A new HF digital mode - FT8

After my last trip, I caught the dreaded airplane flu and have not had the desire to do much but watch tv (which I hate) or go play with my radio.

A few days ago I decided that I did not want to ragchew, so I spun up WSJT-X and tuned 14.076. 

I saw a bunch of weird blocks of data every 15 seconds at the low end of the band? There was enough of it that it was screwing up my AGC and making it hard to do JT65.  

Intrigued, I made a screen copy of my flexradio and posted it on a couple of ham forums. The response was that it was the new mode FT8.

In a nutshell FT8 is a mode similar JT65, and JT9. The operation is very similar, but much more fast paced. With JT65 and JT9 the transmission is about 55 seconds long with 5 seconds for processing and operator control. FT8 is based on a 15 second interval with about 1 second for processing and operator control.

This means that you really need to automate your station or you will not have much fun with this new mode. The purists out there will say that this is not ham radio since it is computer controlled, and the operator does not do anything other than clicking. I am sure the guys who said that considers the use of anything but a straight key is not true ham radio since something is automated. Like all of the newer modes, this mode requires not only ham radio skills in the setup of a station, antennas, grounding, etc. It requires information technology skills.

If you want to have fun with FT8, I will suggest the following setup. This setup also works for all of the other modes that WSJT-X works with.

1. Download and install WSJT-X v1.8.0-rc1.

2. Figure out your maidenhead location. It is a mandatory requirement for operating these modes.

3. Go to Settings and go from here.

  •  Settings - General Tab
    • Make sure your call and location is correct.
    • Click Display distance in miles
    • Click Tx Messages to Rx Frequency
    • Click Double-Click on call sets Tx enable
    • Disable Tx after Sending 73
    • Set the TX watchdog to 10 minutes
  • Radio Tab
    • Select your rig and configure it.  I use a Flex6300 and the Paid Version of HRD
    • Test CAT and verify that the program is working. Your radio frequency should be on the display.
    • Test PTT - It should work.
  • Audio Tab
    • Make sure that the Input: matches the radios RX or output
    • Make sure that Output: matches the radios TX or input.
  • Reporting Tab
    • Click Logging
    • Click enable PSK Reporter Spotting
    • Enable UDP Server - IP, port 2237
    • Click on all UDP server options, this is critical for a later step.
  • Frequency Calibration
    • Do not mess with this unless you are having problems. Contact me directly and I will help you out.  My info on QRZ is up to date ( KB0FHF )
  • Advanced
    • Under JT65 - enable two-pass decoding

Now turn on your radio.

On the main window MODE, select FT8.

4. Operation Window Setup

  • In the MODE menu select FT8
  • The main window should display the frequency of the radio.
  • Use the pull down and select 20m.
  • The program and radio should be on 14.074 000
  • Lock TX=RX is enabled
  • Auto Seq is Enabled
  • Call 1st is enabled
  • Click tab 2 to use the canned response sequence. 
  • Power - I leave mine set at 100% and control the power on the radio.

5. Radio Setup

  • Drop your power to something below 30 watts. Go as low as you want. I usually run 30 watts.
  • Make sure the radio is always in USB, this applies to all bands.
  • Use the widest filter you have. I run a 4.0K on my flex.
  • Disable AGC and adjust it to a level that does not overload the radio.
  • Disable all DSP functions.
  • Disable TNF if you have that capability.

6. Make sure that your computer time is synced with an external time server. Even being off by a few 100ms will make FT8 unusable. Contact me directly and I can help you with this.

7. TX setup

  • Tune the radio via auto tuner or external tuner and triple check that you have the TX power set below 30 watts.
  • Turn off all TX processing. If you can't, make sure it is set to Normal and not the DX setting.
  • While on the empty frequency ( you did change to an empty frequency for tuning :) ) press the Tune button in the APP. This will send a carrier at the power your radio is set at. On the radio or via the PWR slide on the app, adjust the power to where you are not splattering all over the place. On a flex, Adjust until the Level is just below the yellow line and is still green.
  • Enable the Monitoring - MON on a flex and adjust the volume.

8. The program should be showing lots of QSOs at this point. Feel free to double click on one of the CQs. The actual QSO is automated, and you will be promted to save the log at the 73 portion of the QSO.

9. When ready locate an empty spot on the waterfall and select it. Click the Enable Tx button and wait until the end of a cycle and press CQ.  Sit back and let it go.

Now you make have noticed that the logs are separate from your favorite logging program and everything is so fast paced that it is hard to check your log book to see if you have worked this station.

Remember earlier when I said to enable the UDP server options?  Download and install JTAlertX v2.10.0, sound files, and call database.  Install in that order.

Shutdown WSJT-X.

Set up JTAlertX. The complicated part of this process is getting it to work with your specific logbook.

1. Settings

  • Own Call
    • Enable Own Call Alert
    • Put the call sign that you use in #1
    • Test the audio by pressing Test, you should hear some dings.
  • Enable CQ and QRZ Alerts
  • Enable Worked B4 - Once you have your logbook running, this helps prevent you from hitting the same person all of the time.
  • Logging
    • Pick your database and set it up accordingly.
    • I use HRD Ver 5 - THe program should pull the database info in.

2. Shut down WSJT and JTAlertX

3. Start JTAlertX and then start WSJT-X

4. If everything is working, you should hear CQ and see that JTAlertX has the information about the current cycle. Click a CQ and sit back. 

5. Once the QSO is at the 73 stage, you will be prompted to log. If the logbook is working, then JTAlertX will confirm the log entry. At a later time, check your logbook program.

6. In just a little bit, you should start to see stations that you have worked as with either a B4 after the call and it should be greyed out a little bit. 

This is much more that this program will do, but this is the starting point.

If you need any help, just ask me.

73 de KB0FHF aka The Technical Skeptic