FLIR UltraFORCE transmitter EN302 054 400.16 -405.99 MHz meteorological band in 20 kHz steps, creating about 300 separate channels. Frequency stability: < +/- 10 kHz RF power output: <200 mW Channel spacing: 200 kHz modulation: FSK baud rate: 4800? AIRHUB receiver cf SEMTECH sx1278 spec p48 Reverse engineer: Reference: Vaisala RD94 Vaisala NRD41 , pdf NCAR NOAA RTHK bau SPARV Radiosonde , github rs1729 radiosonde github , including dropsonde Fingers-welt forum in German SX1278 FSK & 2 FSK VR2XKP APRS FI in HK APRS direct