We present optical spectra and redshift measurements for 178 flat-spectrum objects from the Parkes quarter-Jansky flat-spectrum sample Table A1 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( 130.79.128.5 ) or via http : //cdsweb.u-strasbg.fr/cgi-bin/qcat ? J/A+A/ .
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 0.25 Jy < S _ { 2.7 GHz } < 0.5 Jy , 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 .
uasars : general radio