From the Mind of Trevor Stone

Amateur radio operators are probably the only folks who regularly use Morse code in the 21st Century. Long distance communication today generally happens by voice or digital data; and often voice encoded as data. Militaries stopped training radio operators in Morse code. The final US telegram was sent in 2006; in India it was 2013. Britain's service ended in 1981. Those articles report that in 1920, Western Union charged 5 cents per word (when a nickel was worth something) and the Royal Post Office charged a penny per word, with an exchange rate of about 3 pence per nickel. Back when phone plans didn't just bundle unlimited SMS, it seemed 5 cents (at 2005 value) was the going rate… with space to fit about 20 short words. And anyone with access to the Internet has been able to send thousands of words for free via e-mail for more than three decades.

A couple things keep the dits and dahs of Morse code flowing on the amateur radio airwaves. One is tradition: it's a hobby stereotypically practiced by old dudes, and they had to demonstrate Morse code proficiency to get their license (prior to 2007), so there's a comfortable feeling to it, even if they're not banging out the QSOs with a Vibroplex bug on a Hallicrafters solid-state transmitter.

But it's not just nostalgia that keeps Morse code alive. There are practical advantages to Morse and Continuous Wave. CW puts all the transmitter's power into a narrow bandwidth which is either on or off, and the duration of those emissions create the code pattern. This makes CW ideally suited for low-power long-distance transmissions, also known as "weak signal". While clear-channel AM broadcasters used 50 kilowatts to carry Art Bell's voice across the Great Plains, Art as ham operator W6OBB could have conveyed a message just as far with a one or two watt CW signal. It would've taken a lot longer to relay the caller's story about an alien abduction, though. The AM signal spends half its power on the carrier wave, and the other half is split between two identical modulated waves above and below the carrier frequency, spreading out 5 kilohertz in each direction. The CW signal fits in 100 hertz or so, so it's more like a laser pointer than like a lightbulb.

That narrow bandwidth also means the receiver can listen with a really tight filter. Lower-frequency radio bands often have a lot of static; for an example listen to your AM radio during a summer night with a lot of thunderstorms, or listen to the 75 meter band almost any night of the year. (If you enjoy eavesdropping on colorful characters, the latter offers hours of free entertainment.) The wider the bandwidth of the receiver, the more atmospheric static you'll get in your audio signal and the harder it will be to hear what anyone's saying. But with a CW filter that's only a few hundred hertz wide, you can pick out enough of the dits and dahs to understand the transmission.

Finally, the technology for a CW radio transmitter is about as simple as you can get. A straight key or an iambic paddle closes an electric circuit to send a signal; releasing the lever opens the circuit to stop transmitting. The rest of the circuitry doesn't need to modulate or demodulate the signal, so a student or tinkerer could conceivably start from scratch and end up with a working radio. The cheapest CW transceiver kit I've seen is $15 (but it doesn't have the ability to change frequency). And any mechanism you can think of to complete a circuit can be made into a CW key. (I'm interested in trying the QLF sewing machine pedal, and the nail clipper key should be quite portable.)

I realized the value of CW when I was preparing for a trip to Hawaii. It took a lot of work to pull off ten single-sideband (2.5 kHz bandwidth) contacts in two hours with a 45-watt amplifier, since it's 2500 miles to California. I realized I could probably have lightened my load and still pulled off the activation with a 5 or 10 watt radio and morse code. I even got a light-weight paddle and spent time on the airplane with a Morse code tutor. I didn't end up sending any CW from the island, which is probably just as well… I might have been able to copy at five words per minute.

Last year I set a Parks on the Air goal of making at least one CW contact with each activation. I definitely didn't hit the "every activation" goal (particularly in the fall and winter months when I preferred keeping my gloves on to hit the mic's PTT button), but I did manage to make over 133 CW contacts from more than 20 parks. Sunday evening POTA activations also proved a good opportunity to participate in the weekly K1USN SST slow-speed CW "contest". I was pretty reliant on a decoder app, but I could reliably send at 12 to 15 WPM and a healthy Farnsworth spacing. I can recognize my own WT0RJ callsign by ear with no problem, and CQ SST stands out quite clearly. Visually following the app makes it hard for me to also focus on listening, so recently I've taken to tuning to a station calling CQ, getting their callsign from the app, and then waiting until I can pick out all the characters by ear before responding.

I've also recently gotten a chance to be hands-on with the hardware side. Last year at a hamfest I bought both a Brown Bros CTL-B combined paddle and straight-key crafted in the late 1970s (photo) and a light-weight 3D printed paddle kit made my a local ham. The former doesn't have an output jack, just screw terminals. This February I finally got around to taking it to my office's maker space to wrap three wires around the terminals and inside a 3.5mm jack. The hefty base and hard plastic paddles make for a noticeably different feel when operating. I need to experiment with the screws to find my ideal motion range, but it definitely feels more precise. A few weeks ago I also finally got around to constructing the 3D printed kit. I almost screwed it up by soldering too long a tip on the short wires, but I managed to route everything in the box without impediment. For a base I picked up a very thin sheet of steel which seems to stay with half sitting under a radio, so I can stick the magnetic feet to it and keep the paddle from sliding all over the place while I swipe left and right to call CQ.

Now I've got all the technology, I just need to make time for dedicated practice…