  We report on an ongoing effort to image active galactic nuclei simultaneously
observed at 2.3 and 8.6 GHz in the framework of a long-term VLBI project RDV
(Research and Development - VLBA) started in 1994 aiming to observe compact
extragalactic radio sources in the astrometric/geodetic mode. Observations of
bright extragalactic sources are carried out bi-monthly making up to six
sessions per year with participation of all ten VLBA antennas and up to nine
additional (geodetic and EVN) radio telescopes. Analysis of single-epoch
results for 370 quasars, BL Lacs and radio galaxies is presented. We discuss
VLBI core properties (flux densities, sizes, brightness temperatures), spectral
characteristics of the cores and jets, evolution of brightness temperatures in
the jets.
