Morse code (CW)

Text sent as short and long beeps (dits and dahs) by switching a single tone on and off. It's the oldest digital mode on the air, and still one of the most popular.

My life list

ModeMorse code

FamilyKeyed carrier

Audio example12 s

Morse code sounds like a single clear beep switching on and off in short and long pieces, grouped into letters and words with brief silences between them.

What does it sound like?

Plate 36Keyed carrier

A clean, steady beep turning on and off in a rhythm, like a very fast telegraph.

0 Hz1,0002,0003,000 Hz

Waterfall picture of Morse code (CW): pitch runs left to right, time runs downward

12-second example. Morse code made by Cohera: the traditional test letters VVV, a general call (CQ) and a practice sentence at 18 words per minute.

Field marksOne tone switched on and offSpeed about 5-40 words per minuteVery narrow: about 100 Hz or less

Hear it, step by step

This Morse clip is one 700 Hz tone switched on and off to spell VVV VVV CQ CQ THE, the start of a practice sentence.

Waterfall of this example: pitch left to right from 0 to 3,000 Hz, time running down

Tap a step to hear that moment. The box shows where it is on the waterfall.

Make your own: type a message and hear it as Morse code (CW) in the Signal Maker.

Who uses it?

Amateur radio operators worldwide, beacons, some navigation aids and a few utility stations.

Where and when can I hear it?

All over the ham bands, most often near the bottom of each band (for example, 7.000-7.060 and 14.000-14.070 MHz). The ARRL's station W1AW sends Morse practice and bulletins on a published schedule.

Hear it live

University of Twente WebSDR (Enschede, the Netherlands) · 14,100 kHz CW
Around the clock. Eighteen beacons take turns: each sends its call sign in Morse and four dashes, 10 seconds per beacon, and the cycle repeats every 3 minutes. You hear only the beacons whose signal reaches the receiver.
Northern Utah WebSDR #2 (Northern Utah, USA) · 14,099 kHz USB
Around the clock. Eighteen beacons take turns: each sends its call sign in Morse and four dashes, 10 seconds per beacon, and the cycle repeats every 3 minutes. You hear only the beacons whose signal reaches the receiver. Tuned 1 kHz low in USB so the beacons' Morse is heard as a tone.
Northern Utah WebSDR #1 (Northern Utah, USA) · 7,046.5 kHz USB
Weekdays (ARRL schedule, US Eastern time): code practice at 4, 7 and 10 p.m.; Morse bulletins at 5, 8 and 11 p.m. W1AW is in Connecticut, so it may be weak or absent at this receiver. Tuned 1 kHz below 7.0475 MHz in USB so the Morse is heard as a tone.

These are free public receivers run by other people; we only link to them. You'll hear the signal only if it's on the air right now and conditions carry it to that receiver, so if it's quiet, try another time. Links last reviewed 2026-09-28.

The science

The transmitter sends a single radio frequency and simply turns it on and off. The official emission code for Morse sent this way is A1A: an amplitude-keyed signal carrying telegraphy meant to be read by ear. The timing is fixed by the ITU's International Morse code standard: a dash lasts three dots, the gap inside a letter is one dot, the gap between letters is three dots, and the gap between words is seven dots. Because only an on-or-off state is sent, a Morse signal needs only about 150 Hz of radio spectrum, far narrower than a voice signal. A receiver makes the keyed carrier audible by mixing it with a signal from its own oscillator, which produces a beep whose pitch depends on how it is tuned.

Why use it?

Its tiny bandwidth lets a receiver use a very narrow filter that shuts out most of the surrounding noise, so Morse often gets through when voice cannot. The equipment can be very simple, and a trained human ear can pick a faint, fading signal out of static. Operators also value that it needs no computer at all, only a key, a transmitter and a listener.

Lore

On May 24, 1844, Samuel Morse sent the message "What hath God wrought" by telegraph from the U.S. Capitol to his partner Alfred Vail in Baltimore. The code has kept evolving since then: the current ITU standard even includes a Morse character for the @ sign used in email addresses.

What do the decoded parts mean?

Text: The letters and numbers being sent. Hams use many abbreviations: CQ means 'calling anyone', DE means 'from', 73 means 'best regards', and RST numbers such as 599 are signal reports.

Easily confused with

Radioteletype (RTTY): RTTY uses two tones and never goes silent between letters
Time signal station: a time station ticks every second, skipping one or two each minute

How to recognize it

Listen for one steady pitch that is either on or off. There is no second note, no warble and no hiss inside the tone itself. The short sounds (dits) and long sounds (dahs) are in a fixed ratio of about one to three, and the gaps tell you where letters and words end: a short gap inside a letter, a longer one between letters, and a longer one still between words.

The pitch you hear is set by your own receiver, not by the sender. Most operators tune so the tone sits somewhere around 500 to 800 Hz, which is why two people listening to the same station may hear it at different pitches.

Easily confused with:

Radio beacons and navigation aids: also Morse, but they repeat the same short identifier (often two or three letters) over and over.
RTTY: two tones that alternate with no silences, rather than one tone that stops and starts.
An unmodulated carrier: a single tone that never switches off.

Where and when to hear it

On the ham bands, Morse gathers at the low end of each band. Evenings on 40 meters (7.000-7.060 MHz) and daytime on 20 meters (14.000-14.070 MHz) are reliable places to start. Contest weekends fill these segments wall to wall.

For a known, readable signal, the ARRL's station W1AW in Connecticut sends code practice and bulletins on a published schedule, on frequencies including 3.5815, 7.0475 and 14.0475 MHz. Slow practice runs from 5 to 15 words per minute, fast practice from 35 down to 10, and bulletins go out at 18 words per minute. Because the text of many practice sessions is published, it is a good way to check your own copying.

The Northern California DX Foundation and IARU run a worldwide chain of beacons on 14.100, 18.110, 21.150, 24.930 and 28.200 MHz. Each beacon sends its call sign in Morse in a fixed 10-second slot, so a whole cycle takes three minutes, and hearing which ones come through tells you which parts of the world a band is reaching.

A little history

Samuel Morse and Alfred Vail developed their telegraph code in the 1830s and 1840s; the famous message "What hath God wrought" crossed the line from Washington to Baltimore in May 1844. The version used on the radio today is the International Morse Code, which differs from the original American code in several letters.

Radio took Morse wireless at the turn of the twentieth century, and for most of that century it carried shipping, aviation and military traffic. Ships formally stopped relying on it when the Global Maritime Distress and Safety System reached full implementation on February 1, 1999. In the United States, the Federal Communications Commission dropped Morse testing for all amateur licenses in February 2007, yet it remains one of the most popular modes on the ham bands, because it gets through with simple equipment and weak signals.

Common questions

Is it legal to listen to Morse code on the radio?

Yes. Amateur and beacon Morse is sent in the open, and anyone may receive it. Listening needs no license; only transmitting does.

Why do Morse signals sound like different pitches?

Morse is sent as a plain carrier switched on and off. Your receiver turns that carrier into an audible tone, and the pitch depends on exactly how you tune. Move the dial slightly and the note rises or falls.

How fast is Morse code sent?

Speed is counted in words per minute, using a standard word ("PARIS") as the yardstick. Beginners start around 5 to 15 words per minute; everyday ham conversations run about 18 to 25; experts and contesters often go past 35.

Can I decode Morse code on a computer?

Yes. Free desktop programs such as fldigi can turn clean Morse into text, and many operators learn to copy it by ear. Machines struggle more than trained people with fading, interference and uneven hand-sent timing.