APRS Tracking
Decode APRS (Automatic Packet Reporting System) amateur radio position reports on VHF.
Amateur Radio
APRS operates on 144.390 MHz (N. America) or 144.800 MHz (Europe). Decodes position, weather, and messages from ham radio operators.
Controls in function bar above map
Antenna Guide
2m band (144–148 MHz) — stock SDR antenna will NOT work
Simple Dipole (Easiest)
- Element length: ~51.5 cm each (quarter-wave at 144.39 MHz)
- Material: Wire, coat hanger, or copper rod
- Orientation: Vertical (APRS is FM, vertically polarized)
- Connection: Center conductor to one element, shield to the other
Commercial Options
- Mag-mount 2m whip: ~$15–25, good mobile/portable option
- 2m/70cm dual-band: ~$20–40, also covers 70cm ham band
- Discone: ~$30–50, wideband but lower gain on 2m
Quick Reference
| APRS freq (N. America) |
144.390 MHz |
| APRS freq (Europe) |
144.800 MHz |
| Quarter-wave length |
51.5 cm |
| Modulation |
FM 1200 baud |
| Polarization |
Vertical |