The electron-nucleus interaction is studied in Ga-substituted Tm-ortho
ferrite at the temperatures of the beginning and the end of the spin-r
eorientational phase transition GAMMA2(G(Z)F(X)) --> GAMMA4(G(X)F(Z))
using the technique of NMR of the Fe-57, Ga-69, and Ga-71 nuclei. Indi
rect hyperfine fields are for the first time estimated on the gallium
nuclei in orthoferrites. The results obtained are discussed.