A detection survey of bright extragalactic radio sources with 3 mm VLBI is described. The sample is based on a centimeter-wavelength flux density limit, with account taken of the spectral shape. Of the 116 sample members, 79 sources were observed and 14 were detected. This detection rate is considerably lower than had been anticipated, the discrepancy being fully attributable to attained sensitivities roughly a factor of 2 poorer than those planned, and routinely achievable with current arrays. The small number of detections precludes any firm conclusions about source detectability as a function of source type, redshift, or other variable. However, the results allow us to demonstrate that, at easily attainable sensitivity levels, between 30 and 50 sources would be detected in a similar survey. Because the sample does not include all potentially detectable sources, in particular those with inverted spectra above 5 GHz, these numbers represent a lower limit to the number of detectable continuum sources accessible to the current 3 mm VLBI network at any given time.
Galaxies: Quasars: General - Techniques: Interferometric