It's most certainly an STL-10.
A. Correct tone.
B. Sounds omnidirectional (although the wind can play tricks on one's ears).
C. Having heard an STL-10 go off in the FD system of the next town over from me for *years*, it hhas that distinct sound of an STH on Xanax.
I am, though, a bit confused on the cycling. Is she (yes...she.

) manually controlled?
EDIT: I don't seem to recall the old Melville FD'd STL winding up like that (it's been literally almost decades, tho.)