04 · Digital Modes
Integration with WSJT-X and JTDX — FT8, FT4, JT65, WSPR and more
Integration Architecture
RadioLog integrates with WSJT-X and JTDX transparently through two independent channels:
- UDP — WSJT-X automatically sends confirmed QSOs to RadioLog (port 2237).
- CAT relay — RadioLog shares radio control with WSJT-X via the Hamlib NET rigctl protocol (TCP port 4532).
Configuring WSJT-X — Step by Step
Step 1 — UDP (automatic QSO saving)
- In WSJT-X: File → Preferences → Reporting
- Enable ☑ Accept UDP requests
- UDP server:
127.0.0.1| Port:2237
From this point, every QSO you confirm in WSJT-X will be saved automatically to the RadioLog logbook.
Step 2 — CAT relay (frequency control)
- In WSJT-X: File → Preferences → Radio
- Rig: Hamlib NET rigctl
- Network server:
localhost| Port:4532 - Do not configure any serial port — RadioLog controls the radio.
- Click Test CAT. «CAT: OK» should appear in green.
Step 3 — PTT (radio keying)
For WSJT-X to transmit it needs PTT control. The recommended method is RTS on the second virtual COM port of the radio (the PTT/Enhanced port, different from the CAT port).
| Radio | CAT port (RadioLog) | PTT port (WSJT-X) |
|---|---|---|
| Yaesu FTDX10 | COM3 (CAT) | COM4 (PTT/Enhanced) — RTS |
| Yaesu FT-991A | COM3 (CAT) | COM4 (PTT/Enhanced) — RTS |
| Yaesu FT-710 | COM3 (CAT) | COM4 (PTT/Enhanced) — RTS |
| Icom IC-7300 | COM3 (CI-V) | COM4 (PTT) — RTS or VOX |
Step 4 — RadioLog Configuration
In RadioLog: Settings → Digital Modes
Recommended Startup Order
- Power on the radio
- Launch RadioLog — connects CAT automatically
- Launch WSJT-X — connects to the relay and log automatically
WSJT-X can start before RadioLog without issue — it will retry the connection automatically.
FT8 QSO Flow
- WSJT-X receives and transmits according to the FT8 protocol.
- When you complete a QSO in WSJT-X, WSJT-X sends it via UDP to RadioLog.
- RadioLog receives it, adds DXCC, continent and CQ zone from the local prefix file (cty.dat) and saves it to the logbook automatically.
- In the RadioLog main window you will see the new QSO without having entered anything manually.
Configuring JTDX
The process is identical to WSJT-X. JTDX also uses the WSJT-X UDP protocol for logging and Hamlib NET rigctl for the CAT relay. The same ports (2237 for UDP, 4532 for CAT) work with both programs. Do not use both at the same time with the same radio.
FLDigi Integration
FLDigi can connect to RadioLog's CAT relay at localhost:4532. For automatic logging from FLDigi, see the FLDigi documentation for XML-RPC or UDP integration. This integration is under development in RadioLog.
Verifying Everything Works
Indicators in the RadioLog main window:
- VFO block: 🟢 CAT — radio connected. 🔴 CAT — no connection.
- Status bar (temporary message): «WSJT-X: WSJT-X connected» — appears when the first WSJT-X heartbeat is received. The UDP listener is active from RadioLog startup; no action needed.