OK, a few months ago, I was messing around, looking for information on Back to the Future, and I found a wiki dedicated to sound effects, not only cataloguing the sounds themselves, but also movies/TV shows/video games/whatever that the sounds were used in. Of course, among them are various siren sound effects, from vintage to modern. Here are a few examples:
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN,_POLICE_-_ELECTRONIC,_STEADY_02 - Federal Signal PA-15/PA-20 running in "Manual" mode, heard in many TV shows and movies from the 60s to the 80s.
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN,_EMERGENCY_-_YELPER_TYPE,_STEADY - Federal Signal PA-15A/PA-20A Series E running in "Yelp" mode.
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN_-_CONSTANT_WAILS_AND_YELPS - Unitrol 800 running in "Wail" and "Yelp" modes
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN,_POLICE_-_ELECTRONIC,_STEADY_02 - Federal Signal PA-15/PA-20 running in "Manual" mode, heard in many TV shows and movies from the 60s to the 80s.
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN,_EMERGENCY_-_YELPER_TYPE,_STEADY - Federal Signal PA-15A/PA-20A Series E running in "Yelp" mode.
https://soundeffects.fandom.com/wiki/Sound_Ideas,_SIREN_-_CONSTANT_WAILS_AND_YELPS - Unitrol 800 running in "Wail" and "Yelp" modes