WSJT-X 2.0 User Guide

New FT8 and MSK144 protocols with 77-bit payloads permit these enhancements:

Improved color highlighting of received messages

Improved WSPR sensitivity

Expanded and improved UDP messages sent to companion programs

Bug fixes and other minor tweaks to user interface

Install WSJT-X into its own directory, for example C:\WSJTX or ` C:\WSJT\WSJTX`, rather than the conventional location C:\Program Files (x86)\WSJTX.

All program files relating to WSJT-X will be stored in the chosen installation directory and its subdirectories.

Logs and other writeable files will normally be found in the directory

The built-in Windows facility for time synchronization is usually not adequate. We recommend the program Meinberg NTP (see Network Time Protocol Setup for downloading and installation instructions) or Dimension 4 from Thinking Man Software. Recent versions of Windows 10 are now shipped with a more capable Internet time synchronization service that is suitable if configured appropriately.

From this version onward WSJT-X requires the OpenSSL libraries to be installed. Suitable libraries may already be installed on your system, if they are not you will see this error shortly after startup. To fix this you need to install the OpenSSL libraries.

WSJT-X expects your sound card to do its raw sampling at 48000 Hz. To ensure that this will be so when running under recent versions of Windows, open the system’s Sound control panel and select in turn the Recording and Playback tabs. Click on Properties, then Advanced, and select 16 bit, 48000 Hz (DVD Quality). Switch of all audio enhancement features for these devices.

You can uninstall WSJT-X by clicking its Uninstall link in the Windows Start menu, or by using Uninstall a Program on the Windows Control Panel Programs and Features option or in Settings Apps on Windows 10.

32-bit: wsjtx_2.0.1_i386.deb

64-bit: wsjtx_2.0.1_amd64.deb

64-bit: wsjtx_2.0.1_armhf.deb

32-bit: wsjtx-2.0.1-i686.rpm

64-bit: wsjtx-2.0.1-x86_64.rpm

Use the Mac’s Audio MIDI Setup utility to configure your sound card for 48000 Hz, two-channel, 16-bit format.

Use System Preferences to select an external time source to keep your system clock synchronized to UTC.

To uninstall simply drag the WSJT-X application from Applications to the Trash Can.

Select your radio type from the drop-down list labeled Rig, or None if you do not wish to use CAT control.

Set Poll Interval to the desired interval for WSJT-X to query your radio. For most radios a small number (say, 1 – 3 s) is suitable.

CAT Control: To have WSJT-X control the radio directly rather than though another program, make the following settings:

PTT Method: select VOX, CAT, DTR, or RTS as the desired method for T/R switching. If your choice is DTR or RTS, select the desired serial port (which may be the same one as used for CAT control).

Transmit Audio Source: some radios permit you to choose the connector that will accept Tx audio. If this choice is enabled, select Rear/Data or Front/Mic.

Mode: WSJT-X uses upper sideband mode for both transmitting and receiving. Select USB, or choose Data/Pkt if your radio offers such an option and uses it to enable the rear-panel audio line input. Some radios also offer wider and/or flatter passbands when set to Data/Pkt mode. Select None if you do not want WSJT-X to change the radio’s Mode setting.

Split Operation: Significant advantages result from using Split mode (separate VFOs for Rx and Tx) if your radio supports it. If it does not, WSJT-X can emulate such behavior. Either method will result in a cleaner transmitted signal, by keeping the Tx audio always in the range 1500 to 2000 Hz so that audio harmonics cannot pass through the Tx sideband filter. Select Rig to use the radio’s Split mode, or Fake It to have WSJT-X adjust the VFO frequency as needed, when T/R switching occurs. Choose None if you do not wish to use split operation.

Soundcard: Select the audio devices to be used for Input and Output. Usually the Mono settings will suffice, but in special cases you can choose Left, Right, or Both stereo channels.

Save Directory: WSJT-X can save its received audio sequences as .wav files. A default directory for these files is provided; you can select another location if desired.

AzEl Directory: A file named azel.dat will appear in the specified directory. The file contains information usable by another program for automatic tracking of the Sun or Moon, as well as calculated Doppler shift for the specified EME path. The file is updated once per second whenever the Astronomical Data window is displayed.

