Vibroplex

The Vibroplex is a type of semi-automatic telegraph key, often referred to as a "bug," widely used by telegraph operators. It was invented in 1904 by Horace G. Martin and manufactured by the Vibroplex Company, which he also founded.

Unlike a straight key, which requires the operator to manually form each dot and dash, the Vibroplex automatically creates a series of dots when the lever is pushed to one side. The operator controls the duration and spacing of the dashes by manually moving the lever to the opposite side. This semi-automatic operation allows for faster and more consistent sending speeds than a straight key, particularly for sending dots.

The Vibroplex consists of a weighted pendulum, a lever, and adjustable contacts. When the lever is pressed to the dot side, the pendulum oscillates, creating a series of electrical pulses (dots). When pressed to the dash side, the lever closes a circuit for the duration it is held, producing dashes.

The Vibroplex became a popular tool among professional telegraphers, including those working for railroads, news agencies, and the military. Its unique sound and feel are recognizable to experienced operators. While largely superseded by electronic keyers and computer-based systems in modern communications, the Vibroplex remains a popular item among amateur radio operators and collectors, prized for its historical significance and distinctive operating characteristics. The Vibroplex Company continues to manufacture and sell these keys, maintaining the original design with only minor modifications over the years.