WSJT-X for Dummies & Experts

An Amateur Radio Program for Decoding Weak Signals


WSJT-X is a digital software program for amateur radio operators. If you already have the equipment to run PSK or RTTY, then you have all you need.  

This site attempts to simplify its setup and use on the amateur bands. It is designed to complement, not to take the place of the program's documentation. The program's documentation is a must read if you want to be sucessful in using WSJT-X.  

You can find the official WSJT-X documentation: HERE.

New Block

A note on the use of non-standard exchanges: RR73:

It is becoming common to use a grid message with a bogus grid RR73 to try and complete a QSO very quickly. This creates a few issues, not least of which is if you double-click such a message you will not send the correct next message, nor will you log the right grid for your QSO partner. You must manually select the correct message to send next and click the "Log QSO" button if you are happy the QSO is complete.

While this isn’t a problem on HF (but is still invalid data), on VHF it is a huge problem as grid squares are important data there.  If you are calling CQ and you're in a hurry, sending RRR and then CQ again, will let the other person know that the QSO is complete.  If instead you were replying to someone who called CQ, then send 73 to let them know you have received their RRR.

NOTE: presently the WSJT-X developers are updating the software in order to utilize RR73 as an optional sign off message.  This will still permit auto sequencing.

Who's on First, and What's on Second?

Should you transmit first, or second?  On HF, it's not an issue, however on VHF bands such as 6 meters, you don't want to transmit at the same time the other station is transmitting.  The un-official standard agreed to by users of the ON4KST site, is for users in the USA to transmit second, and those in EU to transmit first.

CTY.DAT file:

WSJT-X has a built in copy of the standard format CTY.DAT file that can be downloaded from the web (, this only gets updated by new WSJT-X releases. Because this data is subject to change WSJT-X also allows users to install a fresh copy of CTY.DAT, all that is necessary is to put the new file into the WSJT-X log directory.