Remember power settings by band: Checking either of these will cause WSJT-X to remember the Pwr slider setting for that operation on a band-by-band basis. For example, when Tune is checked here and you click the Tune button on the main window, the power slider will change to the most recent setting used for Tune on the band in use.

To add a new message to the list, enter the desired text (up to 13 characters) in the entry field at top, then click Add.

To remove an unwanted message, click on the message and then on Delete.

You can reorder your macro messages by using drag-and-drop. The new order will be preserved when WSJT-X is restarted.

Messages can also be added from the main window’s Tx5 field on Tab 1 or the Free msg field on Tab 2. Simply hit [Enter] after the message has been entered.

Logging: Choose any desired options from this group. Operators in a multi-operator station may wish to enter their home callsign as Op Call.

Network Services: Check Enable PSK Reporter Spotting to send reception reports to the PSK Reporter mapping facility.

UDP Server: This group of options controls the network name or address and port number used by a program that will receive status updates from WSJT-X. Cooperating applications like JTAlert use this feature to obtain information about a running WSJT-X instance. If you are using JTAlert, be sure to check the three boxes at lower right.

N1MM Logger+ Broadcasts: To send information on logged QSOs directly to N1MM Logger+, check the box and enter the IP address and port number for N1MM.

To change an existing entry, double-click to edit it, type a desired frequency in MHz or select from the drop down list of options, then hit Enter on the keyboard. The program will format your changed entry appropriately.

To add a new entry, right-click anywhere on the frequency table and select Insert. Enter a frequency in MHz in the pop-up box and select the desired mode (or leave the Mode selection as All). Then click OK. The table may include more than one frequency for a given band.

To delete an entry, right-click it and select Delete, multiple entries can be deleted in a single operation by selecting them before right-clicking.

Right-click any entry and click Reset button to return the table to its default configuration.

To simplify things you might want to delete any unwanted bands — for example, bands where you have no equipment. Then click on a Frequency entry and type Ctrl+A to “select all,” and drag-and-drop the entries onto the Station Information table. You can then add any transverter offsets and antenna details.

To avoid typing the same information many times, you can drag-and-drop entries between the lines of the Station Information table.

When all settings have been configured to your liking, click OK to dismiss the Settings window.

WSJT-X uses colors to highlight decoded CQ messages of particular interest. Check the box Show DXCC, grid, and worked-before status on the Settings | General tab, and any boxes of interest to you on the Colors tab. You can drag any line up or down to raise or lower its logical priority. Right-click any line to set a new foreground or background color. Foreground and background colors are applied separately, and careful choices of foreground, background, and priority can provide two indications of worked-before status.

Press the Reset Highlighting button to reset all of the color settings to default values.

Check Highlight by Mode if you wish worked before status to be per mode.

Worked before status is calculated from your WSJT-X ADIF Logging file, you may replace ADIF log file with one exported from your station logging application, Rescan ADIF Log rebuilds the WSJT-X worked before indexes using the current ADIF log file.

Fetch Now will download a fresh dataset from the Users CSV file URL. The LoTW team normally update this data weekly.

Adjust Age of of last upload less than to set the period within which a station must have uploaded their log to LoTW to trigger highlighting.

Random erasure patterns logarithmically scales the number of pseudo-random trials used by the Franke-Taylor JT65 decoder. Larger numbers give slightly better sensitivity but take longer. For most purposes a good setting is 6 or 7.

Aggressive decoding level sets the threshold for acceptable decodes using Deep Search. Higher numbers will display results with lower confidence levels.

Check Two-pass decoding to enable a second decoding pass after signals producing first-pass decodes have been subtracted from the received data stream.

Set a positive number in Degrade S/N of .wav file to add known amounts of pseudo-random noise to data read from a .wav file. To ensure that the resulting S/N degradation is close to the requested number of dB, set Receiver bandwidth to your best estimate of the receiver’s effective noise bandwidth.

Set Tx delay to a number larger than the default 0.2 s to create a larger delay between execution of a command to enable PTT and onset of Tx audio.

