Superposition of the 228 752 MHz transition spectrum at the ethylene glycol peak (in black) with the average spectrum of 11 transitions that have no blends near 5 km s^-1 (in red) and the average spectrum of 14 transitions that have no blends near 10 km s^-1 (in blue). All spectra are normalized to 1. A Gaussian fit to the 228 752 MHz line is shown in green. A faint wing is visible at lower velocities.