The Siren Board

Yet again, reporting another mishap from the FDL siren system. For the most part, today's test went smoothly, with the sirens sounding their usual three minutes. Before the test concluded, another T128 (Most likely the same one from my last post) seemed to have a sort of fail, as it started winding down too early, then came back to finish the test, but it sounded slightly worse than before it's mishap. I've heard nothing from the scanner so far. Any ideas about what happened?

A failing contactor would be my guess.

The way you describe it makes it sound like the rectifier failed and the siren auto transferred to the batteries, which would run it at a lower RPM. Not sure though, as I don't know how ASC sirens handle that.