Catching the radio flare in CTA 102 - III. Core-shift and spectral analysis C. M. Fromm, E. Ros, M. Perucho, T. Savolainen, P. Mimica, M. Kadler, A. P. Lobanov and J. A. Zensus A&A, 557 (2013) A105 Published online: 11 September 2013 DOI: 10.1051/0004-6361/201321784