multimon-ng Usage Example

Take raw input from rtl_fm (-t raw), add the POCSAG512, POCSAG1200, POCSAG2400, and SCOPE modules (-a POCSAG512 -a POCSAG1200 -a POCSAG2400 -a SCOPE), decode in alpha mode (-f alpha), reading from stdin (/dev/stdin):

root@kali:~# rtl_fm -f 149.614M -s 22050 -p -19 | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -a SCOPE -f alpha /dev/stdin
multimon-ng  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
             (C) 2012/2013 by Elias Oenal
available demodulators: POCSAG512 POCSAG1200 POCSAG2400 EAS UFSK1200 CLIPFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR SCOPE
Enabled demodulators: POCSAG512 POCSAG1200 POCSAG2400 SCOPE
Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Oversampling input by: 46x.
Oversampling output by: 1x.
Buffer size: 8.08ms
Tuned to 149867575 Hz.
Sampling at 1014300 Hz.
Output at 22050 Hz.
Exact sample rate is: 1014300.020041 Hz
Tuner gain set to automatic.

Packages and Binaries:

multimon-ng

The successor to multimon, with support for more modes and improved compatibility with moderns systems. It decodes the following digital transmission modes commonly found on VHF/UHF bands:

POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE CW X10

Multiple decoders can run concurrently on the same signal, which is provided via a file or a pipe. Common setups are: a radio connected via a sound card (may require modifications to the radio); samples provided via a GNU Radio sink or the UDP audio stream in gqrx (via netcat and sox).

Installed size: 130 KB
How to install: sudo apt install multimon-ng

  • libc6
  • libpulse0
  • libx11-6
multimon-ng

Program to decode radio transmissions

root@kali:~# multimon-ng --help
multimon-ng: unrecognized option '--help'
multimon-ng 1.1.9
  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
  (C) 2012-2020 by Elias Oenal
Available demodulators: POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV X10 SCOPE

Usage: multimon-ng [file] [file] [file] ...
  If no [file] is given, input will be read from your default sound
  hardware. A filename of "-" denotes standard input.
  -t <type>  : Input file type (any other type than raw requires sox)
  -a <demod> : Add demodulator
  -s <demod> : Subtract demodulator
  -c         : Remove all demodulators (must be added with -a <demod>)
  -q         : Quiet
  -v <level> : Level of verbosity (e.g. '-v 3')
               For POCSAG and MORSE_CW '-v1' prints decoding statistics.
  -h         : This help
  -A         : APRS mode (TNC2 text output)
  -m         : Mute SoX warnings
  -r         : Call SoX in repeatable mode (e.g. fixed random seed for dithering)
  -n         : Don't flush stdout, increases performance.
  -j         : FMS: Just output hex data and CRC, no parsing.
  -e         : POCSAG: Hide empty messages.
  -u         : POCSAG: Heuristically prune unlikely decodes.
  -i         : POCSAG: Inverts the input samples. Try this if decoding fails.
  -p         : POCSAG: Show partially received messages.
  -f <mode>  : POCSAG: Overrides standards and forces decoding of data as <mode>
                       (<mode> can be 'numeric', 'alpha', 'skyper' or 'auto')
  -b <level> : POCSAG: BCH bit error correction level. Set 0 to disable, default is 2.
                       Lower levels increase performance and lower false positives.
  -C <cs>    : POCSAG: Set Charset.
  -o         : CW: Set threshold for dit detection (default: 500)
  -d         : CW: Dit length in ms (default: 50)
  -g         : CW: Gap length in ms (default: 50)
  -x         : CW: Disable auto threshold detection
  -y         : CW: Disable auto timing detection
  --timestamp: Add a time stamp in front of every printed line
  --label    : Add a label to the front of every printed line
   Raw input requires one channel, 16 bit, signed integer (platform-native)
   samples at the demodulator's input sampling rate, which is
   usually 22050 Hz. Raw input is assumed and required if piped input is used.

Updated on: 2021-Nov-26