fldigi - digital modem program for hamradio operators

       Fldigi was written by

       •   David Freese, W1HKJ.

       •   Stelios Bounanos, M0GLD.

       •   Leigh L. Klotz, Jr., WA5ZNU.

       Fldigi also includes code written by others. Among them are

       •   Tomi Manninen, OH2BNS.

       •   Pawel Jalocha, SP9VRC.

       •   Hamish Moffatt, VK3SB.

       This manual page was written by Stelios Bounanos <sb[at]enotty(dot)net>.

       Yes.

       License GPLv3+: GNU GPL version 3 or later.

                                                   02/10/2025                                          FLDIGI(1)

Fldigi is a cross-platform multi-modem program for most of the digital modes used by radio amateurs
       today: CW, PSK, MFSK, MT-63, RTTY, Hellschreiber, DominoEX, Olivia, THOR and Throb are all supported. It
       can also help calibrate a sound card to a time signal and do on-air frequency measurement tests. Fldigi
       features basic rig control, logging, and contest operation, “panoramic” PSK decoding, a PSK Reporter
       client, and remote control via XML-RPC.

       Fldigi uses several environment variables, mainly set for child processes created by the <EXEC> macro and
       the notifier.

   Generalvariables
       FLDIGI_BROWSER
           The web browser to use for http and file URIs. Overrides $BROWSER and xdg-open(1).

   Macrovariables
       The following variables are created in the environment of the child process that is forked by the <EXEC>
       macro. They are empty if values are not available.

       FLDIGI_RX_IPC_KEY
           The receive message queue key.

       FLDIGI_TX_IPC_KEY
           The transmit message queue key.

       FLDIGI_XMLRPC_ADDRESS
           The XML-RPC server address string.

       FLDIGI_XMLRPC_PORT
           The XML-RPC server port string.

       FLDIGI_ARQ_ADDRESS
           The ARQ server address string.

       FLDIGI_ARQ_PORT
           The ARQ server port string.

       FLDIGI_VERSION
           The version string.

       FLDIGI_PID
           The process ID of the parent fldigi process.

       FLDIGI_CONFIG_DIR
           The configuration directory.

       FLDIGI_MY_CALL
           The operator’s callsign.

       FLDIGI_MY_NAME
           The operator’s name.

       FLDIGI_MY_LOCATOR
           The operator’s IARU (Maidenhead) locator.

       FLDIGI_MODEM
           The short modem name.

       FLDIGI_MODEM_LONG_NAME
           The long modem name.

       FLDIGI_DIAL_FREQUENCY
           The rig (radio) frequency.

       FLDIGI_AUDIO_FREQUENCY
           The modem (audio) centre frequency.

       FLDIGI_FREQUENCY
           The actual receive/transmit frequency, i.e. the sum of rig and modem frequencies taking into account
           the rig sideband.

       FLDIGI_LOG_FREQUENCY
           The text (frequency in MHz) contained in the QSOFreq log field.

       FLDIGI_LOG_TIME_ON
           The text (QSO start time) contained in the (time) On log field.

       FLDIGI_LOG_TIME_OFF
           The text (QSO end time) contained in the (time) Off log field.

       FLDIGI_LOG_CALL
           The text (other station’s callsign) contained in the Call log field.

       FLDIGI_LOG_NAME
           The text (other station’s name) contained in the Name log field.

       FLDIGI_LOG_RST_IN
           The text (received RST) contained in the (RST) In log field.

       FLDIGI_LOG_RST_OUT
           The text (sent RST) contained in the (RST) Out log field.

       FLDIGI_LOG_QTH
           The text (other station’s QTH) contained in the QTH log field.

       FLDIGI_LOG_LOCATOR
           The text (other station’s Maidenhead locator) contained in the Loc log field.

       FLDIGI_LOG_NOTES
           The text (free-form notes) contained in the Notes log field.

       FLDIGI_AZ
           The text (azimuth in degrees to other station) contained in the Az log field.

   Notifiervariables
       The following variables are created in the environment of child processes created by the notifier.

       FLDIGI_NOTIFY_STRi
           These variables (i in [0,9]) contain substrings matched by capturing groups in the event’s regular
           expression. 0 contains the whole matched text.

       FLDIGI_NOTIFY_STR_NUM
           The number of substrings available.

       FLDIGI_NOTIFY_CALLSIGN
           Builtin event types that match callsigns will place the callsign in this variable.

       FLDIGI_NOTIFY_TEXT
           The complete string that matched the event’s regular expression.

       FLDIGI_NOTIFY_AUDIO_FREQUENCY
           The modem frequency.

       FLDIGI_NOTIFY_EVENT
           The event type.

       FLDIGI_NOTIFY_COUNTRY
           The station’s country name (for events of type "station heard twice").

   Debuggingvariables
       The following variables are only used if fldigi was built with debugging support (--enable-debug), or
       they are only useful when debugging specific modules.

       FLDIGI_NO_EXEC
           If set, this variable disables glibc’s malloc debugging, which fldigi enables by default when built
           for debugging.