Check x 2 Tone spacing or x 4 Tone spacing to generate Tx audio with twice or four times the normal tone spacing. This feature is intended for use with specialized LF/MF transmitters that divide generated frequencies by 2 or 4 as part of the transmission process.

Check this box and select the type of activity to enable auto-generation of special message formats for contesting and DXpeditions. For ARRL Field Day, enter your operating Class and ARRL/RAC section; for ARRL RTTY Roundup, enter your state or province. Use “DX” for section or state if you are not in the US or Canada. In the RTTY Roundup, Stations in Alaska and Hawaii should enter “DX”.

Check Fox if you are a DXpedition station operating in FT8 DXpedition Mode. Check Hound if you wish to make QSOs with such a Fox. Be sure to read the operating instructions for FT8 DXpedition Mode.

Click the Stop button on the main window to halt any data acquisition.

Select JT9 from the Mode menu and Deep from the Decode menu.

Set the audio frequencies to Tx 1224 Hz and Rx 1224 Hz.

Select Tab 2 (below the Decode button) to choose the alternative set of controls for generating and selecting Tx messages.

Select Download samples…​ from the Help menu.

Download some or all of the available sample files using checkboxes on the screen shown below. For this tutorial you will need at least the JT9 and JT9+JT65 files.

Bins/Pixel = 4

Start = 200 Hz

N Avg = 5

Palette = Digipan

Flatten = checked

Select Cumulative for data display

Gain and Zero sliders for waterfall and spectrum set near midscale

Spec = 25%

Use the mouse to grab the left or right edge of the Wide Graph, and adjust its width so that the upper frequency limit is about 2400 Hz.

Select File | Open and select the file ...\save\samples\JT9\130418_1742.wav. When the file opens you should see something similar to the following screen shot:

Click or double-click on either of the decoded lines highlighted in green. These actions produce the following results:

Double-click on the decoded message K1JT N5KDV EM41, highlighted in red. Results will be similar to those in the previous step. The Tx frequency (red marker) is not moved unless Shift or Ctrl is held down. Messages highlighted in red are usually in response to your own CQ or from a tail-ender, and you probably want your Tx frequency to stay where it was.

Click somewhere on the waterfall to set Rx frequency (green marker on waterfall scale).

Shift-click on the waterfall to set Tx frequency (red marker).

Ctrl-click on the waterfall to set both Rx and Tx frequencies.

Double-click on a signal in the waterfall to set Rx frequency and start a narrow-band decode there. Decoded text will appear in the right window only.

Ctrl-double-click on a signal to set both Rx and Tx frequencies and decode at the new frequency.

Click Erase to clear the right window.

Double-click Erase to clear both text windows.

Select JT9+JT65 on the Mode menu.

Toggle the Tx mode button to read Tx JT65 #, and set the Tx and Rx frequencies to 1718 Hz.

Double-click on Erase to clear both text windows.

Bins/Pixel = 7

JT65 …​. JT9 = 2500

Adjust the width of the Wide Graph window so that the upper frequency limit is approximately 4000 Hz.

Select File | Open and navigate to ...\save\samples\JT9+JT65\130610_2343.wav. The waterfall should look something like this:

Confirm that mouse-click behavior is similar to that described earlier, in Example 1. WSJT-X automatically determines the mode of each JT9 or JT65 message.

Double-click on the waterfall near 815 Hz: a JT65 message originating from W7VP will be decoded and appear in the Rx Frequency window. Between the UTC and Freq columns on the decoded text line you will find dB, the measured signal-to-noise ratio, and DT, the signal’s time offset in seconds relative to your computer clock.

Double-click on the waterfall at 3196 Hz. The program will decode a JT9 message from IZ0MIT:

Scroll back in the Band Activity window and double-click on the message CQ DL7ACA JO40. The program will set Tx mode to JT65 and the Rx frequency to that of DL7ACA, 975 Hz. If you hold down the Ctrl key, both Rx and Tx frequencies will be moved. If you had checked Double-click on call sets Tx Enable on the Setup menu, the program would configure itself to begin a transmission and start a QSO with DL7ACA.

