Evolution of the radio spectra over the campaign period from 2012 January 28 to April 17 (MJD 55 954, 55 975, 55 990, 56 009, 56 018 and 56 034). The first radio outburst (11 in Fig. 8) dominates the spectra in the first epoch, while in the second epoch new outburst (12a in Fig. 8) is apparent in the high frequencies. In the third epoch (12b) becomes visible in the highest frequencies with the peak moving to lower energies in the fourth and fifth epochs.