       FLDIGI_TRACE_LOCKS
           Traces Fl::lock() calls.

       FLDIGI_HAMLIB_DEBUG
           Initialises hamlib in debug mode.

       fldigi --wfall-height 144 --font sans:11 -fg "#c0c0c0" -bg "#5f5f63" -bg2 "#19213b"
           This is how the author of this document invokes fldigi.

       fldigi --xmlrpc-deny "main.(tx|tune|run_macro)"
           Unregister XML-RPC methods that may transmit.

       ssh -L 7362:localhost:7362 remote-host xvfb-run fldigi -display :99
           Start fldigi on remote-host under a “fake” X server. (The xvfb-run(1) utility is available on Debian
           systems). The remote “headless” fldigi is then controlled via XML-RPC on port 7362, i.e from flrig,
           flamp etc.

       fldigi --benchmark-input 480000 --benchmark-modem 1
           Benchmark the DominoEX-4 modem with 480K audio samples.

       fldigi --benchmark-input audio.wav --benchmark-modem 25 --benchmark-frequency 1500 --benchmark-afc 1
       --benchmark-squelch 1 --benchmark-squelch-level 5.0 --benchmark-output out.txt
           Read audio.wav (whose sample rate must be 8000Hz in this case) and decode BPSK-31 signals at 1500Hz.
           AFC is enabled and the squelch is set to 5%. Decoded text is saved to out.txt.

       Various files and subdirectories are created in $HOME/.fldigi. Some of the most interesting ones are
       listed below.

       fldigi_def.xml
           The main settings file.

       fldigi.prefs
           The “status” file. Stores window geometries, button states, current modem, current audio frequency,
           squelch level, and so on.

       status_log.txt
           The event log.

       macros/macros.mdf
           The default macro file.

       palettes/
           This directory contains waterfall palettes.

       scripts/
           This directory is added to the PATH environment variable of the child process that runs <EXEC>
           macros.

       logs/
           This directory contains logged received and sent text (when such logging is enabled), including the
           default logbook database, logbook.adif.

       images/
           Received MFSK images are automatically saved in this directory.

       freqanalysis.csv
           This file is written by the frequency analysis modem. The fields are dial frequency, audio frequency,
           and offset. See documentation for details.

           Note

           The following files are used if present. They must be downloaded and copied to ~/.fldigi/ by the
           user.

       cty.dat
           List of DXCC entities and callsign prefixes; used to display tooltips in the received text buffer,
           and also to auto-fill the Country, Locator and Azimuth log fields. Available at
           http://www.country-files.com/cty/.

       lotw1.txt
           List of known LOTW users (one callsign per line); used for the received text tooltips. Available at
           http://www.hb9bza.net/lotw/.

       AGMemberList.txt or eqsl.txt
           List of “Authenticity Guaranteed” eQSL users (one callsign per line); used for the received text
           tooltips. Available at http://www.eqsl.cc/QSLcard/Programming.cfm.

       fldigi - digital modem program for hamradio operators

       Long options begin with two hyphens and are handled by fldigi. The option names may be abbreviated to any
       unambiguous substring, and the option argument may be separated from the name by a space or equals sign,
       as per getopt(3).

       Short options begin with a single hyphen and are passed directly to FLTK. They may be abbreviated only as
       indicated.

       --config-dirDIRECTORY
           Look for and store configuration files in directory DIRECTORY, which is created if it does not exist.
           Defaults to “$HOME/.fldigi”.

       --rx-ipc-keyKEY
           Set the receive message queue key. May be given in hex if prefixed with “0x”. Defaults to “9876” or
           “0x2694”.

       --tx-ipc-keyKEY
           Set the transmit message queue key. May be given in hex if prefixed with “0x”. Defaults to “6789” or
           “0x1a85”.

       --arq-server-addressHOSTNAME
           Set the ARQ TCP server address. Defaults to “127.0.0.1”.  HOSTNAME may be any nodename string
           accepted by getaddrinfo(3).

       --arq-server-portPORT
           Set the ARQ TCP server port. Defaults to “7322”.  PORT may be any servicename string accepted by
           getaddrinfo(3).

           Note

           The --xmlrpc-* options are only available if fldigi was built with XML-RPC support.

       --xmlrpc-server-addressHOSTNAME
           Set the XML-RPC server address. Defaults to “127.0.0.1”.

       --xmlrpc-server-portPORT
           Set the XML-RPC server port. Defaults to “7362”.

       --xmlrpc-allowREGEX
           Allow only the methods whose names match REGEX.  REGEX is a POSIX extended regular expression.

       --xmlrpc-denyREGEX
           Allow only the methods whose names do not match REGEX.

       --xmlrpc-list
           List all available XML-RPC methods and exit. May be preceded by the --xmlrpc-allow or --xmlrpc-deny
           options to verify their effect.

       --cpu-speed-test
           Perform the CPU speed test that is normally done when fldigi is run without an existing configuration
           directory. Results are shown in the event log and options may be changed to the recommended values
           for the measured CPU speed.

