Morse code

Morse code is one of the most commonly used or at least one of the oldest Codes and Alphabets used by amateur radio operators to transmit information over long distances.

History
Main article: Morse code

Up until fairly recently (early 2000's in many countries) Morse (CW) proficiency was a requirement for obtaining an amateur licence, or at least to get access to low frequency (paradoxically called High Frequency, HF, below 30Mhz). In 2003, the ITU removed the requirement for countries to demand morse code proficiency

International morse code table
The international morse code is composed of five elements:


 * 1) short mark, dot or 'dit' (·) — one unit long
 * 2) longer mark, dash or 'dah' (–) — three units long
 * 3) intra-character gap (between the dots and dashes within a character) — one unit long
 * 4) short gap (between letters) — three units long
 * 5) medium gap (between words) — seven units long

Comparison between international and american code sets
Radio traffic uses International Morse only; while the original railroad landline telegraph system used American Morse code, which is now obsolete.

Prosigns
An error is indicated as a series of E's or E s:

Codes
See Q codes