Morse code FAQ

Q. What does CW mean?

A. CW stands for “continuous wave”. Most hams refer to Morse code when they talk about “CW”. So what does CW have to do with Morse code?. Morse is the code used via the CW medium, or “mode”, of communication. Morse code can be created by means of a flashlight, signal flags, mirrors, even a stick hit against a water pipe can be used to communicate with Morse code, or any code for that matter! Telegraph operators used Morse code over the telegraph wires back in the 1800′s to send messages. These messages were known as “telegrams”. People of that time relied on the telegraph operators to pass information over great distances. Telegraph operators also checked the current weather conditions across the country, making sure that the trains ran on schedule, So, it’s no surprise that when radio came along at the turn of the century, Morse code became the standard in communication, as many telegraph offices went “wireless”.

As the art of radio progressed, most ships became equipped with transmitters and receivers. The ship to shore operators used Morse code as their only means to communicate with other ships and land stations. The R.M.S. Titanic used Morse code to send it’s ill-fated distress signal “CQD”.

Q. What is Morse code?

A. Morse code is named after it’s inventor Samuel F.B. Morse, 1791 – 1872. Morse invented the code (and the electromagnetic telegraph) in 1836. The code consists of a series of dots and dashes. Each letter of the alphabet and numbers 0 through 9 have individual combinations assigned to them. Some people can copy code at speeds of up to 70 words per minute. Of course that is more the exception than the rule, most hams copy code in the 10 to 30 word per minute range. Once you get over the learning curve, Morse code becomes a second language. You begin to hear “words”, not just each individual letter. You begin to recognise the rhythm of the words so you can easily pick them out and follow along with the conversation.

Q. What does SOS stand for?

A. The emergency code “SOS” was chosen not because it means anything, but because its Morse code is very simple to remember and transmit: dot dot dot dash dash dash dot dot dot. This combination of letters was established in 1906 by the International Radio Telegraphic Convention in Berlin. It is still used as an international distress signal, especially by ships and aircraft.

Many people have made up acronyms for SOS, such as “Save Our Souls,” “Save Our Ship”, “Sink Or Swim”, “Send Out Sailors”, “Save Our Skins”, and “Send Out Someone”, but these were invented after the fact.

The letters S O S in Morse code are the sounds … — … which are the extremes of opposite in Morse code. Consider that 911 in the U.S. is used on the key pad for a phone because it is at the extreme ends of the key pad and therefore unlikely to be pressed by accident. The same logic occurs in Morse.

Prior to using SOS, ships at sea used CQD which means “Call to Quarters – Danger”.

Q. Where did the abbreviated codes come from and why are they used?

A. Morse code can be laborious to send and slow when using a hand pump style of key. Therefore various code systems were used by operators to shorten the time it took to send messages. In the early days of Morse code on ships there was a book published which has these codes in it. Of those short version codes CQ, 73′s 88′s and a few other number codes are the only ones remaining.

In the case of CQ, it is simply an invitation for any wireless operator who can receive the call to answer. There are variants of CQ followed by the callsign such as “CQ CQ CQ G4ZQM DE G0TMH ” which is a specific request for a station to reply ( In the example radio station G0TMH is calling G4ZQM the DE means ‘from’). CQDX requests a long distance communication. (All of these codes are used by radio hams today using Morse).

CQD was the internationally recognised call requesting any station to respond to a distress call (one assumes the D of CQD stands for “distress”).

Other codes and cyphers existed such as the number codes 73′s and 88′s which were used by radio operators to shorten messages for passengers on ships who regularly said the same thing such as “Best wishes” (73) and “Love and kisses” (88). Most of these number codes have been lost in time and there are no copies of the radio officers code books available. It is also likely that each shipping company had its own short version codes to encrypt traffic from other companies and ships listening in.

Q. What are the advantages of using Morse code?

A. Morse code provides a letter-based method of communication by means of any type of signal that can be switched on and off … light, sound, etc. As such, it can accommodate messages in any language that uses the familiar Roman (English) alphabet. While using the simplest possible transmitting and receiving equipment, it is highly immune to noise, and can succeed over very noisy ‘channels’.

Q. What is the difference between American, Continental and International Morse?

A. Samuel Morse’s original code was designed for the landline telegraph service. It worked well with the mechanical sounders heard in the telegraph stations. However, with use, some characters were changed by various users in various countries.

In 1848 Germany created a standard which eliminated the long spaces and long dashes. The new standard also changed the code for the numerical characters. This modified version of the Morse code was accepted in 1865 throughout Europe and became known as Continental Morse. Later, as Continental Morse was accepted for use around the world, it became known as International Morse. The original version of Morse code became known as American Morse.

In 1912 at the Radio Telegraphic Convention meeting in London, it was decided that all radio signals would be sent using International Morse. Thus the confusion of various operators inter-mixing the two codes was eliminated. American Morse remained the standard for U.S. landline telegraph companies, as it could be sent about 5% faster than International Morse.

American Morse was also commonly used for domestic radio traffic on the Great Lakes and along the coasts. International Morse was used on ocean-going vessels. Many shipboard operators were skilled at using both versions of the Morse code.

Today, American Morse is nearly extinct. It was last used by the railroads. Some Civil War re-enactments use American Morse for historical accuracy.


American Morse

International Morse Code