We have tested the operation and spectral coverage of two different types of EUV light sources for EUV characterization of astronomical mirror coatings, gratings, filters and detectors. Based on successes reported by another group investigating EUV-range K and L shell emission, we tested the feasibility of using Bremmstrahlung emission from a standard x-ray tube with the beryllium window removed. The second source is a Penning gas discharge source reported previously. The range of characterization and combinations of cathode and gas materials has been extended. Using the C/Ne and C/CO2 combinations provides nearly full coverage of the 200-600 ? spectral range with a high density of spectra lines. Use of carbon cathodes as opposed to the standard aluminum or magnesium cathodes allows one to operate the source for a long period of time before having to break vacuum and replace the disposable cathodes.
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