Adventures with Morse Code

Adventures with Morse Code

Author: Onno (VK6FLAB) July 15, 2023 Duration: 6:11
Foundations of Amateur Radio

If you've ever looked at Morse Code, you might be forgiven if you conclude that it appears to be a less than ideal way of getting information from point A to point B. The idea is simple, based on a set of rules, you translate characters, one at a time, into a series of dits and dahs, each spaced apart according to the separation between each element, each character and each word.

The other day I came across a statement that asserted that you could send Morse faster than binary encoded ASCII letters. If you're not sure what that means, there are many different ways to encode information. In Morse, the letter "e" is the first character, represented by "dit", the letter "t" is the second character, represented by "dah". In ASCII, the American Standard Code for Information Interchange, the letter "e" is the 69th character, represented by 100 0101. The letter "t" is number 84 on the list, represented by 101 0100.

A couple of things to observe. The order of the characters between Morse and ASCII are not the same. That doesn't really matter, as long as both the sender and receiver agree that they're using the same list. Another thing to notice is that in Morse, letters are encoded using dits and dahs and appropriate spacing. In ASCII, or technically, binary coded ASCII, the letters are encoded using zero and one.

I'll also mention that there are plenty of other ways to encode information, EBCDIC or Extended Binary Coded Decimal Interchange Code was defined by IBM for its mainframe and mid-range computers. It's still in use today. In EBCDIC, the letter "e" is 133 and the letter "t" is 163. It was based around punched cards to ensure that hole punches were not too close together. It was designed for global use and can, for example, support Chinese, Japanese, Korean and Greek. Another encoding you might have heard of is UTF-16, which supports over a million different characters including all the emojis in use today.

Before I continue, I must make a detour past the ITU or the International Telecommunications Union. The ITU has a standard, called "Recommendation M.1677-1", approved on the 3rd of October 2009, which defines International Morse code. I'm making that point because I'm going to dig deeper into Morse and it helps if we're talking about the same version of Morse. I have talked about many versions of Morse before, so I'll leave that alone, but I will point out a couple of things.

The ITU defines 56 unique Morse sequences or characters. The obvious ones are the letters of the alphabet, the digits and several other characters like parentheses, quotes, question mark, full-stop, and comma, including the symbol in the middle of an email address, which it calls the "commercial at symbol" with a footnote telling us that the French General Committee on Terminology approved the term "arobase" in December 2002, but it seems that seven years isn't enough time to convince the ITU to update its own standard, mind you, the rest of the world, well, the English speaking part, calls it "at", the letter "a" with a circle around it, as in my email address, cq@vk6flab.com.

Another thing to note is that this standard is only available in English, Arabic, Chinese, French and Russian, so I'm not sure what the Spanish, Hindi, Portuguese, Bengali and Japanese communities, who represent a similar population size do for their Morse definitions. It's interesting to note that as part of its commitment to multilingualism, the ITU actually defines six official languages. Specifically, the "Spanish" version of the standard appears to be missing.

There's other curious things. For example, the standard defines a special character called "accented e", though it doesn't describe which accent, given that there are four variants in French alone, I found at least seven versions and it completely ignores accents on the i, the c, the o, special character combinations like "sz" in German and "ij" in Dutch. This isn't to throw shade on Morse, it's to point out that it's an approximation of a language with odd variations. I'm also going to ignore capitalisation. In Morse there's none and in ASCII, there are definitions for both, capitalised and not.

In addition to things you write in a message, there's also control codes. The ITU defines six specific Morse control codes. Things like "Understood", "Wait", and "Error". ASCII has those too. The first 31 codes in ASCII are reserved for controls like "linefeed", "carriage return", and "escape".

There are other oddities. The ITU specifies that the control code "Invitation to transmit" is symbolised by dah-dit-dah. If you're familiar with Morse, you'll know that this is the same as the letter "k". The specification says that multiplication is dah-dit-dit-dah, which is the same as "x". There's also rules on how to signify percentages and fractions using dah-dit-dit-dit-dit-dah, the hyphen, as a separator.

