Recovered net flux density as a function of the injected flux density for various angular diameters and instruments. Red, magenta, blue, and green curves are injections in LOFAR (HBA at 144 MHz), uGMRT (band 3 at 400 MHz, 6 and 10 h on source are shown with solid and dotted lines, respectively), uGMRT (band 4 at 700 MHz), and JVLA (DnC+BnC array, L band at 1.5 GHz) datasets, respectively. The expected flux density integrated up to 3r_e of a representative radio halo with M₅₀₀ = 5 × 10¹⁴ M_⊙ is indicated by a dashed vertical line and can be exploited to estimate effective losses (see Table 3 and discussion in Sect. 6).