Logging on MacLoggerDX with Fldigi

Posted by Fred C (W6BSD) on Aug 11 2019

One of my favorite activities on the radio is making contacts using digital modes. I'm not talking about FT8. I mean real conversations using modes such as Olivia, Contestia, Domino, PSK31, etc. To make these contacts I use a software called Fldigi. I think I have made at least one contact on each of the digital modes available through that software. Once I am done with a QSO1 I log my contact in a software called MacLoggerDX.


Until a few days ago, I was using an AppleScript program originally written by Ryan Clarke KJ6MSJ, called Log2MLDX.scpt. This script can be found in the utility directory of the MLDX2 installation image. It works fine but has a few issues.

Sometimes it takes a long time to establish the communication channel between Fldigi and the logging software. This is particularly annoying because Fldigi freezes until the Log2MLDX is done running. During that time the radio sends an empty carrier.

I also wanted to be able to use an IP connection instead of the internal AppleScript inter-process communication mechanism. This would allow me to run Fldigi on a Raspberry Pi, or a Linux machine and log the contacts on my Mac.

The new version of WSJT-X3 logs the contact made with this software exactly the way I want. The author4 of WSJT-X had the good idea of releasing the source code for WSJT-X. I was able to look into the design of the protocol that provides an interface between WSJT-X and the external logger.

With the information learned reading WSJT-X code, I wrote a python program called fllog. The program is run from a Fldigi macro. Fllog crafts a UDP packet containing an ADIF5 line containing the information provided by Fldigi, The packet is then sent through IP to MacLoggerDX.

In the new version of his software, Joe Taylor has standardized how WSJT-X talks to the external world. I haven't tested it but fllog should also work with other logging software.

The fllog program can be found on my github account.


To install fllog follow the next steps

Download from GitHub

$ git clone https://github.com/0x9900/fllog
Cloning into 'fllog'...
remote: Enumerating objects: 26, done.
remote: Counting objects: 100% (26/26), done.
remote: Compressing objects: 100% (16/16), done.
remote: Total 26 (delta 10), reused 21 (delta 9), pack-reused 0
Unpacking objects: 100% (26/26), done.

Install the software

By default, the fllog program will be installed in /usr/local/bin/fllog You can edit the installation script if you want to install fllog in a different place. You can also copy the program fllog into the Fldigi script directory. This directory is usually located in $HOME/.fldigi/scripts/.

$ cd fllog
$ sudo ./install.sh

Installing fllog into /usr/local/bin

To complete the installation, you need to create a logging macro
containing the following line:


As an example, here is the macro I use when I am done with my QSO:

<NAME>, Thank you for the QSO on <BAND> / <MODE>.
I look forward to seeing your signal on my waterfall, 73.
<ZDT> <CALL> de <MYCALL> sk


Once the software is installed you can add the line <EXEC>/usr/local/bin/fllog</EXEC> to one of your macros. (Fix the path, if you installed fllog in a different directory,) Every time you click on that macro the contact will be automatically logged onto MacLoggerDX.

Fllog use UDP and MacLoggerDX needs to be running for the contact to be logged.


If you have problems with fllog, you can add the option -d to the macro. All the environment variables will be logged into the file /tmp/fllog.debug. You can post a message here or send me an email and I will help you debug the program.

Example: <EXEC>/usr/local/bin/fllog -d</EXEC>


With fllog, your logging will work faster and Fldigi will not freeze for 20 or 30 seconds. You will also be able to log your QSOs through the network, from any type of machine.

  1. Amateur radio contact, in amateur radio jargon 

  2. The MacLoggerDX users are calling it MLDX 

  3. Software developed by Joe Taylor know for digital modes such as FT8, FT4, JT65, etc 

  4. Joe Taylor K1JT 

  5. ADIF is an open standard for the exchange of data between ham radio software from different vendors 

 Fldigi      MacLoggerDX