FT8 Thoughts and Developments
Mike Richards G4WNC reports on the latest developments to the popular FT8 software.
Mike Richards G4WNC reports on the latest developments to the popular FT8 software.
The introduction of FT8 has completely transformed HF data modes operating and activity more than any other system I can think of. The PSK Reporter (pskreporter.info) site is a good indicator of mode usage and has a table that shows the utilisation of data modes over the previous two hours. On most occasions when I’ve checked this, FT8 can be seen to be handling around 98% of data modes traffic! Table 1 shows the utilisation of the top six data modes for a two-hour period on September 11th. This shows that FT8 is dominating data modes on the HF bands with CW in second place.
I think there are several reasons for the mode’s amazing success. The most obvious reason is that FT8 is a foolproof communication system that works extremely well. Joe Taylor K1JT’s development team includes some of the best brains in amateur radio communications and we get to enjoy the benefits through the WSJT-X suite of programs. Many have criticised FT8 because it stifles content and permits little more than the bare minimum to confirm a contact. However, if you look back at PSK31, RTTY and even CW, you will see that the desire for minimal (rubber-stamp) contacts has been with us for a very long time. It is therefore unfair to lay the blame on FT8 because it’s simply fulfilling a demand. One of the other reasons for the mode’s success is today’s propagation conditions. Not only are we in the sunspot doldrums but we have an ever-increasing RF noise floor, thanks to the rapid spread of electronics and connected devices in the domestic environment. This is compounded by the cheap imported electronic products that flaunt the EMC regulations and the telecom operators that seem to be exempt from the rules when it suits them (Power Line Technology, PLT). The net result is very difficult operating conditions for many amateurs, particularly those living in our towns and cities. For those amateurs, FT8 has transformed the bands because they can continue to make contacts under these very poor conditions.
All WSJT-X modes enjoy continuous development because Joe Taylor’s team are always looking for improvements. The next release to get to us will be WSJT-X v2.0 and a Beta test version was expected to be launched in September or October this year. Keep an eye on the WSJT-X home page (below) for more news on the release dates.
Version 2.0 brings some significant changes for both FT8 and MSK144. In addition to improving the installation and upgrade process, v2.0 will bring support for many of the major contest message formats. To make room for the additional content, the FT8 information payload is being increased to 77 bits. The DXpedition mode is also undergoing improvement. A particularly welcome feature of v2.0 is its ability to use the contest and DXpedition modes seamlessly and automatically without using tick boxes. One interesting addition is the provision of a 71-bit telemetry message that can be used to send arbitrary information. Maybe this could be used to add some personalised messages to the FT8 QSOs.
As you may have guessed from the changes I’ve described, FT8 v2.0 will not be compatible with the existing FT8 system. As a result, the update to v2.0 is a mandatory requirement, once the testing period has finished. This shouldn’t be an onerous task because one of the objectives of v2.0 is to simplify the update process. At the moment, the plan is to include dual working in the beta version of v2.0 so it can be used with the v1.9 software.
FT8Call is a new and rapidly developing, experimental, offshoot of FT8 that is examining the feasibility of a keyboard-to-keyboard mode by adding a messaging and network protocol layer on top of the robust FT8 mode. This new mode is neither endorsed nor supported by the main WSJT-X development team but is based on their WSJT-X GPLv3 Licensed code and is heavily influenced by both FLDIGI and FSQCall.
FT8Call uses two main message types, which are soundings and directed messages. Soundings are typically used as beacons to announce to all that your station is active and available, whereas directed messages provide a way to direct communications to a specific station. Within the directed messages there are several sub-modes that include command requests, acknowledgements, free text and free text relays, but more on this later. Channel allocation, Fig. 1, uses 1500Hz as the centre frequency with each channel occupying a 50Hz bandwidth and spaced 10Hz apart. This allows for up to 25 channels in a 1500Hz wide band centred on 1500Hz. If you’d like to know more about the inner working of FT8Call, there is a useful design document available for download on GitHub at:
From a protocol viewpoint, two important changes have been made. The first is to modify the CRC (Cyclic Redundancy Check) so that FT8 and FT8Call signals don’t get confused and the second is to allow the full 75-bit payload to be used to transport data.
