Two portions of the highest-quality spectrum from the Tautenburg observations, showing the H_α (upper left panel) and H_β (upper right panel) spectral features. When this spectrum was obtained on 15 September 2019, the phases of both binaries were Φ_A = 0.088 and Φ_B = 0.706. The lower plot shows the cross-correlation function of this spectrum. All four components are distinguishable in H_α, but are hardly detectable in H_β.