       --noise
           Unhide controls for adding noise to the transmitted signal.

       --wfall-only
           Hide all main window widgets except the menu bar and waterfall (with its associated controls). Meant
           to be used with external programs that control fldigi with XML-RPC.

       --debug-levelLEVEL
           Set the event log verbosity.  LEVEL is clamped to the range [0,5]; for Quiet, Error, Warning, Info,
           Verbose and Debug. Defaults to “3” (Info).

       --version
           Print version information and exit.

       --build-info
           Print build information and exit.

       --help
           Print options summary and exit.

   StandardFLTKoptions-bg,-backgroundCOLOUR
           Set the background colour.

       -bg2,-background2COLOUR
           Set the secondary (text) background colour.

       -di,-displayDISPLAY
           Specifies the X server to connect to; see X(7).

       -dn,-dnd or -nodn,-nodnd
           Enable or disable drag and drop copy and paste in text fields.

       -fg,-foregroundCOLOUR
           Set the foreground colour.

       -g,-geometryGEOMETRY
           Set the initial window size and position.  Fldigimaynothonourthisoption.

       -i,-iconic
           Start fldigi in iconified state.  Fldigimaynothonourthisoption.

       -k,-kbd or -nok,-nokbd
           Enable or disable visible keyboard focus in non-text widgets.

       -na,-nameCLASSNAME
           Set the window class. Defaults to “Fldigi”.

       -ti,-titleWINDOWTITLE
           Set the window title. Defaults to “fldigi - <callsign>”.

   AdditionalUIoptions--fontFONT[:SIZE]
           Set the widget font and (optionally) size. Defaults to “sans:12”.

   OptionsusefultodevelopersNote

           The --benchmark-* options are only enabled if fldigi was built (exclusively) for benchmarking and
           batch decoding.

       --benchmark-modemID
           Specify the modem. Defaults to “25” (“BPSK31”).

       --benchmark-frequencyFREQ
           Set the modem frequency in Hz. Defaults to “1000”.

       --benchmark-afcBOOLEAN
           Enable or disable modem AFC. Defaults to “false”.

       --benchmark-squelchBOOLEAN
           Enable or disable modem squelch. Defaults to “false”.

       --benchmark-squelch-levelLEVEL
           Set the modem squelch level (1—100%). Defaults to “0.0”.

       --benchmark-inputINPUT
           Specify the input. Must be a positive integer indicating the number of samples of silence to generate
           as the input, or, if fldigi was linked with libsndfile, the name of the input audio file. The
           filename must contain non-digit characters.

       --benchmark-outputFILE
           Specify the output data file. Non-textual output (i.e. Hellschreiber or MFSK images) cannot be saved.
           Default: decoder output is discarded.

       --benchmark-src-ratioRATIO
           Specify the sample rate conversion ratio. Defaults to “1.0” (input is not resampled).

       --benchmark-src-typeTYPE
           Set the sample rate conversion type. TYPE is an integer in the range [0,4]. Defaults to “2” (“Fastest
           SINC Interpolator”).

           WarningThefollowingoptionsshouldnotbereliedupon.Theyarelistedhereonlyforthesakeofcompleteness,andmaybereplacedbyGUIsettingsorremovedaltogetherinafutureversion.--wfall-widthWIDTH
           Set the waterfall width.

       --wfall-heightHEIGHT
           Set the waterfall height.

       --window-widthWIDTH
           Set the minimum window width.

       --window-heightHEIGHT
           Set the minimum window height.

       --exit-afterSECONDS
           Run for approximately SECONDS seconds.

       --frames-per-bufferFRAMES
           Set frames per buffer option to FRAMES when creating PortAudio streams. Defaults to “0” (let
           PortAudio choose).

       Main web site: http://www.w1hkj.com/Fldigi.html

       Sourceforge project page: http://sourceforge.net/projects/fldigi/

       Wiki and bug tracker: https://fedorahosted.org/fldigi/

       More information on MFSK16, DominoEX and other digital modes can be found at http://www.qsl.net/zl1bpu/
       and http://www.w1hkj.com/FldigiHelp/Modes/index.htm

       The PSK Automatic Propagation Reporter site can be found at http://www.pskreporter.info/

       Fldigi is licensed under the GNU GPL, which grants you the right to run the program for any purpose
       (freedom 0). However, permission to use it for the transmission of radio signals can only be obtained
       from the communications authority of your country. When given, this permission almost always comes in the
       form of an amateur radio license.

       If you do not have an amateur radio license you can still have fun using fldigi as a shortwave listener.
       One way to do so is by using the builtin PSK Reporter client to submit realtime spots of transmitting
       stations; see RESOURCES below. All you need is a computer, homebrew SDR receiver, and simple wire
       antenna!

fldigi-shell(1), gmfsk(1), gpsk31(1), grig(1), rigctl(1), xlog(1), getaddrinfo(3), getopt(3), regex(7),
       X(7)

fldigi [OPTIONS]