Balmer and He I lines variability with the long cycle. The green spectrum is at ϕ = 1027.392, ϕ_L = 0.391, while the black one is at ϕ = 1090.395, ϕ_L = 0.07. The line blueward of He I 4026 is He I 4009, while the one redward of He I 4471 is Mg II 4481. The spectra in the first four panels are continuum-normalized, while the He I 5876 and 6678 were normalized with the continuum level at −1500 km s⁻¹. The units on the y-axes are arbitrary units of flux.