Carsten Groen's (OZ9AAR) personal place

WSJT Log Viewer

As I'm active on both 70cm EME and on 23cm EME, I needed a simple tool to help me analyze the signal strengths I receive other stations with. Doing SSB and CW contacts does not (easily) enable this kind of analysis, but for digital contacts this is much easier. The excellent WSJT application (by Joe K1JT and others) are used for almost all digital contacts on EME. 

WSJT logs all traffic it decodes in a single file (ALL.TXT), each line in that file contains either a TX or a RX message. The application presented here, "WSJT Log Viewer" will take the log file from WSJT and analyze and present data from it, both as tabular data and as graphs (features might be expanded in the future).

The application will also show live changes to the selected file, if WSJT decodes frames while the Log Viewer is running, the windows will reflect whatever WSJT decodes! Log Viewer monitors the selected ALL.TXT file for changes every two seconds and updates according to this.

Special thanks to Robert DC1RDB, Ingebrigt LB6B and Dave KG0D for suggestions and for testing the application, and to the many people on moon-net that sent me their ALL.TXT file for testing :) 

When starting the application for the first time, it will look like below:

Click on "File" and open the ALL.TXT file (if a file have been opened previously, you can also reload the same file).

You should then see the window populate with information. Each line represents one day:

The application now shows the basic information it found in the ALL.TXT file:

• My Callsign this is the callsign the application thinks has created the ALL.TXT file.
• Total QSO's (all bands) this will reflect the number of completed QSOs, if a specific band is selected later on in the QSO Details" tab, this will be taken into account.
• Unique Calls (all bands) this is the number of unique callsigns decoded in the file (selected band is taken into account).
• Days with activity (all bands) this is the number of days there have been received signals (selected band is taken into account).
• Signals heard (all bands) this is the number of decoded (received) messages (selected band is taken into account).
• Date Range this shows the first and last data signals was decoded in the ALL.TXT file.

If you select one of the lines, the window at the bottom show small boxes with information for each of the QSOs at that specific day. The information shown in the boxes:

• His best This is the highest SNR value the station was received with during the QSO
• My RPT This is the report the station sent me during the QSO 

(Using the "Band" and "All sessions" dropdown boxes, you can select specific band and if you only want to see entries with actual completed QSOs or not, you can also filter by a specific callsign)

Single clicking on one of the boxes will copy the callsign to the "QSO Detail" tab and show all QSOs with that station (see further down).

Double clicking on one of the boxes will show a window with the raw data from the loaded ALL.TXT file:

Selecting the "Activity Chart" will show all activity from start to end date in the ALL.TXT file as two graphs. The upper one shows the amount of signals for each day, the bottom graph shows the number of decoded (received) signals. Each of the bars in the upper graph are colored with respect to the band operated that specific day, blue is 70cm and green is 23cm. You can see that the 6th day on 23cm, I was also doing 70cm contacts the same day, the bar is both blue and green:

Selecting the "Top Partners" tab will show data for the top 25 stations you have had most QSO's with.

Double clicking on one of the lines will jump to the "QSO Details" tab and show the information for the selected callsign. 

You can also see the total number of QSOs with the station selected (you can filter on band), the number of days with QSOs with the station, the average SNR you have received the station with and the average report you have received from that station.

The two graphs at the bottom shows the best SNR you received the station with, the upper graph is for the QSOs you had with the station, the lower graph shows the SNR you have received the station with, regardless if it was in a QSO with you or not.

You can hover the mouse over one of the dots in the two graphs, a tooltip will then show information for that event:

If you double click on one of the dots, the raw data for the event will be shown:

Using the menuitem "List of initials for selected band" under "Functions", you can get a (text) list of all initials worked, either for all bands or the selected band. The function can be selected if you are on the "Session log" or the "QSO details" tab. It will follow the band selected on the tab in use. You can copy the text to the clipboard and paste it into a document for further usage.

Download

The program is free, but if you like the program and want to support further developments from me, you are more than welcome to make a donation via Paypal to me :) Email address is on my Contact/CV page.

WSJT Log Viewer runs under Windows operating system. There are no installation to be done. The program consists of a single .exe file, simply download this, copy it to a folder and execute it from there.

WSJT Log Viewer will create a configuration file (with the name "LogViewer.cfg") in the folder it is located in, this file contains all settings from the program. If you supply the application with a filename when you start it, it will use this file as configuration file. This enables you to start the program with different setups, depending on what you want to achieve.

Please note, you might get "false positive" virus alerts from Microsoft Defender. This is quite normal, and nothing to worry about.

If you notice "funny things" with saving settings, storing data, please make sure that the program has write access to the folder where you try and write to (for settings problems, the folder where the application is located). Alternatively you might try and start the application in "Administrator mode". 

2026-07-10 OZ9AAR WSJT Log Viewer - Version 1.0.0.7

Previous versions:

2026-07-08 OZ9AAR WSJT Log Viewer - Version 1.0.0.7

2026-06-27 OZ9AAR WSJT Log Viewer - Version 1.0.0.6

2026-06-25 OZ9AAR WSJT Log Viewer - Version 1.0.0.5

2026-06-22 OZ9AAR WSJT Log Viewer - Version 1.0.0.4

2026-06-18 OZ9AAR WSJT Log Viewer - Version 1.0.0.3

2026-06-17 OZ9AAR WSJT Log Viewer - Version 1.0.0.2

2026-06-16 OZ9AAR WSJT Log Viewer - Version 1.0.0.1

Release notes

2026-07-10 OZ9AAR WSJT Log Viewer - 1.0.0.8

• Fixed handling/resizing/loading of splitters on the tabs
  
• Added "Follow station live", if enabled, the program will switch to the callsign just received from WSJT and show data for that
  

2026-07-09 OZ9AAR WSJT Log Viewer - 1.0.0.7

• Optimized caching of loaded data, better indexes etc, result is higher speed on large files

• New function, can now create a list of initials (selected by band), list is simple text, can be copied to clipboard
  

2026-06-27 OZ9AAR WSJT Log Viewer - 1.0.0.6

• Even more optimization for data, views are now much faster than previously
  

2026-06-25 OZ9AAR WSJT Log Viewer - 1.0.0.5

• Optimized loading of big files, especially if used "live" (large files can still be slow due to the indexing and searching that is done)
  

2026-06-22 OZ9AAR WSJT Log Viewer - 1.0.0.4

• Live view added. Application will monitor the ALL.TXT file and update the views when decodes are done in WSJT, all live!
  
• Better alignment of the dots on the "RX SNR" and "Best SNR" graphs.
  

2026-06-18 OZ9AAR WSJT Log Viewer - 1.0.0.3

• Added "Reload file" menu item (Thanks Jim N8ECI)
  
• The last open file folder location is remembered (Thanks Jim N8ECI)
  

2026-06-17 OZ9AAR WSJT Log Viewer - 1.0.0.2

• Added 24 and 47GHz to bands (Thanks Ivan IZ0JNY)
  
• Fixed errors when using text scaling in Windows (Thanks Christian HB9DFG)
  
• Added 6m to bands (Thanks Peter VK5PJ)
  
• Changed GUI in a few places with regards to mouse clicks (single/double)

2026-06-16 OZ9AAR WSJT Log Viewer - 1.0.0.1

• Initial version