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Fldigi FAQ

Here you can find answers to some of the most frequently asked questions about Fldigi.

You are invited to edit this page and add FAQs on topics that you are familiar with or have answered yourself. However, please do not add unanswered questions and try to keep the answers brief. Long answers should be in separate pages and linked to below.

General information

What is fldigi?

Fldigi (__F__ast __L__ight __Digi__tal Modem Application) is a program for transmitting and receiving signals via a radio transceiver. It includes support for most digital modes used on the amateur radio bands, as well as many related
functions (logging, transceiver control, sound card calibration and frequency analysis).

Is fldigi free software?

Fldigi is Free Public Domain Software and can be modified and redistributed under the terms of the GNU license.

How do I obtain fldigi?

Fldigi can be found at the W1HKJ main web site, and on Source Forge.

Installing Fldigi

What are the minimum hardware requirements for fldigi?

It is recommended that a process of at least a 1.2 GHz for most digital modes, and at least a 1.6 GHz processor for CPU-intensive modes like DominoEX and Thor. A faster CPU may be needed for multiple PSK decoding. A sound card interface to a transceiver or receiver/transmitter which supports single-sideband is required for encoding and decoding digital transmissions.

Fldigi can control frequency, mode and other parameters of many transceiver models via

Which operating systems does fldigi run on?

  • Fldigi should run on all POSIX/X11 systems (OpenBSD, FreeBSD, Linux, Solaris, etc.).
  • It is available as dmg installation file for OS-X / macOS (10.4 or newer)
  • All versions of Windows 2000 and newer

I want to run the Linux version of fldigi. Do I need to build it from source?

Fldigi is available as a pre-compiled binary from various Linux distributions. Note that this might not be the most current version. It is highly recommended that Linux users learn to build fldigi and it's peer applications from source.

Where can I find the alpha (test) releases?

Source and binaries for the latest alpha release can be downloaded from (https://www.w1hkj.org/alpha). Alpha releases may have bugs; we advise you to make a backup copy of your fldigi configuration files. You can also use the fldigi command line parameter ''--config-dir'' to specify a directory in which to test a new installation.

How can I toggle transmit and receive without using a macro?

Press Ctrl-T/Ctrl-R or the Pause key inside the transmit text area.

Why does fldigi access the Internet?

Short answer: it doesn't unless you tell it to. But it muse have access to socket services on address 127.0.0.1, local host. Users of certain "personal firewall" programs for Windows (e.g., Zone Alarm) may see alerts about fldigi's network usage. While fldigi does open several network sockets, they are all bound to the local host address and therefore only accessible by programs running on the same machine.

The sockets are used for:

The latter means that fldigi will generate network traffic on the localhost loopback interface even when no other programs are using fldigi's network servers.

Note that fldigi also has features that involve actual internet access (''e.g.'', the PSK Reporter module), but those are activated by the user.

How can I receive (and decode) SYNOP and SHIP Weather reports ?

SYNOP (Also called FM-12) is a numerical code used for reporting weather observations. These reports, along with FM-13, i.e. SHIP data, are also transmitted are transmitted in RTTY by the Deutscher Wetterdienst (German Meteorological) at regular times.

More information is available in the Fldigi Manual, and on this wiki page.

Related

Wiki: faq_main
Wiki: synop_faq