High Angular Resolution Monitoring of Prominent AGN at 86 GHz

We report results from 3mm-VLBI observations of 3C273 and 3C454.3 during the period 1994-1997. In both sources the images show superluminal motion in feature-rich jets. Due to the improved uv-coverage in the later experiments, the jets can be followed further out than previously. Comparision with maps obtained at longer wavelengths allows to determine spectral gradients along the jets. Opacity effects lead to transverse displacements of the jet ridgelines. These displacements appear to be different in 3C273 and 3C454.3.