  Two identical chaotic oscillators that are mutually coupled via time delayed
signals show very complex patterns of completely synchronized dynamics
including stationary states and periodic as well as chaotic oscillations. We
have experimentally observed these synchronized states in delay-coupled
electronic circuits and have analyzed their stability by numerical simulations
and analytical calculations. We found that the conditions for longitudinal and
transversal stability largely exclude each other and prevent e.g. the
synchronization of Pyragas-controlled orbits. Most striking is the observation
of complete chaotic synchronization for large delay times, which should not be
allowed in the given coupling scheme on the background of the actual paradigm.
