If you’ve learned the Morse code for letters, you know it’s a system of dot and dash symbols. But did you know that there are also patterns for numbers? This guide explains them in full.
The ten-digit pattern
Each digit from 0 to 9 has its own sequence of dots and dashes. These sequences can be used individually or together to make multi-digit numbers. Here are all of the five-signal (dot/dash) codes:
Digit 1 = · – – – –
Digit 2 = · · – – –
Digit 3 = · · · – –
Digit 4 = · · · · –
Digit 5 = · · · · ·
Digit 6 = – · · · ·
Digit 7 = – – · · ·
Digit 8 = – – – · ·
Digit 9 = – – – – ·
Digit 0 = – – – – –
Multi-digit numbers are written as a sequence of five-signal codes. Every digit is exactly five signals long, though some start with a dot and others with a dash.
For example, here’s how to represent the number 10:
Digit 1 = · – – – –
Digit 0 = – – – – –
Number 10 = · – – – – / – – – – –
You’ll notice that digits 1 through 5 begin with a dot, followed by an increasing number of dashes. Digits 6 through 9 follow the same logic, except that they begin with a dash and end with a dot. Digit 0 follows the opposite rule: it’s a reverse of the ratio between dots and dashes.
That logic isn’t arbitrary. In fact, the entire set of ten digit codes can be considered a predictable symmetric set. You’ll probably never memorize the individual patterns, but if you understand the mirror-logic principle, you won’t need to.
ITU-R spacing rules
In addition to the patterns, you’ll need to understand the ITU-R spacing rules. That includes the timing between signals, between each digit, and between numeric groups.
These rules are found in the International Telecommunication Union’s Recommendations (ITU-R). Specifically, the M.1677-1 recommendation spells out these timings in terms of units. A unit is the time interval between the start of one signal and the next. So the space between two dots would be one unit, and the space between a dot and a dash would be two units, etc.
Here are the recommended timing rules:
There should be no gap between the symbols within the same character.
One unit of silence should occur between the symbols of one character.
Three units of silence should separate characters in the same group.
Seven units of silence should be observed between words.
Because of this spacing, you’ll often see slashes separating the different digits. The slash marks indicate where the inter-character boundary occurs. For instance, the sequence · – – – – / · · – – – / · · · – – represents the digits 1, 2, and 3.
The most common confusion
It might seem odd to consider numbers, which are essentially combinations of dots and dashes, as having their own unique patterns. However, it’s actually easier than learning the letter combinations.
In fact, the most confusing point may be learning the difference between H and 5. If you look at both, you’ll notice that they’re practically identical — four dots for H, and five dots for 5. Because of that, many people mistakenly think the two are the same. They’re not, however. To avoid making this mistake, it’s a good idea to learn the two as contrast pairs.
What’s more, numbers were actually the foundation of Morse’s original telegraph system, rather than just a later addition to it. In 1837, Samuel Morse designed the system specifically to transmit only numerals. The telegraph system operated by sending electric pulses along wires to transmit information. Each pulse was either a short “dot” or a longer “dash.”
In those days, telegraph operators didn’t know what the messages meant. Instead, they simply transmitted the encoded messages, which could then be decoded using a codebook. There was even a separate codebook for decoding the meaning of each number group. Today, we don’t use Morse code in the same way; instead, it’s used by radio amateurs (also known as “ham radio operators”) to send messages via amateur radio stations.
How to become fluent in Morse code
Like any skill, fluency in Morse code takes practice. If you’re looking to master it, you should approach your training like you would learning any new language.
First, you should start with numbers before advancing to mixed letter-and-number messages. Why? Well, when I first started learning Morse code, my instructor had me encode the birth year, today’s date, and a couple of other personal details. I already knew the correct answer, so I was able to quickly test myself and find out whether I’d mastered the technique.
After mastering the numbers, you should move on to combining letters and numbers together. Once you’ve done that, you can move on to combined letter-and-number messages.
Radio operators send ‘599’ in Morse code to signal that the signal received was perfect.
To speed up your learning process, try listening to a recording and repeating after it. This trains your ears to pick up the rhythms of the code and recognize the patterns.
Finally, once you feel comfortable working with the code, it’s time to step things up and try sending it out yourself. This is where it gets tricky. After all, it’s easy to sit back and listen to a message and think you understand it. It’s harder to work through a message and produce it yourself.
Why ear training matters
When I first picked up a transmitter and began learning Morse code, I assumed that reading Morse code was similar to reading it visually, and that I could train myself by looking at charts. My instructor corrected me immediately: professional CW operators read entirely by sound — there is no chart, and no screen. All of the training was done by ear.
Professional radio operators have demonstrated that Morse code is capable of being read and processed at speeds exceeding 84 WPM (words per minute), according to Military.com. The average experienced operator can manage about 30 to 35 WPM, however. That level of speed is possible only when the code is recognized and processed by the ear, not by visual decoding.