Hold Ctrl down and double-click on the decoded JT65 message CQ TA4A KM37. The program will set Tx mode to JT9 and the Rx and Tx frequencies to 3567 Hz. The program is now configured properly for a JT9 QSO with TA4A.

Select File | Open and navigate to …​\save\samples\130418_1742.wav.

Select FT8 on the Mode menu.

Set Tx frequency to 1600 Hz, Rx to 1442 Hz.

Double-click on Erase to clear both text windows.

Bins/Pixel = 4, Start = 200 Hz, N Avg = 2

Adjust the width of the Wide Graph window so that the upper frequency limit is approximately 2600 Hz.

Select File | Open and navigate to ...\save\samples\FT8\181201_180245.wav. The waterfall and Band Activity window should look something like the following screen shots. (This recording was made during the "FT8 Roundup" contest, so most transmissions happen to be using RTTY Roundup message formats.)

Click with the mouse anywhere on the waterfall display. The green Rx frequency marker will jump to your selected frequency, and the Rx frequency control on the main window will be updated accordingly.

Do the same thing with the Shift key held down. Now the red Tx frequency marker and its associated control on the main window will follow your frequency selections.

Do the same thing with the Ctrl key held down. Now the both colored markers and both spinner controls will follow your selections.

Double-clicking at any frequency on the waterfall does all the things just described and also invokes the decoder in a small range around the Rx frequency. To decode a particular signal, double-click near the left edge of its waterfall trace.

Now double-click on any of the the lines of decoded text in the Band Activity window. Any line will show the same behavior, setting Rx frequency to that of the selected message and leaving Tx frequency unchanged. To change both Rx and Tx frequencies, hold Ctrl down when double-clicking.

Your callsign and grid locator set to correct values

PTT and CAT control (if used) properly configured and tested

Computer clock properly synchronized to UTC within ±1 s

Audio input and output devices configured for sample rate 48000 Hz, 16 bits

Radio set to USB (upper sideband) mode

Radio filters centered and set to widest available passband (up to 5 kHz).

On the Settings | General tab check Enable VHF/UHF/Microwave features and Single decode.

For EME, check Decode after EME delay to allow for extra path delay on received signals.

If you will use automatic Doppler tracking and your radio accepts frequency-setting commands while transmitting, check Allow Tx frequency changes while transmitting. Transceivers known to permit such changes include the IC-735, IC-756 Pro II, IC-910-H, FT-847, TS-590S, TS-590SG, TS-2000 (with Rev 9 or later firmware upgrade), Flex 1500 and 5000, HPSDR, Anan-10, Anan-100, and KX3. To gain full benefit of Doppler tracking your radio should allow frequency changes under CAT control in 1 Hz steps.

On the Radio tab select Split Operation (use either Rig or Fake It; you may need to experiment with both options to find one that works best with your radio).

On the right side of the main window select Tab 1 to present the traditional format for entering and choosing Tx messages.

If you are using transverters, set appropriate frequency offsets on the Settings | Frequencies tab. Offset is defined as (transceiver dial reading) minus (on-the-air frequency). For example, when using a 144 MHz radio at 10368 MHz, Offset (MHz) = (144 - 10368) = -10224.000. If the band is already in the table, you can edit the offset by double clicking on the offset field itself. Otherwise a new band can be added by right clicking in the table and selecting Insert.

On the View menu, select Astronomical data to display a window with important information for tracking the Moon and performing automatic Doppler control. The right-hand portion of the window becomes visible when you check Doppler tracking.

Select Full Doppler to DX Grid if you know your QSO partner’s locator and he/she will not be using any Doppler control.

Select Own Echo to enable EME Doppler tracking of your receive frequency to your own echo frequency. Your Tx frequency will remain fixed and is set to the Sked frequency. This mode can be used when announcing your CQ call on a specific frequency and listening on your own echo frequency. It can also be used for echo testing with Echo mode.

Select Constant frequency on Moon to correct for your own one-way Doppler shift to or from the Moon. If your QSO partner does the same thing, both stations will have the required Doppler compensation. Moreover, anyone else using this option will hear both of you without the need for manual frequency changes.

