Simulated 7C data, assuming Ω_M = 1 and Ω_Λ = 0, for the six planes in [PDzα] parameter space and additionally a plot of the jet power Q₀ vs. rest‐frame luminosity at 151 MHz and a plot of the age of each source at the point we observe it against redshift. Solid circles indicate objects at z ≥ 2, crosses indicate objects with 2 > z ≥ 1.5, open circles indicate 1.5 > z ≥ 0.8, and dots indicate sources with z < 0.8.