(top) CAFOS CAHA spectra of the detected nebular emission lines from PN G 075.9+11.6. The spectrum has been obtained by integrating the detected emission lines at s1 (see Fig. 1) between 38′′ and 75′′ north of 2M1931+4324. (bottom) Spectrum of the high-excitation filament. The spectrum has been obtained by integrating the detected [O iii]λ5007 emission line at s2 (see Fig. 1) in a region of 8′′ centered on the filament.