SKYWAVE

A TV Guide for the radio bands.

See what's on the air right now across longwave, mediumwave and shortwave — plus the amateur-radio HF nets in session and who's checked into them. One HTML file. Works with no signal.

cdburgess75.github.io/SkyWave — no signup, no download, nothing to configure
📱 On a phone? Save it to your home screen ↓

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Why SkyWave

Radio listening has a discovery problem. Thousands of broadcasts move through the bands every day on schedules buried in a 9,000-row CSV, and the amateur nets that come and go live on a separate logging site. The usual answer is desktop software, printed guides, or both.

SkyWave turns all of it into a single "what's on right now" view that runs on the device already in your pocket — including in the field, with no signal.

• 9,361 broadcast entries spanning 16.3 kHz – 26.2 MHz: longwave, mediumwave and shortwave, not just the SW bands most guides stop at
• Live HF ham nets with full check-in rosters, refreshed automatically
• Grayline, band advice and propagation, computed on-device from your coordinates

No account. No tracking. No server. No build step. The file you open is the app.

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✦ Features

📻 Know what you're hearing

• On Air now — every broadcast transmitting this minute, day-of-week aware, sorted by frequency. Filter by favorites, language, band or free text.
• Identify a signal — heard something on the dial? Type 9420 and get every scheduled station within a ± tolerance you choose, on-air entries first.

📡 Work the nets

• Live nets in session — refreshed automatically, with a tap-to-expand check-in roster: callsign, name, city/state, grid square, net control marked NC.
• Built-in net directory — major national and Southeast-US HF nets (traffic nets, SouthCARS, Maritime Mobile, Hurricane Watch and more), available offline, on-air aware, star-able.

🌗 Catch the opening

• Grayline alerts — a header banner warns you 30 min and 5 min before the grayline window opens, then counts it down live. One tap exports calendar reminders (.ics) so your phone alerts you even with SkyWave closed.
• Band planner — sunrise, sunset, solar noon, day length and plain-language band-by-band advice, computed on your device. No network needed.
• Propagation — live NOAA planetary K-index with an 8-period trend, plus quick links to solar data, VOACAP/Proppy, WebSDR receivers and DX clusters.

🎒 Built for the field

• Genuinely offline — the full schedule is stored on-device; grayline and band advice never touch the network.
• Field extras — band-card export, a printable reference sheet, and a kiosk / shack-monitor mode that keeps the screen awake.
• Yours to keep — star stations and nets, mark catches as "heard today," add your own frequencies alongside everything else.
• Light & dark, any text size — a retro LED clock-radio dark theme (midnight-blue panel, amber VFD readouts with ghost segments under the clocks), a clean light theme, and a built-in text-size control.

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📸 Screenshots

Live nets + check-in roster	On Air (LW / MW / SW)	Identify by frequency

Grayline & band planner	Light theme

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📱 Save it to your phone

SkyWave is a Progressive Web App: saved to your home screen it launches full-screen from its own icon, with no browser chrome — and keeps working with no signal.

Do this once, while online: open the app and tap Ref → ⟳ Update now. That stores the full schedule on your device. From then on, airplane mode is fine.

 iPhone & iPad

1. Open cdburgess75.github.io/SkyWave in Safari — it must be Safari; Chrome and in-app browsers on iOS can't install web apps
2. Tap the Share button (the square with the arrow, bottom of the screen)
3. Scroll down and tap Add to Home Screen
4. Tap Add — SkyWave appears on your home screen like any app

 Android

1. Open cdburgess75.github.io/SkyWave in Chrome
2. Tap the ⋮ menu (top-right)
3. Tap Install app — older versions say Add to Home screen
4. Confirm with Install

Chrome often offers an Install banner on its own after a few seconds — that works too.

🖥️ Desktop

In Chrome or Edge, click the install icon in the address bar (a screen with a down-arrow), or ⋮ → Cast, save and share → Install page as app.

What you get once installed

🚀	Launches full-screen from its own icon — no address bar, no tabs
✈️	Works in airplane mode once the schedule is stored
🔄	Updates itself in the background and shows a banner when a new version is ready
💾	Favorites, location and settings persist on-device

On first launch, a 60-second wizard asks for your location (GPS or manual) to power the grayline and grid-square features — you can skip it and set it later from the Ref tab. New here? The full User Guide walks through every tab in plain English.

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🚀 Quick start (run it locally)

The app is one static file — all you need is something that serves it.

