Contour plot of dependence of the peak frequency of gyrosyn-chrotron emission as a function of magnetic field strength in the radio-emitting source and the product of total number density of accelerated electrons and size scale of the emission NL. Two different sets of contours are shown, which bracket the inferred values of δ_r seen in the frequency-dependent decay of event C2 in SCR0838 shown in Fig. 11. The larger values of NL provide more constraints on the field strength in the radio-emitting region, in order to be consistent with the low peak frequency and the smaller value of δ_r.