Teaching telegraph key. There is such a telegraph key, produced by the USSR. The key has a convenient but not reliable adjustment, since screws are used in the adjustment with standard thread and pitch. There would be screws with a shallow step, it would be much better and more convenient. The manipulator is resilient, although it is made of a thin metal strip, without facets. At the handle of the manipulator is a handle, with a composite skirt. The skirt is made of cardboard. Sometimes the skirt leaves its native place or bends, it takes a skirt to make a new one. The casing of the telegraph key has 4 holes for fixing the key to the table.
Update: 20180510 author: