Angular power spectra of the various systematic effects at 30GHz, compared to the CMB and foreground temperature and polarization spectra and to the instrumental noise from half-ring (HR) difference maps. The CMB TT and EE spectra are best fits to the Planck cosmological parameters (see Figs. 9 and 10 in Planck Collaboration I 2016) filtered by the LFI window functions. The example CMB B-mode spectrum is based on Planck-derived cosmological parameters and assumes a tensor-to-scalar ratio r = 0.1, a tensor spectral index n_T = 0, and no beam-filtering. The thick dark-grey line represents the total contribution. The dotted dark-green line is the contribution from the far sidelobes that has been removed from the data and is therefore not considered in the total.