Mock observations of the Faraday spectrum shown in Fig. 2a. The spectrum has been observed over two frequency ranges: a) 110 to 250 MHz, similar to the LOFAR high band antennas and b) 300 to 900 MHz similar to the low frequency portion of the GMIMS survey. In each figure, the Faraday spectrum has been deconvolved using RMCLEAN. The black line represents the restored spectrum, while the RMCLEAN components are shown as vertical grey lines (red in the online version).