NAME

       multimon-ng - program to decode radio transmissions

SYNOPSIS

       multimon-ng [options] [input_file]

DESCRIPTION

       This  manual  page documents briefly the multimon-ng command. This manual page was written
       for Debian because the original program does not have a manual page.

       The multimon-ng software can decode a variety of digital transmission modes commonly found
       on  VHF/UHF  radio.  A  standard  PC  soundcard  is  used  to  acquire  the  signal from a
       transceiver. The decoding is done completely in software. Currently, the  following  modes
       are supported:

              •   AX.25

                  •   1200 Baud AFSK

                  •   2400 Baud AFSK (2 variants)

                  •   4800 Baud HAPN

                  •   9600 Baud FSK (G3RUH)

              •   POCSAG

                  •   512 Baud

                  •   1200 Baud

                  •   2400 Baud

              •   Selective call

                  •   CCIR

                  •   EEA

                  •   EIA

              •   Frequency Shift Keying

                  •   1200 Baud FSK (2200/1200 Hz)

                  •   1200 Baud FSK (2300/1100 Hz)

                  •   1200 baud FMS FSK

              •   Miscellaneous

                  •   DTMF

                  •   CW/Morse

                  •   EAS

                  •   FLEX

                  •   SCOPE

                  •   X10

                  •   ZVEI

       An  arbitrary  set  of  the  above  modes  may  run  concurrently on the same input signal
       (provided the CPU power is sufficient), so you do not have to know in advance  which  mode
       is used. Note however that some modes might require modifications to the radio (especially
       the 9600 baud FSK and the POCSAG modes) to work properly.

       AX.25 - Amateur Packet Radio protocol datagram format.
       DTMF - Dual Tone Multi Frequency. Commonly used in in-band telephone dialing.
       EAS - Emergency Alert System.
       FLEX - a paging format.
       POCSAG (Post Office Code Standards Advisory Group) is a common paging transmission format.
       SCOPE - show samples in a rudimentary oscilloscope display on an X server.
       X10 - a home automation protocol.
       ZVEI - The German Electrical and  Electronic  Manufacturers'  Association  -  paging  tone
       format.

OPTIONS

       -t <type>
              Input file type (any other type than raw requires sox).  Allowed types: raw aiff au
              hcom sf voc cdr dat smp wav maud vwe.

       -a <demod>
              Add demodulator (see below).

       -s <demod>
              Subtract demodulator.

       -c     Remove all demodulators (must be added with -a <demod>).

       -q     Quiet output messages.

       -v <num>
              Verbosity level (0-10).  For POCSAG and MORSE_CW '-v1' prints decoding statistics.

       -h     Print the help.

       -A     APRS mode (TNC2 text output).

       -m     Mute SoX warnings.

       -m     Call SoX in repeatable mode (e.g. fixed random seed for dithering).

       -n     Don't flush stdout, increases performance.

       -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: Disables auto-detection and forces decoding of data as <mode>  (<mode>  can
              be 'numeric', 'alpha', 'skyper' and '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 (default: US), where <cs> is one of: US, FR, DE, SE

       -o <time>
              CW: Set threshold for dit detection (default: 500)

       -d <time>
              CW: Dit length in ms (default: 50)

       -g <time>
              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 <label>
              Add a label to the front of every printed line

       Where <demod> is one of: 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
       The -a and -s options may  be  given  multiple  times  to  specify  the  desired  list  of
       demodulators.

EXAMPLE

       Decode  signal  modulations  from  a  sound  file  /tmp/message.wav  without using a SCOPE
       display:
       multimon-ng -s SCOPE -t wav /tmp/message.wav

       With no input file specified, the  program  listens  directly  to  the  sound  card  using
       PulseAudio.  So to decode (only) DTMF tones on the sound card input:
       multimon-ng -a DTMF

NOTICE

       Please  note that monitoring commercial services may be prohibited in some countries, this
       software should therefore only be used to monitor the amateur radio service.

BUGS

       The DTMF and ZVEI decoders have more frequent spurious detection reports.

AUTHOR

       This manual page was written by A. Maitland Bottoms <bottoms@debian.org>, for  the  Debian
       GNU/Linux system (but may be used by others).  This is free software. you can redistribute
       it and/or modify it under the terms of the GNU General Public License as published by  the
       Free Software Foundation; either version 2 of the License, or any later version.

                                           July 7, 2019                            MULTIMON-NG(1)