Top panel: an excerpt of the total intensity (Stokes I) time series dedispersed at the DM of the injected pulses and exhibiting large amount of red noise. Middle panel: a view of the Stokes I time series dedispersed at the DM of the injected pulses and after subtraction of the zero DM time series. Bottom panel: time series of the linear polarisation L_d after dedispersion and the correction of Faraday rotation at RM = 10 000 rad m⁻². For clarity, the average value of L_d has been subtracted from it. In all three panels, the grey dashed lines indicate the location of the three injected pulses.