rtl_fm demodulation guide

rtl_fm_demod.sh

# rtl_fm demodulation guide
# based on excerpts from: http://kmkeen.com/rtl-demod-guide/index.html
# requires rtl-sdr (rtl_fm bundled), sox for audio, multimon for pager decoding

# broadcast FM radio
rtl_fm -W -f 89.1M | play -r 32k -t raw -e signed-integer -b 16 -c 1 -V1 -

# police scanner
rtl_fm -N -E -f 154.42M -f 154.75M -f 154.82M -f 154.89M -s 12k -o 4 -g 49.2 -l 70 | play -r 12k ...

# airband scanner
rtl_fm -M -f 118M:137M:25k -s 12k -g 49.2 -l 280 | play -r 12k ...

# pager decoder
rtl_fm -N -E -f 929.77M -s 22.5k -o 4 -g 11.5 -l 250 | multimon -t raw /dev/stdin