WSJT-X 3.0: What Is New for FT8 and Weak-Signal Operators
WSJT-X is the program behind most FT8 contacts in the world, and each major release changes the way many operators work. This guide walks through WSJT-X 3.0 as described in the version 3.0.0 User Guide on the project site. It covers the features that change daily operation (band buttons, filters, the Wait features and audible alerts), the technical additions (parallel FT8 decoding, full duplex mode, the Transceiver Control Interface and the SWR cutoff), and what to check before you upgrade. I use only what the documentation says, so if you run a different version, compare with its own guide.
Where the New Version Comes From
The WSJT-X 3.0.0 User Guide begins with an introduction explaining that WSJT-X is an open-source program designed to facilitate basic amateur radio communication using very weak signals. The name stands for Weak Signal communication by K1JT, and the program started as an extended branch of the earlier WSJT, first released by Joe Taylor, K1JT, in 2001. The guide credits a long list of contributors, including the core development team, and states that WSJT-X provides flexible rig control for nearly all modern radios, automatic Doppler tracking for EME and lunar echo testing, and analysis of received passbands up to 5 kHz wide on Windows, Macintosh and Linux. The installer filenames in the guide include wsjtx-3.0.0-win64.exe for 64-bit Windows.
The guide also explains the version numbering: major, minor and patch numbers separated by periods, with release candidates such as 2.7.0-rc1 issued ahead of a general-availability release, and a rule that release candidates should be used only during a defined testing period and not on the air after the general-availability release with the same number. That is useful advice for anyone tempted to run pre-release software during a contest.
What Is New in Version 3.0
The section “New in Version 3.0” lists the main developments, which I summarize here in the order the guide gives them. The table groups them by what they change for the operator.
| Feature | What it does | Who benefits |
|---|---|---|
| Band Buttons | Two sets of buttons from the View menu: an HF set for 160 m through 70 cm and a VHF-and-up set for 8 m through 24 GHz | Everyone who changes bands often |
| Parallel FT8 decoding | Option for up to a dozen concurrent threads, for improved performance | Busy bands and slower computers |
| Filters | Hide, ignore or highlight categories such as stations worked before on the band, today or yesterday | Contesters and DXers |
| Wait features | Wait and Reply, Wait and Call, Wait and Pounce | Operators in poor propagation |
| Audible Alerts | A sound when a message with specified content is decoded | Chasers who do not watch the screen |
| Full Duplex Mode | Transmit and receive at the same time | Satellite operators |
| TCI support | Transceiver Control Interface for rig control and audio | Owners of SDR radios that offer it |
| Transmitted power and SWR | Shown on the status bar, with an automatic stop if SWR exceeds 2.5 | Anyone who switches antennas |
Band Buttons and the Interface
Band Buttons can be enabled from the View menu, and the guide says they appear as a top row of controls under the decoded text windows. Two sets are available. One is oriented to HF and covers the bands from 160 meters to 70 centimeters; the other covers VHF and higher, from 8 meters to 24 GHz. Clicking a button changes the dial frequency, which is a faster alternative to opening the frequency list or typing on the radio. Combined with a logging program that follows the radio, it takes the guesswork out of band changes during a contest or a DX chase.
The guide also notes improvements for large screens: high-resolution monitors are supported with better scaling of fonts and widgets, and the user interface is available in many languages. You can start WSJT-X in a particular language from a command prompt, for example with wsjtx –language es for Spanish or –language ja for Japanese. OpenSSL is now installed automatically with WSJT-X, with manual intervention needed only if an incompatible version is already on the computer.
Filters: Hide What You Do Not Need
Filters limit what is displayed in the Band Activity window. You define filtering categories on the Filters tab of the settings, and you can switch many of them on or off from the Filters menu of the main window. According to the guide you can specify up to four territories for which hiding messages can be switched on or off, hide messages from a specific continent, or hide stations worked before on a band. There are entry fields for a Blacklist, a Whitelist and an Always Pass list, and they can be used in combination.
- Blacklist: suppress decodes from unwanted stations, contest messages or other unwanted content. You can enter whole callsigns, parts of callsigns or keywords.
- Whitelist: show only messages with certain grids, calls or keywords. Everything else is suppressed, except what the Always Pass list allows.
- Always Pass: display decodes from specific stations even if their country or continent is hidden.
- Ignore List: a click on the Ignore button adds the callsign in the DX Call box to the list, and such stations are ignored when you use the CQ options or Wait and Reply.
When any filter that limits the display is active, the status label changes from green “Receiving” to cyan “Receiving, Filters on”, so you do not forget that something is hidden. The guide adds that filters are disabled automatically for special operating modes, so you do not miss a station by accident, and that a BP (bypass) checkbox shows all decoded messages. If you currently use outside tools to filter decodes, compare them with our guides to GridTracker and JTAlert, which add maps and wanted-DXCC alerts on top of WSJT-X.
The Wait Features
Version 3.0 offers three wait-to-transmit features: Wait and Reply, Wait and Call and Wait and Pounce. You enable them with a checkbox near the bottom of the General settings tab. When they are enabled, the DX Call field and the Enable Tx button turn yellow to warn you that an automatic transmission may occur when a specified condition is met. The guide tells you to be alert and take any necessary precautions.
Wait and Reply continues your QSO when the station in the DX Call field sends you a message. For example, you may have called K1ABC, received no reply and stopped transmitting when K1ABC answered someone else; if K1ABC then calls you, your QSO resumes automatically, and a second RR73 is sent if your first one was not answered. It works in all modes where auto-sequencing is available. The guide suggests clearing the DX Call field after each QSO, using the F4 key or a right-click on the DX Call button.
