A low-dispersion Keck I spectrum of SN 1980K taken in August 1995 (t = 14.8 yr after explosion) and a November 1997 MDM spectrum (t = 17.0 yr) show broad 5500 km s^{ -1} emission lines of H\alpha, [O I] 6300,6364 A, and [O II] 7319,7330 A. Weaker but similarly broad lines detected include [Fe II] 7155 A, [S II] 4068,4072 A, and a blend of [Fe II] lines at 5050--5400 A. The presence of strong [S II] 4068,4072 A emission but a lack of [S II] 6716,6731 A emission suggests electron densities of 10^{ 5-6} cm^{ -3}. From the 1997 spectra, we estimate an H\alpha flux of 1.3 \pm 0.2 \times 10^{ -15} erg cm^{ -2} s^{ -1} indicating a 25% decline from 1987--1992 levels during the period 1994 to 1997, possibly related to a reported decrease in its nonthermal radio emission.
Categories: astro-ph