Announcing JT-Mapper: Real-time JT65 and JT9 Maps

When you run JT9 and JT65 using WSJT-X, have you ever wondered where in the world all those stations you are hearing are?

Carl, WG1V certainly has, which is why he wrote a little R program to map them all in real-time. That tool is called JT-Mapper, and if you’re running WSJT-X on a Mac or Linux, he’d love for you to give it a try and let him know what you think of it.

First a few caveats for those brave souls who want to give this a shot:

  • You have to be running WSJT-X on a Mac or Linux machine. Windows machines lack an essential utility for the program to work, so he is deferring Windows support.
  • You have to install the open source language R on your computer and download a bunch of libraries for it. This is no big deal, but Carl wants people to know that this is not just download and go. R language installers are available at
  • You have to be comfortable typing at the command line to start up the program (or be comfortable sourcing it from R itself).

For anyone wanting to see what this looks like, you can check out Carl’s public repository on github. The document there has screen shots and many more details about the program. You can read about it and download the program (cleverly named JT-Mapper.R) at:

Carl has a full time job and travels a fair amount for work, so while he is happy to answer the occasional question, please be patient — it can be days before he is able to answer.

Finally, Carl would like to thank Joe Taylor, whose WSJT-X program inspired him to write this code. Carl writes a lot of visualizations as part of his big data work, and he says that it was a treat to be able to apply this to ham radio through his software. Thank you Joe.

Have fun,