NAME

       multimon - program to decode radio transmissions

SYNOPSIS

       multimon [options] [input_file]

DESCRIPTION

       This  manual  page  documents  briefly the multimon command.  This manual page was written for the Debian
       GNU/Linux distribution because the original program does not have a manual page.

       The multimon software can decode a variety of digital transmission modes commonly found on 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
                        o 1200 Baud AFSK
                        o 2400 Baud AFSK (2 variants)
                        o 4800 Baud HAPN
                        o 9600 Baud FSK (G3RUH)

           * POCSAG
                        o 512 Baud
                        o 1200 Baud
                        o 2400 Baud

           * Miscellaneous
                        o DTMF
                        o ZVEI
                        o SCOPE

       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
       POCSAG (Post Office Code Standards Advisory Group) is a common paging transmission format.
       DTMF - Dual Tone Multi Frequency. Commonly used in in-band telephone dialing.
       ZVEI- The German Electrical and Electronic Manufacturers' Association - paging tone format.
       SCOPE - show samples in a rudimentary oscilloscope display on an X server.

       Multimon does not decode Morse code signals.

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

       -s <demod>
              subtract demodulator

       -v <num>
              verbosity level (0-10)

       -q     quiet output messages

       Where  <demod>  is  one  of:  POCSAG512  POCSAG1200  POCSAG2400 EAS AFSK1200 AFSK2400 AFSK2400_2 HAPN4800
       FSK9600 DTMF ZVEI 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 -s SCOPE -t wav /tmp/message.wav

       With no input file specified, the  program  listens  directly  to  the  sound  card  using  the  /dev/dsp
       interface.  So to decode (only) DTMF tones on the sound card input:
       multimon -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.

SEE ALSO

       gen(1) http://www.qsl.net/kb9mwr/projects/pager/Two-Tone%20Pager%20Decoding%20Using%20Multimon.pdf

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).

                                                  June 19, 2000                                      MULTIMON(1)