Running offline at a field day or open day
DXChrono is designed to keep working when the shack PC or Raspberry Pi has no internet for part of the day. You do not need Cloudlog or live cluster feeds for the clock, grey line, N1MM map pins, or Special Event banner to keep running.
Before you leave home (recommended)
- Check the time — On a Pi without network at boot, set the clock manually or wait for NTP if you have it. The UTC clock and N1MM QSO times depend on correct system time.
- Download the map — At home with internet, open the packaged app once so the world picture downloads, or (from source) run the map download script so you are not left with a blank placeholder on site.
- Satellite TLE cache — Leave Settings → Sats → Cache TLE on disk enabled (default). After one successful download, ISS and other sats still track after restart without internet. File:
~/.dxchrono/satellite_tle_cache.json. - N1MM today cache — Leave Settings → N1MM → Cache today’s QSOs on (default) if you use Special Event mode. Today’s UTC contacts repopulate map pins and the “last worked” banner after a restart. File:
~/.dxchrono/n1mm_today_qsos.json. - Widget layout — Arrange panels in windowed or fullscreen once; positions are saved separately for each mode.
What works without internet
- UTC clock, grey line, sun/moon, and band panels (last good solar / HF / VHF values stay on screen — the footer shows offline when a refresh cannot run).
- N1MM+ UDP — Live QSOs, status panel, and map markers from the logging PC on the LAN (no cloud required).
- Special Event mode — Scrolling last-worked banner, contacts today, and event branding from N1MM and/or cached today QSOs (see Special Event).
- Local ADIF logbook — If you point Settings at a local
.adifile on disk, the logbook panel and map markers work offline. - Satellite tracking — With cached TLEs, footprints and pass predictions continue. When the internet is back, Desktop refreshes the file about every six hours while it is left running; until then it keeps the last download.
What needs internet (or will show stale/offline)
- Cloudlog, QRZ Logbook, DX Cluster, PSK Reporter, Reverse Beacon, SOTA, POTA, contest calendar, aurora/MUF/tropo overlays, SpE heatmap, live HF conditions refresh, and software update checks.
- QRZ XML lookup for new spots — spots still plot from the prefix table; finer positions return when QRZ is reachable again.
For a minimal offline desk: turn off Cloudlog and cluster widgets you will not use, keep N1MM and Special Event on, and lower Settings → Display → FPS on a Pi if CPU is tight (see Troubleshooting).
During the event
- Press R only when you have connectivity — it forces a background refresh of solar data and logbooks (see Controls).
- Press B to pause or resume the Special Event banner scroll while you read a callsign.
- Press N to mute watch-list alert sounds and cards if the band is busy.
- Use G to switch 2D map / 3D globe if you want a simpler 2D view on a small screen.
After you are back online
Press R once to refresh Cloudlog, QRZ, solar data, and cluster feeds. Check Settings → License if validation was skipped offline and you need to confirm your key.