All the exposures below were for 8s; the standard arc exposure is 2s, but only one out of four lamps was plugged in.
All the following plots have the same vertical scale, and show
every 40th spectrum on the image.
The single red, yellow, blue, green, and black traces are spurious.
Four images are shown for each of three wavelength ranges: one "existing" Ne-only lamp exposure, and three exposures from the new lamps. All the lamps are pretty stable, and the new lamps show useable Ar lines.