[rotorwrench]

Hutchins was the original patent holder for the motor driven Klaxon type horns. A person has to inspect the sounding diaphragm from time to time to make sure it hasn't cracked. They will fatigue over time and will eventually crack. The diaphragm also has the adjustable sounding knub or wedge where the wavy rotor on the motor makes contact. Too little contact will eventually make no sound at all. Too much contact will make a harsh sound and is hard on the diaphragm. If the adjuster knub is tapered to a point like a chisel then it has to be aligned to where the chisel point is somewhat parallel with the waves in the rotor or basically pointing toward the center of the rotor disk. This way the rotor can move more easily over the sounding adjuster knub. Some are rounded on the tip so they can be adjusted to any position of rotation. Usually only slight adjustments are necessary for wear over time. The condition of the motor armature and brushes also play a part in how well they sound. Also, if the armature bearings get loose, it will be harder to maintain a uniform sound from these type units.

Everything wears out eventually.