Prerequisites

Requirement	Why	Notes
Any static file server	Service workers won't run from file://	Python, Node, anything
Node.js 20+	Only for the test suite	Not needed to run the app

There is no install step and no build step — nothing to npm install to run the app.

Clone

git clone https://github.com/cdburgess75/SkyWave.git
cd SkyWave

Run

python3 -m http.server 8000
# → open http://localhost:8000

Prefer Node?

npx serve .            # or: npx http-server -p 8000

Opening index.html straight from disk works for everything except the service worker (so: no offline caching, no install prompt).

Test

npm install -D jsdom   # one-time — the only dev dependency
npm test               # all three suites

node test/smoke.mjs        # script syntax, id coverage, full jsdom boot
node test/domain.mjs       # on-air windows, day/season rules, sun times, grayline alerts, .ics export
node test/nets-parser.mjs  # live-net feed shapes

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🔧 How it works

SkyWave is a single index.html — HTML, CSS and vanilla JavaScript ("use strict"), with a service worker for offline support. There is no framework and no build step; the file you open is the app.

SkyWave/
├── index.html              ← the entire application (HTML + CSS + JS)
├── sw.js                   ← service worker: cache-first shell, self-update
├── manifest.webmanifest    ← PWA install manifest
├── icons/                  ← SVG + PNG app icons
├── scripts/
│   ├── fetch-eibi.mjs      ← builds the broadcast-schedule mirror
│   └── fetch-nets.mjs      ← builds the live-nets + roster mirror
├── .github/workflows/      ← CI (tests), both data mirrors, Pages deploy
├── test/                   ← Node test suites (smoke, domain, nets-parser)
└── docs/                   ← user guide, architecture notes, data sources, images

Data flow. One array is the single source of truth: built-in time stations and net directory + your own frequencies + the parsed EiBi schedule. Every view is a filter over that array, rendered through event delegation. The schedule lives in IndexedDB; small state stays in guarded localStorage.

Staying dependency-free. The app never calls a third party — not for the schedule, not for the nets, not through anyone's CORS proxy. Both live feeds are fetched server-side by scheduled GitHub Actions in this repo and mirrored to a data branch the app reads over CORS-open raw.githubusercontent.com: the EiBi schedule daily, live ham nets (with check-in rosters) on a rolling schedule. Everything else — grayline and band advice — is computed on-device.

Design rules held throughout: no runtime dependencies, every storage access wrapped in try/catch, all rendered data escaped, and every network feature caches its last result and renders an explicit offline state.

📖 Deeper detail: docs/ARCHITECTURE.md · docs/DATA_SOURCES.md · HANDOFF.md

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🛠️ Tech stack

Layer	Choice	Why
UI	Vanilla JS + HTML + CSS	No framework, no bundler — one readable, portable file
Offline	Service worker + manifest	Cache-first shell; schedule in IndexedDB
Live data	GitHub Actions as a server-side mirror	Zero third-party calls from the app
Hosting	GitHub Pages	Static, free, nothing to maintain
Tests	Node + jsdom	Three suites, one dev dependency

(No React, no Tailwind, no Node at runtime — the absence of a stack is the point: the app stays a single auditable file that works offline forever.)

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📚 Data sources & credits

Source	Used for	Terms
EiBi © Eike Bierwirth	LW / MW / SW broadcast schedule	Free to copy & distribute with attribution — mirrored server-side by this repo
NetLogger	Live ham nets + check-in rosters	Mirrored server-side by this repo's Action
NOAA SWPC	Planetary K-index	Public API
HamQSL N0NBH/K4HG	Solar conditions	Linked & credited

No third-party CORS proxy sits between you and any source. The roster mirror deliberately drops the street address, ZIP, county and member ID the upstream API also returns — only ham-public fields (callsign, first name, city/state, grid) are published.

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🤝 Contributing

Small, focused PRs are welcome. Ground rules (full detail in HANDOFF.md):

• Keep it one file. No frameworks, no build step, no runtime dependencies.
• Offline-first is the contract. A network feature must cache its last result and render a sensible offline state.
• Escape everything rendered from data.
• Run the tests before pushing — npm test.
• Version bumps are CalVer (YYYY.MM.DD.NNN) in index.html and the sw.js cache name, with a CHANGELOG.md entry.

SkyWave is a listening guide, not a logger — operating-side features (QSO logging, POTA/SOTA spotting, ADIF) are out of scope.

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📄 License

Code is MIT. Schedule data remains © EiBi under its own terms — please don't relicense the data.

▶ Open SkyWave now

_{Built for offline field use · all times UTC · 73}