  We report and discuss the results of a 22 cm radio survey carried out with
the Australia Telescope Compact Array (ATCA) covering the A3528 complex, a
chain formed by the merging ACO clusters A3528-A3530-A3532, located in the
central region of the Shapley Concentration. Simultaneous 13 cm observations
are also presented. Our final catalogue includes a total of 106 radio sources
above the flux density limit of 0.8 mJy. By cross correlation with optical and
spectroscopic catalogues we found 32 optical counterparts, nine of them
belonging tothe A3528 complex. We explored the effects of cluster mergers on
the radio emission properties of radio galaxies by means of the radio
luminosity function (RLF) and radio source counts. We found that the radio
source counts are consistent with the background counts, as already found for
the A3558 complex (Paper III). The RLF for this complex is consistent, both in
shape and normalisation, with the general cluster luminosity function for
early-type galaxies derived by Ledlow & Owen (LO96). This result is different
from what we obtained for the A3558 merging complex, whose RLF is significantly
lower than LO96. We propose that the different stage of the merger is
responsible for the different RLFs in the two cluster complexes in the core of
the Shapley Concentration. The early stage of merger for the A3528 complex,
proposed by many authors, may have not yet affected the radio properties of
cluster galaxies, while in the more much advanced merger in the A3558 region we
actually see the effects of this process on the radio emission.
