For WSJT-x AND JTDX

Use Hamilton Auto FT8 with JTDX

June 18, 2026

Hamilton Auto FT8 runs the full FT8 contact sequence inside JTDX — hear the CQ, call the station, exchange reports, confirm 73, and log the contact, all automatically. This guide takes you from download to your first hands-free QSO using JTDX as the engine. If you’re a DXer who prefers JTDX’s sharper decoder, this is your path.

Important · Read before operating

Hamilton automates the FT8 contact sequence — it does not relieve you of your duty as control operator. Stay at the radio while it runs. Be ready to stop transmitting immediately if interference or any regulatory issue occurs. Think of Hamilton like autopilot, not auto-driver.

What you need

  • Windows 10 or Windows 11 (64-bit) — Hamilton Auto FT8 is Windows-only
  • JTDX already working with your radio (audio chain, CAT, PTT all tested and operational)

Step 1 — Download and install Hamilton Auto FT8

  1. Go to autoft8.com/downloads
  2. Click the green Download button for Hamilton Auto FT8
  3. Run Hamilton_Auto_FT8_Setup_1.0.62.exe
  4. If Windows shows a blue “Windows protected your PC” screen, click More info → Run anyway
  5. Click through the installer and click Finish

Hamilton’s window will open. Don’t click Start yet — JTDX needs configuration first.

Step 2 — Configure JTDX (Reporting tab)

  1. Open JTDX
  2. File → Settings
  3. Click the Reporting tab
  4. Set UDP Server to 127.0.0.1
  5. Set UDP Server port to 2237
  6. Check Accept UDP requests
  7. Check Notify on accepted UDP request

Step 3 — Configure JTDX (Behavior tab) — where JTDX differs

  1. Click the Behavior tab
  2. Set Auto Sequencing to mode 3 (Call based on end of decoding)
  3. Check RR73 to log (closes the QSO and triggers logging)
  4. Check Decode all signals in receive bandwidth
  5. Leave Tx watchdog at default, or raise to 5+ minutes
  6. Click OK and completely close and reopen JTDX

Critical · JTDX has TWO Auto Seq controls — both must be active

This is the #1 reason new JTDX + Hamilton users get stuck. WSJT-X has one Auto Seq checkbox; JTDX has two.

1. Settings → Behavior tab → “Auto Sequencing” dropdown set to mode 3. This configures the BEHAVIOR but doesn’t switch sequencing on.

2. The “Auto Seq” checkbox at the bottom of the JTDX main window. Not in Settings — on the main UI itself. This is the master ON switch.

If you set mode 3 in Settings but leave the main-window checkbox unchecked, JTDX accepts Hamilton’s initial call but gets stuck on message 1 and never advances. Both must be active.

Step 4 — JTDX main window checkboxes

At the bottom of the JTDX main window:

  • Auto Seq — CHECKED (master ON switch — read the callout above)
  • Call 1st — unchecked (when checked, it conflicts with Hamilton’s filters)
  • Hold Tx Freq — your preference (doesn’t affect Hamilton)
  • Tx even/1st — your preference (controls TX time slot)

Step 5 — Start in the right order

  1. Start JTDX first and confirm decodes are flowing and PTT works (briefly press Tune)
  2. Then click Start in Hamilton

Within 5 seconds, Hamilton’s activity feed should show:

  • UDP proxy listening on 127.0.0.1:2237
  • Translating UDP id: 'JTDX' to 'WSJT-X' — this is normal; Hamilton’s UDP proxy translates JTDX’s id so its internal contact manager accepts the packets
  • Engine UDP confirmed
  • Listening for JTDX — ready to make contacts

Hamilton is now running. When a callable station appears in JTDX’s decodes, Hamilton picks it, drives JTDX through the exchange, and closes the QSO at RR73.

Optional — CQ when idle

Same as WSJT-X — click CQ when idle in Hamilton and pick Hunter or Activator mode. Hamilton drives JTDX’s Enable Tx automatically.

Optional — QRZ Logbook auto-submission

  1. QRZ.com → Logbook → Settings → copy your Logbook API Key
  2. Hamilton → Settings → QRZ Logbook → paste the key → Save

Troubleshooting

JTDX replies but gets stuck on message 1

The classic JTDX problem. The Behavior tab dropdown and the main window Auto Seq checkbox must both be active. See the callout in Step 3.

Hamilton says it’s running but never calls anyone

  1. Accept UDP requests checked in JTDX Reporting tab? (Restart JTDX after enabling)
  2. Auto Seq checked at the bottom of JTDX’s main window?
  3. Enable Tx on JTDX’s main window lit?
  4. Filter file too strict? Check Hamilton’s Settings → Advanced → Filter file path

“Address already in use” error

Another program owns port 2237 — JTAlert, GridTracker, an old Hamilton, or a second JTDX/WSJT-X instance. Close them and try again.

You’re done

JTDX first (with both Auto Seqs active), Hamilton second, click Start.

Download Hamilton Auto FT8 free at autoft8.com/downloads. Stuck? Email support@autoft8.com.

73 and good DX.