Histograms of the 1.4 GHz aperture flux density of the ACT (a) and MaDCoWS (b) cluster catalogs. Panel c: normalized cumulative histogram of the same data, cut at the aperture noise of 0.3 mJy, to better illustrate the difference in infill between the two samples. The fluxes shown are all for a 1.2′ radius aperture, while the percentage infill is the approximate infill of the SZ signal as described in Sect. 7.1.2. We note that due to differences in average redshift and spectral index of the ACT and MaDCoWS clusters, the same measured flux density at 1.4 GHz does not correspond to the same percentage infill. The ACT clusters show on average significantly more radio infill at 1.4 GHz than their MaDCoWS analogs.