Select On Dx Echo when your QSO partner is not using automated Doppler tracking, and announces his/her transmit frequency and listening on their own echo frequency. When clicked, this Doppler method will set your rig frequency on receive to correct for the mutual Doppler shift. On transmit, your rig frequency will be set so that your QSO partner will receive you on the same frequency as their own echo at the start of the QSO. As the QSO proceeds, your QSO partner will receive you on this starting frequency so that they do not have to retune their receiver as the Doppler changes. Sked frequency in this case is set to that announced by your QSO partner.

Select Call DX after tuning the radio manually to find a station, with the Doppler mode initally set to None. You may be tuning the band looking for random stations, or to a frequency where a station has been seen on an SDR display. It is usually necessary to hold down the Ctrl key while tuning the radio. From the moment Call DX is pressed, your transmit frequency is set so that your echo will fall on the same frequency you (and the DX station) are listening.

See Astronomical Data for details on the quantities displayed in this window.

Select JT4 from the Mode menu. The central part of the main window will look something like this:

Select the desired Submode, which determines the spacing of transmitted tones. Wider spacings are used on the higher microwave bands to allow for larger Doppler spreads. For example, submode JT4F is generally used for EME on the 5.7 and 10 GHz bands.

For EME QSOs some operators use short-form JT4 messages consisting of a single tone. To activate automatic generation of these messages, check the box labeled Sh. This also enables the generation of a single tone at 1000Hz by selecting Tx6, to assist in finding signals initially. The box labeled Tx6 toggles the Tx6 message from 1000Hz to 1250Hz to indicate to the other station that you are ready to receive messages.

Select Deep from the Decode menu. You may also choose to Enable averaging over successive transmissions and/or Enable deep search (correlation decoding).

Select MSK144 from the Mode menu.

Select Fast from the Decode menu.

Set the audio receiving frequency to Rx 1500 Hz.

Set frequency tolerance to F Tol 100.

Set the T/R sequence duration to 15 s.

To match decoding depth to your computer’s capability, click Monitor (if it’s not already green) to start a receiving sequence. Observe the percentage figure displayed on the Receiving label in the Status Bar:

The displayed number (here 17%) indicates the fraction of available time being used for execution of the MSK144 real-time decoder. If this number is well below 100% you may increase the decoding depth from Fast to Normal or Deep, and increase F Tol from 100 to 200 Hz.

T/R sequences of 15 seconds or less requires selecting your transmitted messages very quickly. Check Auto Seq to have the computer make the necessary decisions automatically, based on the messages received.

For operation at 144 MHz or above you may find it helpful to use short-format Sh messages for Tx3, Tx4, and Tx5. These messages are 20 ms long, compared with 72 ms for full-length MSK144 messages. Their information content is a 12-bit hash of the two callsigns, rather than the callsigns themselves, plus a 4-bit numerical report, acknowledgment (RRR), or sign-off (73). Only the intended recipient can decode short-messages. They will be displayed with the callsigns enclosed in <> angle brackets, as in the following model QSO

CQ K1ABC FN42
                   K1ABC W9XYZ EN37
W9XYZ K1ABC +02
                   <K1ABC W9XYZ> R+03
<W9XYZ K1ABC> RRR
                   <K1ABC W9XYZ> 73

Select Echo from the Mode menu.

Check Doppler tracking and Constant frequency on the Moon on the Astronomical Data window.

Be sure that your rig control has been set up for Split Operation, using either Rig or Fake It on the Settings | Radio tab.

Click Enable Tx on the main window to start a sequence of 6-second cycles.

WSJT-X calculates and compensates for Doppler shift automatically. As shown in the screen shot below, when proper Doppler corrections have been applied your return echo should always appear at the center of the plot area on the Echo Graph window.

To enable automatic band hopping, check the Band Hopping box on the main window.

Click Schedule to open the WSPR Band Hopping window, and select the bands you wish to use at each time of day.

Band-switching occurs after each 2-minute interval. Preferred bands are identified with time slots in a repeating 20-minute cycle, according to the following table:

If the preferred band is not active according to your band-hopping schedule, a band will be selected at random from among the active bands.

