Claude VOACAP Skill: Ask Claude About Live Ionospheric Propagation Predictions to Optimize DX

Thank you to Reid Crowe for submitting his project, "voacap-skill." This skill for Claude Code AI (a frontier LLM) lets Claude access and use the latest VOACAP ionospheric propagation data in conversations.

Instead of manually filling out a form for each prediction and analyzing the results yourself, with the voacap-skill, users can ask Claude questions like, "What's the best band to reach Tokyo from Columbus, Ohio around 0300Z in October?" and Claude will run a VOACAP prediction in the background and return an answer. Reid explains:

If you've ever used VOACAP, VOACAP Online, or watched a contest DXpedition plan its band schedule, you already know the engine underneath this: it's the same NTIA/ITS point-to-point HF prediction model that's been the industry standard for propagation forecasting since the 1980s. It takes a transmitter location, a receiver location, a month, and a sunspot number, and tells you — for every hour of the day and every frequency you care about — how reliable that circuit is likely to be.

voacap-skill takes that engine (via voacapl, the modern Linux/GFortran port, on macOS/Linux, or the native NTIA/ITS Windows engine on Windows) and wires it into Claude Code as a "skill" — a capability Claude can reach for on its own.

The skill is free and open-source, with the code available on GitHub. Below, Reid provides some more examples of what you can ask Claude once it has access to VOACAP data.