Teaching the Wind to Sign My Name in Dits and Dahs

Dear version of me who hasn’t tried this yet,

You are going to stand at your workbench with a bundle of aluminium tubes and a chart of Morse timings, and you are going to think you understand what you’re doing. You don’t. Not yet. But that’s fine.

Here is what nobody tells you about encoding a callsign in wind: the code is not in the tubes. The code is in the gaps. You will space your first set of chimes evenly because it looks elegant, because symmetry is tidy, because your brain wants the kind of order that photographs well. The result will look like a windchime and sound like noise. The 1-3-7 ratio—dit, dah, intra-character gap, letter gap, word gap—is not a guideline. It is ITU-R M.1677. It is the law. The silence is half the message.

The tubes themselves are easier than you expect. Aluminium 6061-T6, a hacksaw, and a caliper. The pitch follows an inverse-square relationship with length: double the tube, drop the pitch by two octaves, not one. Your ear will mislead you here. Actually, your ear will mislead you in several places. Tubular chimes produce something called a “strike tone,” which is a pitch your brain constructs from overtone ratios. The note you hear is technically a phantom, an octave below the fourth vibrational mode. You are not tuning notes; you are tuning the illusion of notes. This bothered me for about an hour before I decided it was poetic.

Pick a pentatonic scale. You will want to be clever—you will want a minor key, maybe, or some chromatic tension to match the mood of your callsign. Resist. Wind is aleatoric. Chance-based. The tubes will strike in combinations you cannot predict, and if your intervals punish each other, you will regret it every time a gust bunches three dits into a single clang. Pentatonic forgives. Pentatonic lets the randomness sound like music instead of a dropped toolkit.

The mallet matters more than I expected. I 3D-printed a central striker with a flexible PLA neck, and the first version was too heavy. Every strike sounded like a church announcing vespers. The second version was too light—the tubes barely whispered, even in a decent breeze. The third version works. It swings, it returns, it doesn’t stick. You will find your own third version. Budget for two failures.

When you finish the embroidery project next week—the Morse Waypoint Flightpath Embroidery where you stitch CYBW in copper thread and forget to leave letter gaps—you will think you have learned this lesson. You will not have learned this lesson. The hand wants momentum. The stitch wants to continue. The gap is an interruption, and interruptions are hard to make intentional. The same problem will reappear here, in three dimensions, when you’re drilling mounting holes and your arm wants to space them evenly instead of spacing them correctly.

A historical note that will make you smile: Roman wind chimes—tintinnabula—were hung with bronze phalluses to ward off the evil eye. The British Museum has examples. The protective function of chimes predates the decorative one by two thousand years. Your callsign mobile is joining a lineage of objects designed to make wind carry meaning, and some of those meanings were extremely literal about what they were protecting.

Alfred Vail counted the moveable type in a New Jersey printer’s shop in 1840 to design the letter frequencies for Morse code. E is a single dit because E was the most common letter in the type cases. When you encode VE6SLP, you are working with a 180-year-old optimization based on physical metal inventory. The tubes on your porch are a distant echo of Vail’s counting.

You will hang the finished chime on a windless evening, of course. This is how these things go. But the first real breeze—three days later, maybe, while you’re doing something else entirely—will catch you off guard. You will hear it from inside. V, E, 6, S, L, P. Not perfectly. Not every letter clean. But readable. Your callsign, in the air, signed by the weather.

It is a small, stubborn transmitter that runs on patience instead of power.

Start with the timing chart. Measure twice. Leave the gaps.