At this point I haven't even gotten close to exploring efficiency, but my curiosity is in overdrive. Is Morse really optimised for English, or are there other forces at work? I'm already digging.

I'm Onno VK6FLAB


For anyone curious about the crackle of a distant voice emerging from the static or the thrill of making a contact across the globe using nothing but radio waves, Foundations of Amateur Radio offers a friendly, steady guide. Hosted by Onno (VK6FLAB) from Australia, this long-running podcast acts as a companion for newcomers navigating the initial, often overwhelming, steps into this vast hobby. Each episode deliberately unpacks a single facet of amateur radio, breaking down technical concepts, equipment, and operating practices into digestible pieces. You'll hear practical advice on how to get started, find your place within the global community, and discover which of the hobby's countless avenues-from building antennas to satellite communication or emergency service-might spark your passion. It’s not about dry theory; it’s about demystifying the process and sharing the genuine rewards that keep enthusiasts engaged for a lifetime. Having evolved from its earlier incarnation in 2011, this podcast builds from the ground up, week by week, creating a solid resource that grows with you. Tune in for a down-to-earth conversation that makes the airwaves feel a little more accessible and a lot more inviting.
Author: Language: English Episodes: 579

Foundations of Amateur Radio
Podcast Episodes
Amateur Radio has literally changed my world view [not-audio_url] [/not-audio_url]

Duration: 4:14
Foundations of Amateur Radio The other day I went for a walk, I know, shock-horror, outside, daylight, nature, the whole thing, in a local national park, for the first time in too many years. Almost immediately I noticed…
How small is small? [not-audio_url] [/not-audio_url]

Duration: 8:08
Foundations of Amateur Radio I've owned a Yaesu FT-857d radio since becoming an amateur and at the time I was absolutely blown away by how much radio fits inside the box. It's smaller than most of the commercial radios I…
Bald Yak 12, getting raw data from a remote receiver [not-audio_url] [/not-audio_url]

Duration: 5:13
Foundations of Amateur Radio Over the past nine months or so I've been working on a project that I've called Bald Yak. If you're unfamiliar, the Bald Yak project aims to create a modular, bidirectional and distributed si…
Using an SDR as measuring equipment [not-audio_url] [/not-audio_url]

Duration: 5:14
Foundations of Amateur Radio The other day I stumbled on a random post by Gary N8DMT which caused me to view the world in a different way. The post outlined combining a PlutoSDR and an application called SATSAGEN to meas…
Listening to local RF via a web browser [not-audio_url] [/not-audio_url]

Duration: 4:42
Foundations of Amateur Radio Recently I discussed the idea of listening to the radio spectrum across the internet for the purposes of getting signal into your shack when radios, or in my case, antennas are causing you ch…
Decoding distant signals over the web? [not-audio_url] [/not-audio_url]

Duration: 5:49
Foundations of Amateur Radio One of the many challenges associated with being a radio amateur is actually being able to listen to weak signals. If you're like me and more than half the planet, you live in an urban area,…
What can we activate today? [not-audio_url] [/not-audio_url]

Duration: 4:28
Foundations of Amateur Radio Every single radio amateur has come to this hobby with an itch to scratch. Time and again I've seen amateurs around me pursue that particular purpose, only to come out the other end with a lo…
Using Amateur Bands for other purposes [not-audio_url] [/not-audio_url]

Duration: 10:59
Foundations of Amateur Radio Recently I came across a series of strident posts about the injustice associated with a non-amateur service using the 70cm band. Complete with links to discussions, spectrum plots, angst and…
There's promotion .. and then there's Amateur Radio [not-audio_url] [/not-audio_url]

Duration: 5:33
Foundations of Amateur Radio In the community of radio amateurs scattered around the planet we have a habit of getting together with others to have fun in whatever shape that takes. The obvious ones are HAMfests, car boo…
Decoding a signal ... [not-audio_url] [/not-audio_url]

Duration: 8:22
Foundations of Amateur Radio Recently I was given some radio data captured on the 40m band. Using a piece of software called "Universal Radio Hacker", I attempted to decode it. At the time I thought that this might be Mo…