Panels (1) to (4) show the Stokes I contours and linear polarization intensity (shown in gray-scale) of NRAO 150 for 12 (1), 15 (2), 24 (3), and 43 GHz (4). The purple ellipse in panel (4) shows the restoring beam used for all four frequencies. The contours start at 5σ_I up to the peak increasing by a factor of 2. The blue ticks in panels (1) to (4) show the average EVPA across a 5 × 5 pixel region for each frequency.