but for G stars the
relationship may undergo a change between $\log{R'_{\rm{HK}}}\sim-4.4$ and
$-4.8$. The mean $\log{R^{\prime}_{\rm{HK}}}$ shows a similar change with
respect to the $\log{R^{\prime}_{\rm{HK}}}$ variability amplitude for
intermediately-active G stars. We also combine our results with archival
chromospheric activity data and published observations of large-scale magnetic
field geometries derived using Zeeman Doppler Imaging. The chromospheric
activity data indicate a slight under-density of late-F to early-K stars with
$-4.75\leq\log{R'_{\rm HK}}\leq-4.5$. This is not as prominent as the original
Vaughan-Preston gap, and we do not detect similar under-populated regions in
the distributions of the mean $|B_l|$, or the $B_l$ and $\log{R'_{\rm HK}}$
variability amplitudes. Chromospheric activity, activity variability and
toroidal field strength decrease on the main sequence as rotation slows. For G
stars, the disappearance of dominant toroidal fields occurs at a similar
chromospheric activity level as the change in the relationships between
chromospheric activity, activity variability and mean field strength.