Wait and Call is for a station that disappears in a deep fade. When you click the DX Call label, which turns red if a callsign is present, the program calls the station automatically up to three times after decoding it again sending CQ, RR73, RRR or 73. Pressing Halt Tx or Stop disables it.
Wait and Pounce answers a CQ from a station that meets selection criteria. With the DX Call box empty, you choose a CQ category from the drop-down list, right-click Enable Tx so that it turns orange, and in your next transmit sequence the program replies to a CQing station that matches. With Max Dist, Max dB or Min dB the program prevents working dupes by consulting the wsjtx.log file; the guide warns not to erase the file wsjtx_log.adi, which is your primary logbook. Wait and Pounce works together with the filters, so you can wait for a particular prefix, grid, callsign or keyword.
Remember that the wait features do not remove the human from the loop. The guide says clearly that auto-sequencing is an operator aid, not an operator replacement, and that WSJT-X will not make consecutive fully automated QSOs. Some contests and awards also require attended operation, so check the rules; our FT8 DXpedition mode guide explains related behavior with Fox and Hound stations.
Audible Alerts
WSJT-X can play a sound when a decoded message has specific content. This requires access to at least two audio output devices: one for the transmitted audio, selected on the Audio tab, and a different one for alerts, which are always played on the default audio device, usually the computer’s speaker. You turn on alerts by checking the desired boxes on the Alerts menu and clicking Enable Audio Alerts. Categories above the dividing line in the menu need the option to show DXCC, grid and worked-before status to be enabled on the General tab, and the Colors tab shows what triggered an alert. A callsign in the Ignore list is silent unless you check BP, and you can mute the alerts for one callsign with a click on the Ignore button.
Full Duplex, TCI and the SWR Cutoff
Full Duplex Mode lets WSJT-X transmit and receive at the same time. The guide says it is useful for satellite operation, where the audio source is normally set to the transponder downlink, and for monitoring your own transmitted signal by using a web SDR as the audio input. The Transceiver Control Interface (TCI) is a software layer that allows control, data transfer and synchronization between hardware devices and applications, and WSJT-X 3.0 supports it for both rig control and audio input and output.
Transmitted power and SWR can now be displayed in a status bar label, as reported by the radio, and transmission can be stopped automatically if the SWR exceeds 2.5, for example if you accidentally select the wrong antenna. The guide says these features work with most modern radios controlled through Hamlib or FLRig. Our guide to rig control with Hamlib explains the control path, and the Hamlib project is where radio support is developed. A right-click on the Tune button can also start ATU tuning on some radios with an internal ATU, again through Hamlib.
Other Additions Worth Knowing
- Band hopping for FT8, FT4 and MSK144: checkboxes allow sequential reception intervals on the main sub-bands, or on up to eight dial frequencies that you specify.
- Saved audio: files can be set to delete automatically after 30 days, which keeps disk usage under control.
- Features for all QSO modes: auto-sequencing, filters, reply-to-CQ and the wait features are available for the 72-bit modes JT4, JT9 and JT65 as well as the 77-bit modes FST4, FT4, FT8, MSK144 and Q65.
- SuperHound and SuperFox: SuperHound operators can activate Wait and Call for a SuperFox callsign even if SuperFox has not yet been decoded, but blind calling is prevented; Fox operators get a warning if another Fox seems to be on the same frequency.
- EME improvements: easier selection of dial frequencies within an EME sub-band, offsets of an integer number of megahertz between transmit and receive, buttons for Echo mode and six popular Q65 submodes, and CALL3.TXT downloads.
- Logging: support for an ADIF field type for satellite QSOs and a “Log automatically” option when not in contest mode.
Before You Upgrade
- Back up your log and settings. Copy wsjtx_log.adi and your configuration before installing.
- Read the system requirements. The 3.0 guide lists a computer with a modern Windows, macOS or Linux, audio at 48000 Hz and 16 bits, and a way to synchronize the clock to UTC within one second.
- Do not upgrade the day before a contest. Test the new interface and your rig control first.
- Re-check your setup. Our WSJT-X and FT8 setup guide lists the audio, CAT and clock settings to verify after any change.
- Try the new features one at a time. Enable filters first, then alerts, then the wait features, and notice how each changes your operating.
The Bottom Line
WSJT-X 3.0 adds quality-of-life features that matter every day: band buttons, flexible filters, wait options that save you from useless transmissions, audible alerts and an SWR cutoff that protects the transmitter. It also adds technical features for specialists, including full duplex, TCI, band hopping and EME improvements. Read the relevant sections of the guide, back up your files, and adopt the features gradually so that you stay in control of every contact.
Frequently Asked Questions
What are the Wait features?
Wait and Reply, Wait and Call and Wait and Pounce are options that help you make QSOs under difficult propagation conditions while minimizing useless transmissions. Enabled features turn the DX Call field and Enable Tx button yellow.
Can WSJT-X 3.0 stop transmitting if the SWR is high?
Yes. Transmitted power and SWR can be shown in the status bar, and transmission can be stopped automatically if SWR exceeds 2.5, with most radios controlled through Hamlib or FLRig.
What are the band buttons?
Two sets of buttons, enabled in the View menu: one for HF from 160 m through 70 cm, and one for VHF and up from 8 m through 24 GHz.
Do audible alerts need special hardware?
They need at least two audio output devices: one for transmitted audio and the default device for the alerts.
Is the interface available in other languages?
Yes. The user interface is available in many languages, and you can start the program in a chosen language with a command line option.
Does 3.0 still support the older modes?
Yes. The guide lists JT4, JT9 and JT65 together with FST4, FT4, FT8, MSK144, Q65, WSPR, FST4W and Echo mode.