CW
CW — or Continuous Wave — is the radio transmission mode used to send Morse code. It is one of the oldest, most efficient, and most enduring modes in amateur radio, and it is currently experiencing a remarkable renaissance among operators of all experience levels.
What is Morse Code?
Morse code is a method of encoding text as sequences of short signals (dots, or dits) and long signals (dashes, or dahs). Developed in the 1830s and 1840s by Samuel Morse and Alfred Vail, it became the foundation of global telecommunications — from the first telegraph lines to transatlantic cables to ship-to-shore radio.
In amateur radio, Morse code is transmitted as a continuous wave radio signal that is switched on and off to form the dots and dashes. This is why the mode is called CW. It is sometimes described as the original digital mode: structured, precise, and universally understood by operators around the world.
Here are the alpha characters:
| Letters | Numerals | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Char | Code | Char | Code | Char | Code | Char | Code | Char | Code |
| A | · − | J | · − − − | S | · · · | 0 | − − − − − | 5 | · · · · · |
| B | − · · · | K | − · − | T | − | 1 | · − − − − | 6 | − · · · · |
| C | − · − · | L | · − · · | U | · · − | 2 | · · − − − | 7 | − − · · · |
| D | − · · | M | − − | V | · · · − | 3 | · · · − − | 8 | − − − · · |
| E | · | N | − · | W | · − − | 4 | · · · · − | 9 | − − − − · |
| F | · · − · | O | − − − | X | − · · − | ||||
| G | − − · | P | · − − · | Y | − · − − | ||||
| H | · · · · | Q | − − · − | Z | − − · · | ||||
| I | · · | R | · − · | ||||||
For a full reference of Morse code characters, prosigns, and Q-codes, see the dedicated Morse Code Characters page.
CW in Amateur Radio History
From the very earliest days of amateur radio, Morse code was the primary mode of communication. Amateur operators were among the most skilled CW practitioners in the world, and the ability to send and receive Morse code at speed was a mark of genuine expertise.
For most of the 20th century, a Morse code proficiency test was a mandatory requirement for obtaining an amateur radio licence in most countries. In Australia, the requirement was tied to access to the HF bands — operators wishing to work shortwave needed to demonstrate CW competency.
In 2003, the International Telecommunication Union (ITU) removed the mandatory CW requirement for HF access, and national regulators — including Australia's ACMA — followed suit. Today, no Morse code test is required for any grade of Australian amateur radio licence.
Despite this change, CW never left the hobby. It remained a beloved operating mode, practised and celebrated by a dedicated community of operators who understood its unique advantages and satisfactions.
The CW Renaissance
Far from fading away after the licence requirement was dropped, CW has undergone a genuine revival. More operators are learning Morse code today than at any time in recent decades, driven by a combination of practical advantages and the simple joy of mastering a timeless skill.
Why CW is thriving:
- Propagation advantage — A CW signal occupies an extremely narrow bandwidth (around 150 Hz), allowing it to cut through noise and interference that would render voice modes unreadable. Contacts that are simply impossible on SSB become routine on CW.
- QRP operation — CW is the natural companion to low-power (QRP) operating. Reliable contacts across the world are regularly made with just 5 watts — or even less.
- The challenge and the reward — Learning CW is a genuine skill that takes time and practice. The sense of achievement when you make your first CW contact — or copy a callsign through the noise — is deeply satisfying.
- A welcoming community — The global CW community is known for its patience and encouragement. Slow-speed nets, practice sessions, and mentoring programmes make it easier than ever to get started.
- Contesting — CW contests such as the CQ World Wide CW and the ARRL CW Sweepstakes are among the most popular events in the amateur radio calendar.
- Simplicity — A CW station can be beautifully minimal: a transceiver, a straight key or paddle, and a wire antenna. No microphone, no audio processing, no complex setup.
CW Nets
CW nets are a great way to make your first on-air contacts and practise with other operators in a friendly, structured environment. MERC members are encouraged to check in to the CQ QRS Slow CW Net, which runs every Tuesday evening and is specifically designed for beginners and those returning to CW after a break.
For full details on net schedules, frequencies, and how to participate, see the dedicated CW Nets page.
Learning CW — Resources
Whether you are starting from scratch or brushing up on rusty skills, there are excellent free resources available. MERC members are encouraged to start with our own Morse Walker instance.
| Resource | Description |
|---|---|
| Morse Walker (OzStyle) — VK3FSK Instance ⭐ | Our own hosted instance of Morse Walker, localised with VK callsigns for realistic Australian QSO practice. The recommended starting point for MERC members. Simulates a real CW contact so you can practise in a familiar context before going on air. |
| LCWO.net — Learn CW Online | A highly regarded web-based trainer using the Koch method, which teaches characters at full speed from the start. Tracks your progress and adapts to your pace. Free to use. |
| CW Academy (CWops) | Structured, mentor-led CW courses offered free by the CW Operators Club. Available at beginner, intermediate, and advanced levels. Highly recommended for those who want guided instruction. |
| Morse Code Ninja | An extensive library of audio training files and practice resources. Excellent for building copying speed and learning to copy callsigns and common words by ear. |
| G4FON Koch CW Trainer | A popular free Windows desktop application for Koch method training. A classic tool used by many operators to reach conversational CW speeds. |
| Just Learn Morse Code | A straightforward free desktop trainer suitable for beginners. Simple interface, no fuss. |