If the box labeled Tune is checked for a particular band, WSJT-X transmits an unmodulated carrier for several seconds just after switching to that band and before the normal Rx or Tx period starts. This feature can be used to activate an automatic antenna tuner (ATU) to tune a multi-band antenna to the newly selected band.

Depending on your station and antenna setup, band changes might require other switching besides retuning your radio. To make this possible in an automated way, whenever WSJT-X executes a successful band-change command to a CAT-controlled radio, it looks for a file named user_hardware.bat, user_hardware.cmd, user_hardware.exe, or user_hardware in the working directory. If one of these is found, WSJT-X tries to execute the command

user_hardware nnn

In the above command nnn is the band-designation wavelength in meters. You must write your own program, script, or batch file to do the necessary switching at your station.

When CQ only is checked, only messages from stations calling CQ will be displayed in the left text panel.

Log QSO raises a dialog window pre-filled with known information about a QSO you have nearly completed. You can edit or add to this information before clicking OK to log the QSO. If you check Prompt me to log QSO on the Settings → Reporting tab, the program will raise the confirmation screen automatically when you send a message containing 73. Start Date and Start Time are set when you click to send the Tx 2 or Tx 3 message, and backed up by one or two sequence lengths, respectively. (Note that the actual start time may have been earlier if repeats of early transmissions were required.) End date and time are set when the Log QSO screen is invoked.

Stop will terminate normal data acquisition in case you want to freeze the waterfall or open and explore a previously recorded audio file.

Monitor toggles normal receive operation on or off. This button is highlighted in green when the WSJT-X is receiving. If you are using CAT control, toggling Monitor OFF relinquishes control of the rig; if Monitor returns to last used frequency is selected on the Settings | General tab, toggling Monitor back ON will return to the original frequency.

Erase clears the right-hand decoded text window. Double-clicking Erase clears both text windows.

Clear Avg is present only in modes that support message averaging. It provides a way to erase the accumulating information, thus preparing to start a new average.

Decode tells the program to repeat the decoding procedure at the Rx frequency (green marker on waterfall scale), using the most recently completed sequence of received data.

Enable Tx toggles automatic T/R sequencing mode on or off and highlights the button in red when ON. A transmission will start at the beginning of the selected (odd or even) sequence, or immediately if appropriate. Toggling the button to OFF during a transmission allows the current transmission to finish.

Halt Tx terminates a transmission immediately and disables automatic T/R sequencing.

Tune toggles the program into Tx mode and generates an unmodulated carrier at the specified Tx frequency (red marker on waterfall scale). This process is useful for adjusting an antenna tuner or tuning an amplifier. The button is highlighted in red while Tune is active. Toggle the button a second time or click Halt Tx to terminate the Tune process. Note that activating Tune interrupts a receive sequence and will prevent decoding during that sequence.

Uncheck the box Menus to make the top-of-window menus disappear, leaving more vertical space for decoded messages.

A drop-down list of frequencies and bands at upper left lets you select the operating band and sets dial frequency to a value taken from the Frequencies tab on the Settings window. If CAT control is active the radio’s dial frequency will be set accordingly; if not, you must tune the radio manually.

Alternatively, you can enter a frequency (in MHz) or band name in recognized ADIF format, for example 630m, 20m, or 70cm. The band-name format works only if a working frequency has been set for that band and mode, in which case the first such match is selected.

You can also enter a frequency increment in kHz above the currently displayed integer MHz. For example, if the displayed frequency is 10,368.100, enter 165k (don’t forget the k!) to QSY to 10,368.165.

A small colored circle appears in green if the CAT control is activated and functional. The green circle contains the character S if the rig is detected to be in Split mode. The circle becomes red if you have requested CAT control but communication with the radio has been lost.

If DX Grid contains a valid Maidenhead locator, the corresponding great-circle azimuth and distance from your location are displayed.

The program can maintain a database of callsigns and locators for future reference. Click Add to insert the present call and locator in the database; click Lookup to retrieve the locator for a previously stored call. This feature is mainly useful for situations in which the number of active stations is modest and reasonably stable, such as EME (Earth-Moon-Earth) communication. The callsign file name is CALL3.TXT.

