De-trended 2 and 8 GHz light curves of 0954+658 (left and right panel respectively, green dots) plotted together with the average yearly pattern obtained after removing the data points covering the 1981.1 event while stacking the remaining data and averaging them (black dots). The stacked data are multiplied by a factor nine for a better comparison between the datasets. The peak-to-dip difference in the 1981.1 event is about 20 times greater than the spread in the noise level of the source. Blue and orange arrows indicate the time of maximum and minimum solar elongation of the source.