Thought I'd show ya what is going on inside on in case you haven't seen.
They are adjustable and rebuild able unlike newer horns.
When power 6v or 12v is applied to the horn a coil pack is magnetized which causes the bar on the thin buzzer plate to be drawn towards the now magnetized metal block on either side of the coil pack. As the plate approaches the magnet it then contacts the tab on the point plate, which in turn breaks contact with the points turning the power off to the coil pack. This happens very rapidly causing the metal plate to jump back and forth shaking the buzzer plate and making noise/vibration.
When you turn the adjuster screw it changes the height of the point tab which changes the amount of contact the points make and then changes the tone of the horn.
Maybe the experts can chime in if I missed something or got something wrong.
