Setting Up WSJT-X Software for FT8 Operation on a Yaesu 991A
WSJT-X is the software used for FT8 and other weak-signal digital modes. Proper configuration is essential for reliable decoding, clean transmission, and correct CAT control of your radio. This guide walks through configuring WSJT-X for FT8 operation using a Yaesu FT-991 series radio and USB CAT/audio.
Step 1: Download and Install WSJT-X
- Download WSJT-X for Windows from the official WSJT-X website.
- The same page also provides installers for Linux and macOS.
- Install the software using the default options.
- Refer to the online WSJT-X manual if additional help is needed.
Step 2: Open WSJT-X Settings
- Launch WSJT-X.
- Click File → Settings….
- The Settings window will open with several configuration tabs.
Step 3: General Tab Settings
On the General tab, enter your station information.
- My Call: N5AJY (replace with your own call sign)
- IARU Region: Region ALL
- My Grid: EM26CD (enter your six-character grid square)
In the Display and Behavior sections, you may leave the defaults for now. The following options are commonly enabled and can be adjusted later as you become familiar with WSJT-X:
- Blank line between decoding periods
- Double-click on call sets Tx enable
- Tx messages to Rx frequency window
- Disable Tx after sending 73
- Show DXCC, grid, and worked-before status
- Calling CQ forces Call 1st
Step 4: Radio Tab Settings
Click the Radio tab and configure CAT control.
- Rig: Yaesu FT-991
- Serial Port: Select the COM port shown in Device Manager (example: COM3)
- Baud Rate: 9600
- Data Bits: Eight
- Stop Bits: Two
- Handshake: Default
- PTT Method: RTS
- Port: COM 3 or 4 usually
- Mode: USB
- Split Operation: Non
Use the Test CAT and Test PTT buttons to verify communication between WSJT-X and the radio.
Step 5: Audio Tab Settings
Click the Audio tab and select the FT-991 USB audio device.
- Input: Microphone (2 – USB Audio CODEC)
- Output: Speakers (2 – USB Audio CODEC)
These selections route receive audio from the radio to WSJT-X and transmit audio from WSJT-X back to the radio via USB.
Step 6: Final Checks
- Click OK to save settings.
- Tune the radio to an FT8 frequency (example: 14.074 MHz).
- Verify that signals decode in the WSJT-X waterfall.
- Transmit briefly and confirm proper PTT operation.
- Adjust transmit audio so there is no ALC indication on the radio.
Operating Tips
- Always verify your computer clock is accurate (within 1 second).
- Use modest power levels (typically 10–30 watts).
- Keep transmit audio clean and avoid ALC.
- Only allow one application to control CAT at a time.
Once WSJT-X is configured correctly, FT8 operation becomes reliable and repeatable. Combined with proper radio setup, this software configuration will give you clean, stable digital operation on all supported bands.