The infrared spectrum of the TeH radical in its X2Π state has been recorded using an intracavity CO laser magnetic resonance (LMR) spectrometer. Seven of the eight naturally occurring Te isotopomers were observed, with resonances originating from the first three vibrational levels; many were recorded as Lamb-dips. These observations have been combined with existing data for TeH and TeD in the X2Π state and used to determine the parameters of an N2 Hamiltonian, including isotopic scaling and nonadiabatic corrections. The data are well described by the parameters. The different isotopic dependences of the effects of the parameters AD and γ has allowed their separation and the extent to which TeH shows Hund’s case (c) coupling is discussed. Trends displayed by the chalcogen monohydrides are considered.