https://www.physics.princeton.edu/pulsar/K1JT/wsjtx.html

WSJT-X
Click File, then click Settings.
In the new window that opens, click the General tab and enter your call in the My Call text box.
Click the Radio tab and select "None" in the Rig drop-down menu.  Select "Vox" as the PTT Method.  Note that your radio's VOX setting should be OFF.  This setting simply allows the SignaLink USB to control PTT
Click the Audio tab and select "USB Audio Codec" for both the Input and Output sound card.  If using Windows Vista/7/8.x/10, then you'll need to select  "Microphone - USB Audio Codec" for "Input" and "Speakers - USB Audio Codec" for "Output".
Click the OK button to close the Settings window.
Set the "PWR" slider on the WSJT-X main window (right-hand side of screen) to the second notch from the top (roughly -5.1db).  Note that if you lower this slider too much the SignaLink USB will NOT switch into transmit!  See details below.
WSJT-X is a complex program so please take some time to read the WSJT-X users guide!

Notes / Tips

The WSJT-X "PWR" slider can be lowered from the above recommended setting if adjustment of the SignaLink's TX knob is touchy.  However, it should be understood that the "PWR" slider directly affects the Window's Playback "Application" level slider for the SignaLink's sound card, so lowering it too much will prevent the SignaLink's PTT circuit from activating.  A PWR slider setting of roughly -5.9db is about equal to the normally recommended setting of 50% on the "Application" slider, and you can lower the PWR slider to around -18db before PTT stops working.  We would recommend that you keep the PWR slider at least a couple db above this threshold so that PTT activates reliably.

Your computer's clock MUST be synchronized using a free clock synchronizing utility or you will be unable to make any contacts.  See the WSJT-X website for details. 

The SignaLink doesn't handle CAT / CIV control, so if you want to use the CAT / CIV rig control feature offered by WSJT-X, then you MUST have a separate CAT / CIV interface cable connected between your computer and radio.  You will need to configure the various CAT / CIV parameters on the "Radio" tab according to your radio manual and/or the instructions provided with your CAT / CIV interface.

If applicable to your radio (some options may be grayed out), the "Transmit Audio Source" setting should be set to "Rear/Data" if the SignaLink is attached to your radio's Data or Accy Port.  Otherwise, if applicable to your radio, it should be set it to "Front/Mic".  Also, if applicable to your radio, the "Mode" selection should be set to "Data/Pkt" if your radio provides a "Data" type mode and the SignaLink is attached to the radio's Data or Accy Port.  Otherwise, if applicable to your radio, the "Mode" selection should be set to "USB" or "None".

The PTT Method MUST be set to VOX if the SignaLink is attached to the radio's Data or Accy Port.  If the SignaLink is attached to your radio's Microphone jack then you can use the "CAT" PTT option if you prefer.

 Please note that Tigertronics does not provide support for CAT / CIV interfaces.  You will need to refer to your radio manual and/or the instructions provided with your CAT / CIV interface.
TOP