A preliminary analysis of the 2CH excitation band in C2H2–N2O in the 1.5 mm range (K. Didriche, C. Lauzin, P. Macko, M. Herman and W.J. Lafferty, Chem. Phys. Letters 469, 35 (2009).), only considering 117 low J-, and Ka- vibration-rotation lines, is significantly extended thanks to the analysis of new spectra including very regular series of lines with J/Ka up to 31/15. 1271 b-type lines were assigned. Perturbations are briefly discussed. The rotational temperature in the experiments is estimated to be 20K and the upper state mean half-time is 1.6 ns for non perturbed levels. The previous analyses of the 2CH þ torsion band in C2H2–N2O and in C2H2–CO2 (C. Lauzin, K. Didriche, T. Fo¨ ldes and M. Herman, Mol. Phys. 109, 2105 (2011).), are also extended to include 286 and 234 lines, respectively, also correcting for calibration errors. New rotational constants are obtained using a rigid rotor Hamiltonian by simultaneously fitting the ground, 2CH and 2CH þ torsion states in C2H2–N2O, and the latter state, only, in C2H2–CO2.