Real vs imaginary part of the HH cross-calibrated visibilities of the secondary calibrator for a typical MeerKAT 5 h observation. The colour represents the density of the points in the plot. The distribution of points is perfectly circular in the inner region, where the density of points is higher, and shows some asymmetries only in the outer sparsely populated region. The standard deviation of the visibility amplitude and phase is typically ∼1 Jy and ∼5 deg.