At my old elementary school (now called New Urban High School), I remember a red horn which, for the first clue, has these diagonal vents on it. Down below on each of those were the Edwards 270SPO pull stations. This kind of horn scared me a lot. Its tone, to provide the second clue, was in the key of C-major of about 277.18 Hz.
My question to be answered is: what make and model would these red horns with the diagonal vents be? I’d like to think they are Simplex units. The last significant upgrades/additions to the elementary school were performed in 1959 (and the annex was originally built in 1956), but that may not exactly be how old these Edwards and Simplex fire alarm units are. Its tone was key of C-major (277.18 Hz).
Thank you,
Ben Edge (ClassicTVMan1981X)