Spectrum Painter
Draw images on a waterfall
What it does
SimpleThis is a piece of radio art. It sends a special signal that, when someone looks at it on a 'waterfall' display (the scrolling picture of the radio spectrum), shows a picture or word instead of a plain blob. You could paint your name, a smiley face, or a little drawing into the radio spectrum.
It's purely for fun and learning — a memorable way to see that a waterfall is really a map of energy across frequency and time, which you can deliberately shape.
How it works
SimpleA waterfall screen shows strong signals as bright dots. Spectrum Painter turns a picture into a signal where the bright and dark parts land in exactly the right spots, so when the waterfall draws them, they form your image line by line — like an inkjet printer that prints with radio energy.
How to use it, step by step
Simple- Put an image on the memory card.
- Open 'Spectrum Painter' and pick it.
- Choose an allowed channel.
- Transmit, and watch it appear on a waterfall display.
Examples
Paint your callsign so it appears as readable text on a spectrogram.
Hide a short message in the spectrum as a capture-the-flag style puzzle.
Try a wide vs narrow bandwidth and see how it changes the image's resolution.
Tips & things to try
- High-contrast, simple images 'paint' the clearest — fine detail blurs.
- The viewer needs matching FFT/bandwidth settings to see it crisply.
- It's the most artistic way to understand what a waterfall really shows.