How to use
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For those familiar with WSJT-X, the use of SlowJT9 should be pretty selfexplaining. But keep in mind that the funcionality is not completely identical to WSJT-X.

After launching SlowJT9 for the first time a "Failed to read settings" warning will appears as the settings file is not yet existing. Before you can use the application for transmitting you have to enter some information. Therefore click on settings:

Station:
In order to enable transmitting it is obligatory to enter a valid call and a 4 or 6 digit WW locator (eg. JO20 or J020IX). For PSKReporter spotting a 6 digit locator is required. If the entries are valid the background colour will change from red to cream.
Optional the difference between the computer clock and UTC can be set.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
Radio:
The transmit/receive switchting can be done by VOX or PPT via the RTS or DTR pin of a serial port. The default setting is VOX. If RTS or DTR is choosen you must select a serial port.
Optional a TX delay (not effective if VOX is choosen) and/or watchdog timer(1) (up to 99 minutes, 0 = no watchdog timer) can be set.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
 
Note that for PTT switching via a serial port in most cases an interface between the computer serial port output and the transmitter PTT input is required.
Audio:
Select the correct input (receive) and output (transmit) channel of the soundcard. In general these should be the same as used for WSJT-X.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
Mode:
Select the mode you want tu use:
  • JT9-1 is the original 1 minute cycle JT9 mode, as used in WSJT-X.
  • JT9-2 is the 2 minute cycle JT9 mode.
  • JT9-5 is the 5 minute cycle JT9 mode.
  • JT9-10 is the 10 minute cycle JT9 mode.

Properties:
  • Tone spacing: in case the exciter signal is divide the tone spacing must be multiplied by the divider ratio in order to get the correct tone spacing for the transmitted signal. Any value between 1 (default, no multiplication) and 9999 can be set.
  • Enable TX after selecting DX call or message: allow automatic reply (transmission) after clicking on a DX call or message.
  • Show TX messages in RX frequency window: your own transmission will be shown in the RX frequency window with a yellow background.
  • Discard the default audio frequency limits(1) on TX: the TX boundaries will be 100 - 4980 Hz regardless of the JT9 submode.
  • Discard the default audio frequency limits(1) on RX: discard the RX boundaries. The lower boundary will be 100 Hz, the upper boundary however will still be limited by the resampling process, being 4980 Hz for JT9-1, 2240 Hz for JT9-2, 840 Hz for JT9-5 and 415 Hz for JT9-10.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
Save:
Select what you want to save.
  • The incoming audio files (WAV format) for later use. The WAV files will be stored in the folder "save". Be aware that this will fill your harddisk at a rate of ± 1.5MB per minute.
  • Decoded messages. All decoded messages will be saved in the file "decoded.txt" than can be found in the folder "extra".
  • Debug information. An number of program steps will be recorded in the file "debug.txt" than can be found in the folder "extra". Saving debug information can be useful to trace errors (bugs) that occur. If you want to report a bug I strongly recommend to run SlowJT9 with "Save debug information" activated, and include (a part of debug.txt) in your bug report.
Be aware that no files will be automaticaly deleted. The files "decoded.txt" and "debug.txt" should not be edited nor deleted while SlowJT9 is running.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
PSK Reporter:
Spotting of the received signal to PSKReporter.info(4) can be enabled / disabled.
If you want to spot to PSR Reporter as listener only (SWL) an ID must be entered.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
Alert:
Spotting of the received signal to PSKReporter.info(4) can be enabled / disabled.
If you want to spot to PSR Reporter as listener only (SWL) an ID must be entered.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.
Front end mixer:
Spotting of the received signal to PSKReporter.info(4) can be enabled / disabled.
If you want to spot to PSR Reporter as listener only (SWL) an ID must be entered.
Confirm the settings by clicking on OK or leave without changes by clicking on Cancel.

 

After setting all required parameters you are ready to use SlowJT9.

