Synchrotron spectrum of 4C 29.41 between 54 and 380 MHz. The orange curve shows the case where no uv-cut was applied while imaging, thus including the contribution of extended emission, that increases the flux density especially at lower frequency. The blue curve shows instead the case with a minimum uv-cut of 1.6 kλ, which roughly corresponds to 2′ (i.e. the larger scale emission is not present).