Morse code most common letter in English, the letter "E", has the shortest code: a single dot. Because the Morse code elements are specified by proportion rather than specific time durations, the code is usually transmitted at the highest rate that the receiver is capable of decoding. The Morse code transmission rate ("speed") is specified in "groups per minute", commonly referred to as "words per minute". Morse code is usually transmitted by on-off keying of an information carrying medium such as electric current, radio waves, visible light or sound waves. The current or wave is present during time period of the dot
Morse code abbreviations only. To station S1 from station S2. Roger (R) Thank you (TU) see you again (CUAGN) Best regards (73) To station S1 from station S2: Signing off. In International Morse code there is no "distinct" dot-dash sequence defined only for the mathematical equal sign [=]; rather the same code ("–···–" or "dah di di di dah") is shared by "double hyphen" [=] and the procedural sign for "section separator" notated as . It is fairly common in the "Recommended International Morse Code" for punctuation codes to be shared with prosigns. For example, the code for plus or cross [+] is