A telegraph key or Morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. Keys are used in all forms of electrical telegraph systems, including landline telegraphy and radio telegraphy. An operator uses the telegraph key to send electrical pulses of two different lengths: short pulses, called dots or dits, and longer pulses, called dashes or dahs. These pulses encode the letters and other characters that spell out the message.
A straight key style of telegraph key – model J-38, a key used by U.S. military during World War II, and frequently re-used by radio amateurs
a Wright Brothers telegraph key (missing its knob)
A Morse Key from G. Hasler, Bern (1900) first used by Gotthard Railway
Early "bug" telegraph key invented in 1913 by Weston Hadden
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs. Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy.
This Morse key was originally used by Gotthard railway, later by a shortwave radio amateur
Single needle telegraph instrument
Telegraph key and sounder. The signal is "on" when the knob is pressed, and "off" when it is released. Length and timing of the dits and dahs are entirely controlled by the telegraphist.
Morse code receiver that records on paper tape