We present deep L-Band observations of the equatorial field centered on the z=6.3 SDSS QSO, reaching a 1 sigma sensitivity of ~2.5uJy at the center of the field. We extracted a catalog of 1489 radio sources down to a flux density of ~12.5uJy (5 sigma) over a field of view of ~30' diameter. We derived the source counts accounting for catalog reliability and completeness, and compared them with others available in the literature. Our source counts are among the deepest available so far, and, overall, are consistent with recent counts' determinations and models. We detected for the first time in the radio band the SDSS J1030+0524 QSO (26+/-5uJy). We derived its optical radio loudness R_O_=0.62+/-0.12, which makes it the most radio quiet AGN at z>~6 discovered so far and detected at radio wavelengths. We unveiled extended diffuse radio emission associated with the lobes of a bright FRII radio galaxy located close to the center of the J1030 field, which is likely to become the future BCG of a protocluster at z=1.7. The lobes' complex morphology, coupled with the presence of X-ray diffuse emission detected around the FRII galaxy lobes, may point toward an interaction between the radio jets and the external medium. We also investigated the relation between radio and X-ray luminosity for a sample of 243 X-ray-selected objects obtained from 500 ks Chandra observations of the same field, and spanning a wide redshift range (0~<z~~87%) show a radio-to-X-ray radio loudness R_X_<-3.5, classifying these objects as radio quiet.

Cone search capability for table J/A+A/668/A133/j1030 (Catalog)