Neat video from Germany. This siren has been inactive since 2007, and the city decided to revive it after all these years. It sounds a bit rough at first, but it gets itself together after a few cycles of the warning tone. It's still running with its original diesel engine-driven generator and air compressor, which is interesting as most of these sirens have since been converted to HLS-373s by the cities with either an electric motor being installed to drive the compressor or a separate compressor being added to the bunker and plummed into the lines feeding the tank. Seeing another HLS become active is nice, given how rare these unique sirens are.
https://www.youtube.com/watch?v=NTcdg1Z9bc8