Check Tx even to transmit in even-numbered UTC minutes or sequences, starting at 0. Uncheck this box to transmit in the odd sequences. The correct selection is made automatically when you double-click on a decoded text line, as described in the Basic Operating Tutorial.

The Tx and Rx audio frequencies can be set automatically by double-clicking on decoded text or a signal in the waterfall. They can also be adjusted using the spinner controls.

You can force Tx frequency to the current Rx frequency by clicking the Tx←Rx button, and vice-versa for Rx←Tx. The on-the-air frequency of your lowest JT9 or JT65 tone is the sum of dial frequency and audio Tx frequency.

Check the box Hold Tx Freq to ensure that the specified Tx frequency is not changed automatically when you double-click on decoded text or a signal in the waterfall.

For modes lacking a multi-decode feature, or when Enable VHF/UHF/Microwave features has been checked on the Settings → General tab, the F Tol control sets a frequency toilerance range over which decoding will be attempted, centered on the Rx frequency.

The Report control lets you change a signal report that has been inserted automatically. Typical reports for the various modes fall in the range –30 to +20 dB. Remember that JT65 reports saturate at an upper limit of -1 dB.

In some circumstances, especially on VHF and higher bands, you can select a supported submode of the active mode by using the Submode control. The Sync control sets a minimum threshold for establishing time and frequency synchronization with a received signal.

Spinner control T/R xx s sets sequence lengths for transmission and reception in ISCAT, MSK144, and the fast JT9 modes.

With Split operation activated on the Settings → Radio tab, in MSK144 and the fast JT9 submodes you can activate the spinner control Tx CQ nnn by checking the box to its right. The program will then generate something like CQ nnn K1ABC FN42 for your CQ message, where nnn is the kHz portion of your current operating frequency, in the range 010 to 999. Your CQ message Tx6 will then be transmitted at the calling frequency selected in the Tx CQ nnn spinner control. All other messages will be transmitted at your current operating frequency. On reception, when you double-click on a message like CQ nnn K1ABC FN42 your rig will QSY to the specified frequency so you can call the station at his specified response frequency.

Checkboxes at bottom center of the main window control special features for particular operating modes:

Select the next message to be transmitted (at the start of your next Tx sequence) by clicking on the circle under Next.

To change to a specified Tx message immediately during a transmission, click on a rectangular button under the Now label. Changing a Tx message in mid-stream will slightly reduce the chance of a correct decode, but it is usually OK if done in the first 10-20% of a transmission.

All six Tx message fields are editable. You can modify an automatically generated message or enter a desired message, keeping in mind the limits on message content. See Protocol Specifications for details.

Click on the pull-down arrow for message #5 to select one of the pre-stored messages entered on the Settings | Tx Macros tab. Pressing Enter on a modified message #5 automatically adds that message to the stored macros.

In some circumstances it may be desirable to make your QSOs as shiort as possible. To configure the program to start contacts with message #2, disable message #1 by double-clicking on its round radio-button or rectangular Tx 1 button. Similarly, to send RR73 rather than RRR for message #4, double-click on one of its buttons.

Clicking a button puts the appropriate message in the Gen Msg box. If you are already transmitting, the Tx message is changed immediately.

You can enter and transmit anything (up to 13 characters, including spaces) in the Free Msg box.

Click on the pull-down arrow in the Free Msg box to select a pre-stored macro. Pressing Enter on a modified message here automatically adds that message to the table of stored macros.

Bins/Pixel controls the displayed frequency resolution. Set this value to 1 for the highest possible resolution, or to higher numbers to compress the spectral display. Normal operation with a convenient window size works well at 2 to 8 bins per pixel.

JT65 nnnn JT9 sets the dividing point (blue marker) for wide-band decoding of JT65 and JT9 signals in JT9+JT65 mode. The decoder looks for JT65 signals everywhere, but JT9 signals only above this frequency. This setting is stored separately for each band.

Start nnn Hz sets the low-frequency starting point of the waterfall frequency scale.

N Avg is the number of successive spectra to be averaged before updating the display. Values around 5 are suitable for normal JT9 and JT65 operation. Adjust N Avg to make the waterfall move faster or slower, as desired.

