Operation of a hydrogen maser with a state-mixed beam

Operation of a hydrogen maser with a beam having equal populations of atoms in the (F = 1, m
F
= 1) and (F = 1, m
F
= − 1) hyperfine states is described. The elimination of the magnetic inhomogeneity shift by this means is confirmed. The effect of the state mixing on the frequency stability of the maser is investigated.