 

 

  1. Open this help file.
  2. View the "must read" message. Please read and understand this message before using SlowJT9.
  3. Open the settings, see above.
  4. Open the spectrum window, see further.
  5. Band activity window. All messages received within the audio bandwidth(1) are displayed here. CQ messages have a green background, messages that contain your call have a red background.
  6. Tune : click to tune / stop tuning (toggle function).
  7. Halt TX : click to stop the transmission instantly ("emergency stop").
  8. Enable TX : click to enable / disable transmitting (toggle function).
  9. Erase : click to erase alle messages in the RX frequency window, double-click to erase all messages in the band activity window.
  10. Check this box if you want to transmit the first cycle(2), uncheck to transmit the second cycle(2).
  11. DX call field. Enter the DX call here, either by typing or double-clicking in the band activity window or RX frequency window. The background is red if the DX call is missing or invalid and will turn to cream for a valid call.
  12. Check this box if you only want to change your RX frequency if you click on a call in the band activity or RX frequency windows. If unchecked both RX and TX frequency will change.
  13. Date and time display. Make sure that time is set to UTC, either by setting the computer clock or bu setting the UTC difference in the settings (see above).
  14. Audio input level bar.
  15. Dial frequency, enter the frequency in Hz en press [enter]. Required only if you want to spot to PSKReporter.info(4). Changes will become effective only after pressing [enter] or 5 seconds of no keyboard activity! The background is red for an invalid input, green for a valid input and cream is the input is effective.
  16. Audio input level display. The background is red in case of overload and orange if the level is too low.
  17. Mode display (JT9-1, JT9-2, JT9-5 or JT9-10).
  18. Cycle progress bar. The colour is red for TX, green for RX and yellow if idle. In addition the current status, and in TX the current transmitted message, is displayed.
  19. TX audio frequency field. The frequency must be within the allowed audio range(1). The frequency can be changed by typing or using the up/down arrows. Changes will become effective only after pressing [enter] or 5 seconds of no keyboard activity! The background is red for an invalid input, green for a valid input and cream is the input is effective. Unless the "hold TX frequency" box is checked the frequency will also be changed by double-clicking on a message in the band activity or RX frequency window.
  20. RX audio frequency field. The frequency must be within the allowed audio range(1). The frequency can be changed by typing or using the up/down arrows. Changes will become effective only after pressing [enter] or 5 seconds of no keyboard activity! The background is red for an invalid input, green for a valid input and cream is the input is effective. The frequency will also be changed by double-clicking on a message in the band activity or RX frequency window.
  21. Check this box if you want to ommit the exchange of the WW locator if responding to a CQ call. Instead you will immediately send the report.
  22. Report field. The report must be in the range of -50 to +49 dB. The report can be set or changed by typing or using the up/down arrows. The report will also be changed by double-clicking on a message in the band activity or RX frequency window. The background is red if the report is missing or invalid and will turn to cream for a valid report.
  23. Watchdog timer(2) countdown display, only active if the watchdog timer is enabled. The watchdog timer can be reset by clicking on this display.
  24. RX ← TX : click to set the RX frequency equal to the TX frequency.
  25. TX ← RX : click to set the TX frequency equal to the RX frequency.
  26. Free message field. You can enter up to 13 characters. Allowed charachers are 0..9 A..Z space - @ # < > ? . / +. Double-click to clear this field.
  27. Structured message field. Messages are generated by clicking on one of the CQ Grid dB R+dB RRR 73 buttons or on a message in the band activity or RX frequency window. You cannot type in this field.
  28. Check this box to transmit the structured message.
  29. Check this box to transmit the free message.
  30. Structured message buttons. Click on one of there buttons to generate a structured message. Structured messages can only be generated if the required information (DX call and/or report) is available.
  31. Audio output level slider. Use it to adjust the audio ouput level.
  32. Current cycle(3) display. While for JT9(-1) it is very straighforward to know the current cycle (even minute = 1st cycle, odd minute = 2nd cycle), this is not so for JT9-2 and JT9-5. So for your convenience the current cycle is displayed.
  33. RX frequency window. All messages received on (or very close to) the RX frequency are displayed here. CQ messages have a green background, messages that contain your call have a red background.
  34. Cycle length of received message: 1 = JT9(-1), 2 = JT9-2, 5 = JT9-5, X = JT9-10.
  35. Close SlowJT9.

