  We present optical spectra and redshift measurements for 178 flat-spectrum
objects from the Parkes quarter-Jansky flat-spectrum sample. These spectra were
obtained in order to compile a complete sample of quasars for use in a study of
quasar evolution. We present a composite optical spectrum made from the subset
of 109 quasars that have flux densities in the range 0.25Jy < S(2.7GHz)< 0.5Jy,
and make a comparison with a composite for radio-quiet QSOs from the Large
Bright Quasar Survey. Our large sample of radio-loud quasars allows us to
strengthen previous reports that the Ly-alpha and CIV emission lines have
larger equivalent width in radio-loud quasars than radio-quiet QSOs to greater
than the 3-sigma level. However we see no significant difference in the
equivalent widths of CIII] or MgII. We also show that the flux decrements
across the Lyman-alpha line (D_A) measured from these spectra show the same
trend with redshift as for optically selected QSOs.
