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FT8 Setup

VE6DOK · FT8 Setup

FT8 setup: get the radio, computer, audio, CAT control, and clock working together.

FT8 is not difficult once the pieces are understood, but it can be frustrating when one setting is wrong. This page walks through the setup in a practical order: radio, interface, software, audio levels, CAT control, time sync, and first decode.

Core idea: FT8 works only when timing, audio, radio control, and signal levels are all close enough. Most setup failures come from time sync, wrong sound device, wrong CAT settings, or overdriven audio.
FT8 Overview
FT8 Operating
Troubleshooting
Antenna Testing

What you need

Radio

HF transceiver

Any SSB-capable HF radio can be used if you can pass clean audio between the radio and computer. CAT control is strongly recommended.

Computer

Windows, Mac, or Linux

The computer runs WSJT-X or compatible software, handles decoding, generates transmit audio, and controls the radio if CAT is configured.

Interface

Audio + control path

Modern radios may have built-in USB audio and CAT. Older radios may need an external sound interface and serial/CAT cable.

Setup order that prevents confusion

Do not try to fix everything at once. Bring the system up in this order.

1. Install WSJT-X.
Install the software and confirm it opens before connecting everything else.
2. Confirm computer time sync.
FT8 depends on accurate timing. If your clock is off, you may see no decodes or failed contacts.
3. Select the correct sound devices.
Choose the radio/interface input and output devices, not the laptop microphone or speakers.
4. Configure CAT control.
Set rig model, serial port, baud rate, PTT method, and test CAT before transmitting.
5. Verify receive audio.
You should see signals on the waterfall and decodes in the receive window.
6. Verify transmit audio carefully.
Use low power at first, watch ALC, and avoid overdriving the radio.

Time synchronization: the first thing to check

FT8 uses timed transmit/receive cycles. If your computer clock is off by even a small amount, decoding and contacts can fail.

Symptoms of bad time sync

  • No decodes even when signals are visible
  • Other stations do not answer
  • Contacts start but do not complete

Practical fix

Use a reliable time-sync method and verify the clock before blaming the radio, antenna, or software.

Audio setup: clean audio matters

FT8 is generated as audio tones. If the audio is too low, too high, distorted, or routed through the wrong device, performance suffers.

Setting What to check Common mistake
Input device Radio/interface receive audio Computer microphone selected by accident
Output device Radio/interface transmit audio Laptop speakers selected by accident
Receive level Waterfall active but not overloaded Too low or clipping
Transmit level Clean output with little/no ALC action Overdriving audio and splattering
Operating standard: keep transmit audio clean. More audio drive is not better. A clean low-power FT8 signal is far better than an overdriven wide signal.

CAT control and PTT

CAT control lets the software read and change frequency, mode, and transmit state. It is not strictly required in every setup, but it makes FT8 much smoother and reduces operator errors.

CAT control does

  • Tracks radio frequency
  • Sets mode and band
  • Can control transmit/receive switching

PTT options

  • CAT PTT
  • VOX
  • Serial interface PTT
  • Radio-specific USB control

Radio settings checklist

Mode: use USB/data mode as appropriate for your radio.
Power: start low. FT8 is efficient and does not usually require high power.
Compression: turn speech processing/compression off for digital audio.
Filters: use a filter wide enough for the FT8 passband.
ALC: avoid heavy ALC movement. Overdriven audio creates a poor signal.

First-decode checklist

Before transmitting, prove that receive works.

  • Radio is on a common FT8 frequency for the band.
  • Computer time is synchronized.
  • Correct sound input device is selected.
  • Waterfall shows signals when the band is active.
  • WSJT-X decodes callsigns and signal reports.
  • Frequency and band shown in software match the radio.

First transmit checklist

  • Start at low RF power.
  • Confirm antenna is suitable and matched.
  • Watch ALC and audio drive.
  • Use a clear frequency on the waterfall.
  • Make one test contact before changing multiple settings.
Do not troubleshoot by changing ten settings at once. Change one thing, test, and observe.

Where setup problems usually come from

Time

Clock sync

No decodes or missed contacts often trace back to timing.

Audio

Wrong device or level

The most common setup issue is selecting the wrong input/output or overdriving audio.

Control

CAT/PTT mismatch

Wrong port, wrong baud rate, or wrong PTT method can stop transmit control.

RF

RF feedback

RF in the shack can crash audio, USB, CAT, or computer stability.

Antenna

Weak system

FT8 can work with modest antennas, but antenna problems still limit results.

Power

Too much drive

Running too much audio or RF power can create a poor signal and reduce success.

Next steps

FT8 Operating

Learn how to call CQ, answer, complete exchanges, and log contacts.

FT8 Troubleshooting

If setup does not work, use the troubleshooting page before changing everything.