Quoted from Passave:I have a old juke (rock ola) that used a trigger plate for those air horns you see people use at football games, If you move cashbox WWWWWAAAAA... It was an option for that machine that is not even in the manual and aparently not many people bought them, because they are super hard to find....It took me years to understand what I was even looking at.
Also, the large Rowe change machines had the air horn alarm that activated as crooks tried to pry the door open with a wrecking bar. If the lock was properly opened. the locking rods/bolts moved away from the wood lever that activated the air horn. No battery required...