Change in the Position of the Radio Source 1328+254 S and X-Bands

In this paper, an analysis was carried out of the time series of the coordinates of the radio source 1328 + 254, obtained from VLBI observations in the S and X bands. To account for the ionospheric corrections, GNSS TEC data were used, which made it possible to derive independent position estimates for each band. Our analysis showed that the main jump in the combined coordinates—previously identified by other authors—was driven by changes in the X-band coordinates while the S-band values remained stable. Additionally, a less pronounced jump observed in recent years was caused by variations in the S-band coordinates, whereas the X-band coordinates stayed constant.