Morse code

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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: Wikipedia: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


Character Code Character Code Character Code Character Code Character Code Character Code
A · — J · — — — S · · · 1 · — — — — . · — · — · — : — — — · · ·
B — · · · K — · — T 2 · · — — — , — — · · — — ; — · — · — ·
C — · — · L · — · · U · · — 3 · · · — — ? · · — — · · = — · · · —
D — · · M — — V · · · — 4 · · · · — '' · — — — — · + · — · — ·
E · N — · W · — — 5 · · · · · ! — · — · — — - — · · · · —
F · · — · O — — — X — · · — 6 — · · · · / — · · — · _ · · — — · —
G — — · P · — — · Y — · — — 7 — — · · · ( — · — — · " · — · · — ·
H · · · · Q — — · — Z — — · · 8 — — — · · ) — · — — · — $ · · · — · · —
I · · R · — · 0 — — — — — 9 — — — — · & · — · · · @ · — — · — ·

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.

Symbol International American
International and American Morse Codes
A .- .-
B -... -...
C -.-. ..-.
D -.. -..
E . .
F ..-. .-.
G --. --.
H .... ....
I .. ..
J .--- -.-.
K -.- -.-
L .-.. ----
M -- --
N -. -.
O --- .-.
P .--. .....
Q --.- ..-.
R .-. .-..
S ... ...
T - -
U ..- ..-
V ...- ...-
W .-- .--
X -..- .-..
Y -.-- ..-..
Z --.. ....
1 .---- .--.
2 ..--- ..-..
3 ...-- ...-.
4 ....- ....-
5 ..... ---
6 -.... .....
7 --... --..
8 ---.. -....
9 ----. -..-
0 ----- -----


Prosigns

Sign Code Meaning
AR ·-·-· Stop (end of message) +
AS ·-··· Wait
BK -···-·- Break, or "back-to-you".
BT -···- Separator within message =
C -·-· Yes - Confirm - Affirmative
CL -·-··-·· Going off the air - "clear" or "closing down"
K -.- "go" or "over" - another station is invited to reply
KN -·--· Invitation to a specific named station to transmit - "go oNly".
SK ···-·- End of contact
SN ···-· Understood
SOS ···---··· Distress - imminent danger to life or property.

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

······· Error, correct word follows (six or more dots in a row)
· · · Error

Codes

See Q codes

See also

Operating procedures
Operation Callsigns and ITU prefixes * Codes and Alphabets * Modes * Morse code * Nets * UK licensing * Terminology
DX and Contesting Awards and Certificates * DXCC * DX cluster * Field day * Gridsquares * Logging * QSL and QSL Bureaus * Records - Distance
Emergencies Emergency Frequencies * ARES * IRESC * SATERN * Weather spotting
QRP Trail-Friendly Radio
Utilities Beacons (/B) and Time Beacons