  We present new, high resolution radio images of sources associated with cD
galaxies and X-ray cavity systems located in cluster cores. The cavity
properties derived from archival Chandra observations give reliable estimates
of the total jet power and age independently of the radio synchrotron flux. We
combine the X-ray data and VLA radio images taken at multiple frequencies to
investigate several fundamental properties of cluster radio sources, including
their radiative (mechanical) efficiencies, magnetic field contents, and
particle contents, and we evaluate the assumption of equipartition in these
systems. We show that high radio frequencies probe the current AGN output,
while frequencies at or below 327 MHz trace the history of AGN activity in the
cores of clusters over the past several hundred million years.
