Last Updated on April 16, 2021
The FT8 digital mode is the latest in a series of weak signal applications for amateur radio. When FT8, jointly developed by Joe Taylor and Steve Franke (K9AN), was announced it was described as being designed for, “multi-hop Es where signals may be weak and fading, openings may be short, and you want fast completion of reliable, confirmable QSO’s.”
So what makes FT8 your next mode?
So, will FT8 kill ham radio as some have posed? True, it is mostly automated. True, it reduces the skill required to make DX contacts. True, it removes conversation from the QSO the same as is true of most DX chasing contacts on any mode. True, it removes some of the human factor. But does that make it bad for amateur radio’s future? Source: FlexRadio
The FT8 digital mode is the latest in a series of weak signal applications for amateur radio. FT8 is designed for fast, reliable and confirmable automated QSOs where callsign, grid square and signal strength are exchanged. JS8 is the same technology, but allows a non automated QSO. The are two separate programs that look very similar.
FT8 Digital Amateur Radio is really gaining momentum right now. With the sun dormant and voice communications at an all time low, FT8 is a digital mode that is exploding in popularity world wide. On this page I’ll share some of my experiences along with tips and tricks to get you going. It’s a fun way to get some use out of the HF bands.
To get going with FT8 Digital Amateur Radio you’ll need a couple of things.
Each radio will be different in the way it’s set up as you’ll hopefully be able to utilise facilities in the setup menus that you wern’t previously aware of. I own an Icom IC-9100 and this was certainly the case for me. The IC-9100 is a radio which allows computer control. It talks to the PC via USB and passes contol of the rig up and back to the PC, as well as audio. This makes setting FT8 up very simple.
All you need is ONE USB cable between the radio and the computer. Follow the manufacturers instructions for setting up your radio, and make sure it works before installing FT8 software.
A resonably powerful computer with good RF shielding is best for this mode. Also, use short, quality USB cables (or audio cables) to minimise RF issues. I’d be using some ferrite rings in the cables if you have a few in the junkbox. The hard work will be done in your soundcard if you don’t have the ability to use USB audio. Laptop or desktop, the choice is what works in the shack or portable.
There are at least 2 programs for FT8 that I’m aware of at the time of writing. There’s WSJT-X available from Princeton University, and there’s JTDX. Both work well, so check out which has the features that works for you. Logging, comms abilities etc. I us WSJT-X as it meets my needs. The both look and behave in a very similar fashion.
Downloads: WSJTX from the Princeton Uni site or JTDX and or JS8Call.
Here’s how I’ve set the IC-9100 to work reliably with FT8. Levels are key. You don’t want to overmodulate or have any distortion in the system.
The key to success is getting a bunch of settings inside the radio to match a bunch of settings in your digital mode software. Begin by getting your IC-9100 menu settings set properly:
The IC-9100 has a DIGITAL MODE. Did you know? I didn’t. When you’re in this digital mode, a small ‘D’ will appear in the top left corner of the display. You’ll see it in the rig photo above.
To turn on Digital Mode on the IC-9000 press and hold the SSB button for a second. The radio will then show the ‘D’ in the corner and the digital filtering will kick in. Now here’s the trick. In the radio tab in WSJT-X software, make sure the Data/PKT option is checked, this way the software will force the radio to stay in this mode. If you have USB selected, the radio will jump out of digital mode every transmission.
A common misconception is somehow becoming convinced that you need to use “USB” (as in Upper Side Band) as the RX/TX mode. That’s correct for a microphone, but very bad practice for digital modes. You want to use “D-USB” or Digital Mode (as in Digital Upper Side Band). This will ensure that the compressor is turned off, along with the RX and TX tone adjustments that would wreck havoc with your signal quality.
Menu of 56 adjusts the USB MOD Level. 25% is going to be close, but your particular radio might need some adjusting. The way you figure that out is to get the radio into transmit mode (perhaps using the “TUNE” button in WSJT-X) and adjusting the USB MOD Level until there is ZERO ALC on your meter. If you are showing ALC action, then your transmit audio is going to be distorted. It is a VERY sensitive adjustment. The general ALC consensus is that a little bit of ALC isn’t a bad thing.
One of the best spin-offs of FT8 digital radio is the global moitoring of signals and propogation. Sites like PskReporter now make it so easy to see if bands are open, and more importantly, how well you’re getting out and where you can be heard. Here you can see pins on a resizeable map, which when filtered correctly, will show you how long ago you were heard. If you know of others, let me know.
Every aspect of our hobby has a Facebook group these days and FT8 is no different. Why not check it out and join.
There are cetain contols in the Windows platform (I’m usinging Windows 10) and the radio that need to be set to work correctly with the software. First thing you need to do is choose and install your software. I went with WSJT-X
Assuming successful software installation, you need to get the USB connected to the radio and make sure you can control the radio from the PC. To test this, from the main screen of WSJT-X, click file -> settings. Then the radio tab. Make sure you’ve selected your radio in the drop down, the PTT method is set to CAT, and the Test CAT button turns green after you click it. If you’re GREEN to go, click the TEST PTT once to test TX and again to stop.
Finally, click OK to go back to the main page of the application and try and change band from the drop down menu just above the reciving audio meter. If the band changes, your data connection is good to go. Now the audio.
You may have noticed that my seetings show the rig control to be Ham Radio Deluxe. The WSJT-X software lets you use other programs you may have on your computer to control your radio. You’ll have to have them running in background for your rig to talk to your compter. See the setup docs that came with the WSJT-X distribution package for more. Below is a direct connection.
No doubt this is the trickiest part of the set up – and this is purely audio levels. Jump back into settings and this time click the audio tab and patch your radio into and out of your soundcard.
The USB audio should appear as a USB Audio Codec. If it doesn’t you’ll need to head into the Widows Sound settings and make sure it’s ENABLED. Mine was disabled for some reason. Press the Windows key on your keyboard, and type ‘sound’. The sound control panel should be highlited. Select this and follow your nose. You should see at least two tabs – Recording and Playback. Right click in this window and make sure ‘Show disabled devices’ is checked. If you’re not sure, a quick Google search will help.
The bar graph audio level meter in WSJT-X should normally read about 30 dB on a ‘dead’ band, increasing to about 50 dB on an active band with about a dozen stations QRV simultaneously, higher still on an HF band buzzing with life and lots of strong FT8 signals. If the level goes too high and turns red, you are reaching the compression point in your sound card and may be over-driving it, causing distortion and sampling errors in the ADC (Analogue to Digital Converter) that, in turn, reduce the ability to decode FT8 signals.
Chapter 5 on page 9 in the user manual will explain all.
Timing is everything when it comes to FT8. Make sure your PC clock is ACCURATE. Visit time.is to make sure.
Your rig will transmit for exactly 15 seconds starting at 00 or 30 seconds (even) or 15 or 45 seconds (odd). If it doesn’t TX or RX at the right time, you’ll overlap the TX/RX window and the result is annoying to stations close by, and you’ll probably miss out on contacts.
A clue to time…. Listen to the cocophany of transmissions on the FT8 frequency. They’ll be right. Look at the waterfall on WSJT-X. If they overlap the green horizontal 15 second line, then CHECK your PC time.
Once you’ve got WSJT-X up and running, there’s a great companion app called GridTracker. It listens to WSJT-X and displays our current contact and band conditions on a map.
Features:
Below is a video by the author which will also give you an idea of what it can do.
And here’s how I run it on my desktop. It’s a suggstion only.