A dropdown list below the Palette label lets you select from a wide range of waterfall color palettes.

Click Adjust to activate a window that allows you to create a user-defined palette.

Check Flatten if you want WSJT-X to compensate for a sloping or uneven response across the received passband. For this feature to work properly, you should restrict the range of displayed frequencies so that only the active part of the spectrum is shown.

Select Current or Cumulative for the spectrum displayed in the bottom one-third of the Wide Graph window. Current is the average spectrum over the most recent N Avg FFT calculations. Cumulative is the average spectrum since the start of the present UTC minute. Linear Avg is useful in JT4 mode, especially when short-form messages are used.

Four sliders control reference levels and scaling for waterfall colors and the spectrum plot. Values around midscale are usually about right, depending on the input signal level, the chosen palette, and your own preferences. Hover the mouse over a control to display a tip reminding you of its function.

The Spec nn% control may be used to set the fractional height of the spectrum plotted below the waterfall.

Smooth is active only when Linear Average has been selected. Smoothing the displayed spectrum over more than one bin can enhance your ability to detect weak EME signals with Doppler spread more than a few Hz.

Bins/Pixel controls the displayed frequency resolution. Set this value to 1 for the highest possible resolution, or to higher numbers to compress the spectral display.

Gain and Zero sliders control scaling and offset of plotted spectra.

Smooth values greater than 0 apply running averages to the plotted spectra, thereby smoothing the curves over multiple bins.

Label N shows the number of echo pulses averaged.

Click the Colors button to cycle through 6 possible choices of color and line width for the plots.

Switch to FreqCal mode

In the Working Frequencies box on the Settings → Frequencies tab, delete any default frequencies for FreqCal mode that are not relevant for your location. You may want to replace some of them with reliably known frequencies receivable at your location.

In most cases you will want to start by deleting any existing file fmt.all in the directory where your log files are kept.

To cycle automatically through your chosen list of calibration frequencies, check Execute frequency calibration cycle on the Tools menu. WSJT-X will spend 30 seconds at each frequency. Initially no measurement data is saved to the fmt.all file although it is displayed on screen, this allows you to check you current calibration parameters.

During the calibration procedure, the radio’s USB dial frequency is offset 1500 Hz below each FreqCal entry in the default frequencies list. As shown in the screen shot below, detected signal carriers therefore appear at about 1500 Hz in the WSJT-X waterfall.

To start a measurement session check the Measure option and let the calibration cycle run for at least one complete sequence. Note that, while measuring, any existing calibration parameters are automatically disabled so you may have to increase the FTol range if your rig is off freqeuncy by more than a few Hertz in order to capture valid measurements.

Record a number of wav files that contain decodable signals from your chosen reference station. Best results will be obtained when the signal-to-noise ratio of the reference signals is 10 dB or greater.

Enter the callsign of the reference station in the DX Call box.

Select Measure phase response from the Tools menu, and open each of the wav files in turn. The mode character on decoded text lines will change from & to ^ while WSJT-X is measuring the phase response, and it will change back to & after the measurement is completed. The program needs to average a number of high-SNR frames to accurately estimate the phase, so it may be necessary to process several wav files. The measurement can be aborted at any time by selecting Measure phase response again to toggle the phase measurement off.

Select Equalization tools …​ under the Tools menu and click the Phase …​ button to view the contents of the Log directory. Select the desired pcoeff file. The measured phase values will be plotted as filled circles along with a fitted red curve labeled "Proposed". This is the proposed phase equalization curve. It’s a good idea to repeat the phase measurement several times, using different wav files for each measurement, to ensure that your measurements are repeatable.

Once you are satisfied with a fitted curve, push the Apply button to save the proposed response. The red curve will be replaced with a light green curve labeled "Current" to indicate that the phase equalization curve is now being applied to the received data. Another curve labeled "Group Delay" will appear. The "Group Delay" curve shows the group delay variation across the passband, in ms. Click the Discard Measured button to remove the captured data from the plot, leaving only the applied phase equalization curve and corresponding group delay curve.

To revert to no phase equalization, push the Restore Defaults button followed by the Apply button.

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