QBFreak's Blog
Negative PPM value for RTL_FM
On July 1, 2017
A friend was setting up an APRS i-gate with a Raspberry Pi and an RTL-SDR receiver and ran into the issue that he needed to configure it for a negative PPM value for frequency correction. When providing rtl_fm with the PPM correction, it expects it in the format of rtl_fm -p nn where nn is the PPM value. The