WSJT-X integration with N3FJP Software

Connecting WSJT-X and N3FJP Software provides the following benefits:

  • Direct logging from WSJT-X into N3FJP Software
  • Callsign color coding for needed stations
  • Duplicate station checking
  • Use rig interface from N3FJP Software


WSJT-X communicates with N3FJP Software using UDP Unicast or Multicast messages.  In order for N3FJP Software to communicate to WSJT-X for features such as highlighting, Accept UDP Requests must be enabled in WSJT-X > Settings > Reporting

To enable listening for WSJT-X messages in N3FJP Software, select Listen for WSJT in the Settings > Application Program Interface > WSJT Interface section.  The Configure button will allow for adjusting IP/Port and customize the colors that appear in WSJT-X.  The initial configuration will attempt to match the current WSJT-X settings.  Msg Rcvd! will flash if currently receiving messages from WSJT-X.


Color highlighting in WSJT-X defaults to the following scheme:

Color Category
- Red - Duplicate call on Band and Mode
- Green - Unconfirmed Country
- Blue - Unconfirmed State
- Purple - Unconfirmed Grid
No color Station has not been worked, but the country, state, and grid are all confirmed

Below are the standard configuration schemes when connecting with WSJT-X:

Configuration Scheme Use Case
Local Unicast WSJT-X communicates with one companion application on the same system
Remote Unicast WSJT-X communicates with one companion application across the network
Multicast WSJT-X communicates with multiple companion applications both on the same system and local area network.

Local Unicast is configured by default, but you may want to change the configuration based on your use case.  For users that wish to connect multiple applications with WSJT-X, see the Multicast section.  Multicast will allow for additional applications such as GridTracker and JTAlert to communicate with WSJT-X alongside N3FJP Software.

Local Unicast


Local Unicast is the simplest configuration, but only allows for one application to communicate with WSJT-X.  If you are only running WSJT-X and AC Log, for instance, this will work fine.  If running additional companion software, however, such as GridTracker and JTAlert, only one application (usually the first started) can receive messages from WSJT-X at a time.

To use Local Unicast, set the IP address to for both WSJT-X (Settings > Reporting > UDP Server) and N3FJP Software and ensure the port numbers match.

If another application is currently listening for WSJT-X, N3FJP Software will display the following message when activating WSJT-X integration and will be unable to receive messages from WSJT-X until the other software is closed.


Remote Unicast


For use cases where only N3FJP Software needs to communicate with WSJT-X, but the programs are running on separate systems, Remote Unicast can be used to send the messages over the network.  This can be useful, for example, if WSJT-X is running on a Linux system and AC Log is running on a separate Windows system, but you still want to take advantage of contact logging and color coding.

To send WSJT-X messages over the network, set the Settings > Reporting > UDP Server in WSJT-X to either the IP address or hostname of the system running N3FJP software and ensure the port number matches.



When using multiple applications in communication with WSJT-X such as Grid Tracker and JTAlert alongside N3FJP software, a Multicast configuration will allow all applications to work in tandem.

A Multicast IP is an address in a special range between and  When using an IP address in this range, multicast will be enabled.  Instead of WSJT-X sending messages to a single application, it will send to all applications configured to listen on the multicast group (or IP).

WSJT-X recommends using a multicast IP of in Settings > Reporting > UDP Server.  The same IP will need to be set in N3FJP Software at Settings > Application Program Interface > WSJT Interface.  If using a newer version of WSJT-X, additional Outgoing interfaces may also need to be selected in order to support network communication.



WSJT-X will now send messages to anyone listening on the same port and multicast group.  Be aware, however, that this also includes other systems on your Local Area Network.  This can be useful if WSJT-X and N3FJP Software are running on separate systems, but if you have another station on your network please choose a different IP or Port so that messages from other stations are not mixed with yours.

Rig Interface

A note on Rig Interface -- only one program can connect directly to your rig, so you can either let Amateur Contact Log or WSJT-X perform rig interface.

  • If you want WSJT-X to perform rig control, from AC Log's menu options click Settings > Rig Interface and select None from the rig list (be sure to click the Save Settings button below the rig list first to save your working settings).  Then configure rig interface in WSJT accordingly. 
  • Alternatively, you can set AC Log to perform rig interface and set WSJT-X's rig selection to None.  Please note that if you go this route, it is best to set AC Log to return Mode by Frequency and enable Return All Mapped Digital Modes.  Otherwise,  AC Log will display SSB for mode until you log a contact, but the mode will be saved as the proper digital mode either way.  AC Log will set most rigs to transmit as WSJT-X transmits, so WSJT remains fully functional with AC Log performing rig control.