Pulse profiles averaged over all observations of the pulsars at 149 MHz (black), 334 MHz (red), and 1532 MHz (blue) with bandwidths of 78, 64, and 384 MHz. The profiles were aligned by applying the model in Table 2. Then, all profiles were rotated such that the highest peak of the LOFAR pulse profile is located at phase ϕ = 0.25. The pulse profiles at 149 MHz have 1024 phase bins, while the profiles at 334 and 1532 MHz were rebinned from 512 and 1024 to 256 and 512 phase bins, respectively.