Maps of the polarized calibrators 3C286 (left panel) at 14 GHz with 150 mas resolution, and 3C138 (right panel) at 42 GHz with 45 mas resolution. For 3C286, both the Stokes I and polarized flux density are dominated by the nuclear emission; the Stokes I extended emission accounts for only 166 mJy compared to 3.58 Jy for the nuclear core. For 3C138, the situation is quite different—the Stokes I extended emission is much stronger, accounting for 571 mJy compared to 1.710 Jy for the nucleus, while the polarized emission at this band is about equal between the jet and the nucleus.