Observed N_Ka,Kc = 8_0, 8–7_0, 7, 9_0, 9–8_0, 8, and 10_0, 10–9_0, 9 lines of ortho-CH₂C₃N in TMC-1 in the 31.0–50.4 GHz range. The most intense hyperfine components for each rotational transition are shown. The abscissa corresponds to the rest frequency, assuming a local standard of rest velocity of 5.83 km s⁻¹. Blanked channels correspond to negative features produced in the folding of the frequency switching data. The ordinate is antenna temperature in millikelvins. Curves shown in red are the computed synthetic spectra.