Spectrum window:

 

 

  1. Close the spectrum view window.
  2. Lower frequency limit adjustment (100 - 4900 Hz in 100 Hz steps).
  3. Upper frequency limit adjustment (200 - 5000 Hz in 100 Hz steps).
  4. TX frequency marker. Any frequency limits will be shown as a gray bar.
  5. RX frequency marker. Any frequency limits will be shown as a gray bar.
  6. Frequency axis (in Hz).
  7. Gain / offset slider.
  8. Waterfall display. Click on the waterfall display to set the RX frequency, double-click to set the TX and RX frequency.
  9. If "Gain" is selected (green background) the slider will adjust the gain. Click to select.
  10. If "Offs" is selected (green background) the slider will adjust the offset. Click to select.
  11. If "AGC" is selected (green background) the gain will be automaticaly adjusted. Click to enable / disable (toggle function).
  12. Signal level to colour conversion column. Can be adjusted by changing the visual gain and noise reference level.
  13. "Black level" offset. Any signal below this level will be black on the the spectrum display.
  14. Spectrum display. Click on the spectrum display to set the "black level" offset.

 

(1): The default audio bandwidth is 200 - 1400 Hz for JT9-1 and JT9-2, 200 - 843 Hz for JT9-5, 200 - 416 Hz for JT9-10. This limitations can be discarded (Settings → Mode).

(2): The cycle duration is 1 minute for JT9(-1), 2 minutes for JT9-2, 5 minutes for JT9-5 and 10 minutes for JT9-10. The first cycle starts at the full hour and from then on first and second cycles follow each other alternately:

  • JT9-1:
    • 12:00-12:01 = 1st cycle
    • 12:01-12:02 = 2nd cycle
    • 12:02-12:03 = 1st cycle
    • 12:03-12:04 = 2nd cycle
    • ...
    • 12:56-12:57 = 1st cycle
    • 12:57-12:58 = 2nd cycle
    • 12:58-12:59 = 1st cycle
    • 12:59-13:00 = 2nd cycle
  • JT9-2:
    • 12:00-12:02 = 1st cycle
    • 12:02-12:04 = 2nd cycle
    • 12:04-12:06 = 1st cycle
    • 12:06-12:08 = 2nd cycle
    • ...
    • 12:52-12:54 = 1st cycle
    • 12:54-12:56 = 2nd cycle
    • 12:56-12:58 = 1st cycle
    • 12:58-13:00 = 2nd cycle
  • JT9-5:
    • 12:00-12:05 = 1st cycle
    • 12:05-12:10 = 2nd cycle
    • 12:10-12:15 = 1st cycle
    • 12:15-12:20 = 2nd cycle
    • ...
    • 12:40-12:45 = 1st cycle
    • 12:45-12:50 = 2nd cycle
    • 12:50-12:55 = 1st cycle
    • 12:55-13:00 = 2nd cycle
  • JT9-10:
    • 12:00-12:10 = 1st cycle
    • 12:10-12:20 = 2nd cycle
    • 12:20-12:30 = 1st cycle
    • 12:30-12:40 = 2nd cycle
    • 12:40-12:50 = 1st cycle
    • 12:50-13:00 = 2nd cycle

(3): The watchdog timer, if active, will stop transmission when it trips. The time can be set between 0 (not active) and 99 minutes. The watchdog times can be reset by clicking on the watchdog timer countdown display. It is also reset by initiating a generated message.

(4): In order to send spots to PSKReporter.info

Only captured messages with a valid callsign and WW-locator (4 or 6 digits) will be uploaded to PSKReporter.info.
Important: JT9-2, JT9-5 and JT9-10 spots can only be seen at PSKReporter.info if "JT" or "all modes" is selected. If "JT9" is selected only JT9-1 spots will be shown.