The first step is to get a copy of FT8Call and this is available for free download from:
Downloads are available for Windows 7-10, Mac OS 10.11, Linux and Raspberry Pi. The Linux downloads are slightly unusual in that they are available in AppImage format. This is a very useful format that has the FT8Call software and all its dependencies wrapped up in a single package. To install the AppImage, you download the file to a directory of your choice and make it executable – that’s it! FT8Call is also available in AppImage format for the Raspberry Pi, so installation is as simple as it gets. For those that are interested, I’ve now added FT8Call to my Data Modes microSD cards for the Raspberry Pi, see my website:
The Windows download is a standalone EXE installer that you can run from the download folder in Windows. Setting up FT8Call is pretty much the same as WSJT-X, but I’ve shown the step-by-step process here:
- Use the File – Settings menu and the General tab to enter your callsign, locator and station details, Fig. 2.
- Move to the Radio tab and enter your radio details, if you’re using CAT. If you’d rather use VOX, that’s fine, and you should leave the radio set to None.
- The next step is to use the Audio tab to select the appropriate soundcard.
- Finally, I recommend enabling spotting in the Reporting tab. When using a new mode such as FT8Call, it’s helpful to advertise your presence and report your spots to help new users find each other, Fig. 3.
During the download, you may have noticed that FT8Call has a time-limited licence. This has been done to force operators to use the latest software version. This is particularly important for a new mode such as FT8Call because the software is frequently updated to remove bugs or add new features.
In my experience with FT8Call, 20m is the most active band during the day with 40m being the best bet for evenings. As with most amateur modes, the weekends are the busiest. To help you get started, I’ve shown a screen capture of the main screen, Fig. 4. As you can see, the screen is divided into four text panels. The left-hand panel shows band activity across all channels, while the right-hand side shows calling stations and when they were last seen. The central section relates to your station with the top part displaying all the incoming and outgoing directed messages. The bottom section is your type-ahead buffer where you enter transmit commands and messages. Looking at the top right of the main screen, you will see a set of control buttons and you should make note of the Auto and BCN buttons because these activate the automated features of FT8Call. Auto activates the transmission of automatic responses from your station such as SNR, heard list and so on. The BCN button activates the beacon that transmits your callsign and locator at regular intervals with a default interval of 30 minutes.
The beacon is a useful feature in a new mode because it lets other operators see that you are on frequency. The beacon uses the current tuned frequency, unless it’s busy whereupon it will select a random free channel. In the current version, the beacon cannot detect if you’re in a QSO, so can transmit on top of your QSO. I suspect this will be fixed in a later version but the simple fix is to disable the beacon when you start a QSO. Please note that the beacon and Auto modes should only be used while you’re in control of your station; they are not for unattended operation.
Starting to Operate
Before you start operating, I suggest you spend time monitoring the bands so you can see how FT8Call is being used. This is particularly important with a new mode because operating methods often change as the mode develops. I also recommend that you get a copy of the FT8Call pre-release documentation. This is available from:
You will also find a set of operational guides on the FT8Call site here:
One particularly interesting feature of FT8Call is the directed calls that can be used to solicit a response from other stations. For example, ALLCALL? will trigger all stations that can hear you and have Auto enabled to send your SNR (Signal-to-Noise Ratio). This is particularly useful for discovering stations that are within range, so you can follow up with a directed QSO. To start a QSO with a specific station, begin with the callsign of the station you want to contact, followed by the message, such as “G4LFM How copy?” You don’t need to add your own callsign because this is automatically added by FT8Call, so the actual transmitted message becomes: G4WNC: G4LFM How copy? If you carry out all your QSOs in plain language using FT8Call, they can take a while to get through so it is common practice to use CW abbreviations to help shorten the message. One other important point to note is the end of message symbol ⌁. Because messages can span several 15 second frames, FT8Call uses the lightning symbol (⌁) to mark the end of a message.
That’s all I’ve got space for this time so next time I’ll show you how to use some of the more advanced features of FT8Call. If you want to keep up to date with FT8Call developments, I recommend joining that mailing list at:
Table 1: PSKreporter (pskreporter.info) two-hour analysis, September 12th 0918UTC
Data Mode Number of active stations Percentage
FT8 311895 98.91%
CW 1568 0.50%
SIM31 787 0.25%
FT8Call 674 0.21%
PSK31 215 0.07%
JT65 208 0.07%
This article was featured in the December 2018 issue of Practical Wireless