  The accuracy in position and flux density of 19 large radio continuum source
catalogues has been determined using SPECFIND, a new tool recently made
available through the CDS. The ~67000 radio continuum spectra with three or
more frequencies produced by SPECFIND were used to cross-correlate sources from
different catalogues and to calculate offsets in right ascension and
declination in the various catalogues with respect to the positions given in
the NRAO VLA Sky Survey (NVSS) catalogue, which was adopted as a reference. The
flux densities reported in the catalogues were compared to those predicted by
the composite spectra, enabling us to assess the quality of the flux density
calibration of the different catalogues.
