The basic requirements for WSJT operation are a PC (Pentium 75 or greater, 24Mb RAM, 40Mb free disk space), a monitor with 800x600 or higher resolution, a Windows compatible sound card and Microsoft Windows 95/98/ME/NT/2000/XP. Also required is a simple computer-to-radio interface. These interfaces also support PSK31, SSTV, RTTY etc and are available commercially from suppliers such as West Mountain Radio, Buxcommco and MFJ. Alternatively the instructions for assembling this interface can be found on the Projects Page of this site. The software is available free of charge at the home page of the author, Joe Taylor K1JT, or from the WSJT Download Page on this site!.


1. Install and launch WSJT Software.
2. Click SETUP/SET COMM PORT and put in the serial port you are using.
3. Next click SETUP/OPTIONS
4. In options page put in:
   MY CALL = your call sign
   GRID LOCATER = your 6 digit grid locator (Put in you grid like this KG33xx not KG33XX)
   UTC OFFSET = leave at zero (default) to have WSJT display local time, or put in your UTC
        difference to have it display UTC time in WSJT software. Best to put in for UTC
        time so the new JT44 mode moon tracking will work correctly.
   TX MESSAGE FORMAT = use North America settings: click on NA DEFAULTS
   TONE AMPLIFIERS = you can leave the A-B-C-D defaults at 1.000 if all 4 of your WSJT
        tone levels put out the same power out. Test by using TUNE
        A-B-C-D buttons on WSJT software below TX STOP button. If these do not each give
        the same power out, then click here.
   FREQ MHZ = If you will be doing JT44 EME then you need to put in the freq mhz for the band you
        you will be using so that JT44 will display correct doppler etc for that band.
AUDIO OUTPUT = You can select left-right-both which will allow you (depending on your setup) to not
        have to hear your xmit audio while you are transmitting. You can just leave on "both" if in doubt.

Click DONE and exit OPTIONS page. Select the mode in which you wish to operate (FSK441 / JT44) under the MODE menu.

5. Set your receive noise level to 0db in the WSJT software. Put the software into MONITOR mode with your radio connected and monitoring a clear channel (listening to "white noise"). Look at the very bottom in the middle of the WSJT window. It will indicate the receive noise level there at the end of the period. You can adjust it to 0db by using the soundcard mixer, activated by WSJT SETUP/ADJUST RX VOLUME CONTROL. Additionally if you are using the Mic/Ext speaker connection method for your interface you can adjust the level via your radio AF control. If you are using an Auxiliary Port for interfacing then AF will remain fixed. Make sure in the mixer that your LINE IN is not muted and use the sliders there to adjust to get your 0db receive noise level.

6. Next you need to test to be sure you are not overdriving tour rig audio input. This can be controlled by your Mic Gain control ( if you are feeding your sound card output into rig mic input )or alternatively via the soundcard mixer, activated by WSJT SETUP/ADJUST TX VOLUME CONTROL if you are using an auxiliary input to the rig. Use the WAVE slider to adjust the TX gain. Also be sure you Mixer/ WAVE does not have the Mute box checked.

7. Now that the software is all setup you are ready to run a sked. To run a sked with a station you need to put
in THEIR CALL SIGN in "To Radio" box, and Check or Un-Check "TX First" depending on if you are the
Northern-most station. Northern stations always use first period. If using FSK441 then check "Single Tone Msgs"and set the required period - normally 15 seconds on 6m, 30 seconds on 2m. In JT44 select "zap birdies" if you suffer from birdie interference, and EME Msgs if you are running an EME sked.

8. Click on AUTO PERIOD OFF to change it to AUTO PERIOD ON to start running the sked. This will trigger
the WSJT software to start the automatic T/R sequencing.

For further assistance look at WB5APD's Personal Notes on Rig & Software Setup.

Both FSK441 and JT44 require time synchronisation between the transmitting and receiving stations. You will need a method of setting your computer clock to an accuracy of 1 second or better, and keeping it set. You may choose to set the computer clock manually to WWV or another broadcast time service, but this procedure can be cumbersome and you will have to watch it carefully. The most popular method of synchronisation is via an internet clock-setting program. Dimension 4 works very well, and can be downloaded here. This archive includes PDF files detailing setup. Other timesetting utilities are also available on the Software Downloads page.