The beam-gas technique has been used to obtain the VUV spectra of the ions of Si, S and O in the 500–1200 Å range. System resolutions of 0.6–0.8 Å were used to record the various spectra, which were analyzed by the fitting routine SAMPØ. Each ion was accelerated at various energies between 0.4 and 2.0 MeV in an effort to make charge state assignments of the newly observed lines by the intensity variation method. A large number of new but relatively weak lines in Si and O have been analyzed. The S spectra contained an abundance of both weak and strong lines previously unclassified.