Jan 19, 2026
posts
Jan 19 8:40 PM #16 2 min The Chord I Could Finally Hold
Chord Spectrogram Relief TilesTwo out of three chord guesses right—by touch alone. My fingers apparently know things my ears don't.
Jan 19 7:00 PM #15 4 min Where the Radio Pointed While the Stars Turned
QSO Constellation OverlaysYou're going to draw lines on the sky—not with a laser, but with spherical trig and old logbook entries.
code-a-day
Mapping Ham Radio Contacts to the Stars
Spatial Indexing with Quadtrees 🔗 QSO Constellation OverlaysHow amateur radio operators efficiently overlay QSO locations on constellation maps using recursive space subdivision.
games
🎮 Touch the Chord Music identification quiz — hear a chord, read its spectrogram relief tile, and tap the correct name. 12 rounds of major, minor, diminished & augmented chords.
🎮 Arc Logger QSO Constellation Overlays — memorize star colors by frequency band, then draw arcs connecting matching pairs. Overlapping arcs cost points. 6 rounds of increasing difficulty.