The second Caltech-Jodrell Bank VLBI survey. 1: Observations of 91 of 193 sources

We define the sample for the second Caltech-Jodrell Bank VLBI survey. This is a sample of 193 flat- or gigahertz-peaked-spectrum sources selected at 4850 MHz. This paper presents images of 91 sources with a resolution of ~1 mas, obtained using VLBI observations at 4992 MHz with a global array. The remaining images and the integrated radio spectra will be presented in a forthcoming paper by Henstock et al.