In 1990 I programmed an old and obsolete Commodore Vic-20 computer to decode Morse Code emanating from a shortwave radio and display the text onto a CRT television set. The radio had a very simple electromagnetic relay interface to the computer's joystick port fire button, such that when the transmissions were being received (and the signal was strong enough), the audio output (passed through a simple beat frequency oscillator (BFO)) would be amplified through a step-up transformer. The transformer output would supply sufficient voltage to the small 9-volt relay, causing the switch to turn on and off along with the code. The computer code took me three days to work out and several weeks to modify. The decoder was pretty decent, decoding reports in real-time about sunspot numbers, the space shuttle, and icebergs (and growlers) off of the coast of Newfoundland. The decoder actually spelled "NEWFOUNDLAND" correctly!
Just over 150 years previously, more specifically in 1836, Samuel Morse began the code that would bear his name. He needed a code that could be used with the new telegraph system being constructed in the United States. The early telegraph was an electromagnet that would emit clicks for specific amounts of time to discern between the "dots" (·) and "dashes" (-) that a letter, number, or punctuation symbol, would be comprised of. A letter could have a single dot (or dash), two, three, or four individual characters comprising of dots and dashes. A letter used more often in sentences, such as "E" (·) or "T" (-) would have one or two characters. On the other hand, characters used least often, such as the letter "Q" (- - · -) or "Z" (- - · ·) would have four characters. A number would have 5 characters. Punctuation would have 6 characters. The punctuation period is denoted by " · - · - · - ". Figure 1 shows the international Morse Code for letters and numbers.
Figure 1: International Morse Code
Voice was not transmitted over long distances until the telephone was invented in the late 19th century. Throughout much of the 19th century (and a small part of the 20th), long-distance communications was only comprised of dots and dashes to be coded and decoded on a regular basis. The earliest wireless transmitters and receivers used Morse Code since voice transmission was not possible until the 1920's. The dots and dashes were easy to use and relatively easy to decode because Morse was designed to be decoded by human beings and not machines.
Morse Code was used extensively throughout both World Wars and up to the early 1990s (when I created my Morse decoder). Unfortunately, my "invention" was created at the tail end of a long dominance in communications history. Significant advances in technology throughout the 1980's and 1990's, including more sophisticated computer systems, electronic mail (e-mail), the Internet, cell phones, text messaging, GPS navigation, etc. were too much competition for a code that was originally designed for electromagnetic switches connected by above-ground wires on telegraph poles.
When the U.S. Navy discontinued its use of Morse Code in the mid-1990's, I, as many others, thought that the code would be mentioned only as a historical topic of interest rather than a code that would still be relevant in today's ever-expanding communications infrastructure. However, one advantage that Morse Code has over all other means of electronic communication is that it is extremely simple to use and transmit over wire or over the airwaves. Morse Code is only a series of 0's and 1's in which a "1" is a character and a "0" is not. All that has to be remembered is that a dot and dash have different time durations (a dash is longer than a dot) and that a "0" duration between letters is less than a "0" duration between sentences. Most of the efforts I made in programming my Morse decoder had involved training the computer to interpret the code and to teach it the alphabet, numbers and punctuation and to tell it the timings of each, depending on how fast the code was being transmitted, normally referred to as "words per minute" (wpm). I even created an automatic speed determination system, which worked well, before I discontinued the decoder's use around 1993.
I did not think much about Morse Code as I completed my undergraduate studies, when I began my career in space surveillance (satellite tracking), or during the fist decade of the 21st century. However, when I began my graduate studies at the Royal Military College of Canada (RMCC), I was reintroduced to the exciting world of amateur radio, this time using VHF/UHF transceivers. I could listen to a whole new world of amateur repeaters, marine radio, and especially a new method of tracking satellites: by listening to them transmitting messages back to the Earth. A number of these satellites, called cubesats, were using a familiar code that I had not heard since the early 1990's: Morse Code! I could not believe my ears. How could a sophisticated piece of equipment that was launched into space be using such an old and antiquated communications code?
Cubesats are designed and constructed by high school and university students. The satellites are perfect tools to teach them about the complexities of requirements management, trade-off analysis, budgets (technical and financial) and launch logistics. They are also excellent tools to teach them about communications. Figure 2 shows the TISat-1 1U cubesat (call sign HB9DE) from Switzerland. The cubesat was developed by the students and staff of the University of Applied Sciences of Southern Switzerland, Department of Technology and Innovation (SUPSI-DTI). The cubesat regularly identified itself via Morse Code on both VHF and UHF frequencies.
Figure 2: The TISat 1U Cubesat
Cubesats are small when compared to the satellites that were launched twenty years ago. The smallest ones are 10x10x10cm (a small cube) (a 1U cubesat) and the largest ones are 10x10x30cm (a 3U cubesat). There is not much room in them to pack in sophisticated communications equipment. For most of these satellites, the simplest solutions are the best ones. This important point brings us back to Morse Code: a very simple code. Many cubesat designers consider the amateur radio community, many of which know Morse Code (also known as "CW" because it only requires a continuous wave transmitter). Immediately following a cubesat's release from the launch vehicle (or the International Space Station), it is seldom above the owner's local horizon. It is better the know whether the cubesat is alive or not as soon as possible so that its status can quickly be ascertained. The amateur radio community (HAMs) can listen for the satellite's transmissions before the owners can. Since many amateur radio enthusiasts know Morse Code (CW), they can listen to the cubesat's telemetry and decode it without any additional tools other than their ears, a pencil and some paper. Once the telemetry is received, the HAM can then alert the cubesat owners via e-mail or social media.
Cubesats also transmit digital packets and can be used as FM and SSB (single sideband) voice repeaters, but since they cannot always be heard well because of their altitude and distance from the receiver, a series of dots and dashes is far more discernable than a weak voice of digital transmission. This gives Morse Code the edge with respect to legibility over larger distances and lower elevations above the local horizon.
The VE3RMC amateur radio satellite communications station at RMCC has received a total of 70 cubesats and small satellites since early 2012. Of this number, 35 (half) of them use Morse Code on a daily basis to convey status and health telemetry to the Earth so that HAM radio operators can decode it and inform the owners of any problems. In many cases, the Morse Code conveys hexadecimal characters (0 to 9 and A to F) that need to be translated to decimal format. Today, simple computer software can perform both the Morse decoding and the hexadecimal to decimal translations.
Twenty-five years after I created my first Morse decoder with a Commodore Vic-20 and a short-wave radio, I created another Morse decoder using a much better computer running Windows 7, Matrix Laboratory (MATLAB), and recordings from the VE3RMC station to decode telemetry from the Japanese Prism (Hitomi) satellite. This software does not decode the real-time code, but reads digital audio recordings of the transmissions and automatically extracts the dots and dashes. If required, the audio file can be post-processed to remove static and other background noise so that the software can decode even the weakest signals.
Today's amateur radio enthusiasts are also transmitting Morse Code (CW) to satellites so that they can cover a wider area. I normally hear them using the old Oscar-7 (AO-07) and the newer JAS-2 (FO-29) satellites and I can easily identify them from their call signs that I can decode from the recordings. Recordings that I have made of cubesat transmissions with the VE3RMC amateur radio station are available on my "Satellites on Radio" page.
Morse Code is certainly not dead for the simple reason that satellites, designed, constructed, and operated by the next generation of satellite engineers, are transmitting the familiar dots and dashes right now as you read this. Since the cubesats are the present and future of artificial satellite technology, Morse Code will yet again be coming along for the ride.
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The Resurrection of Morse Code Was Last Modified On May 25, 2015