FT 8, WSPR AND THE SHORTWAVE LISTENER

An eQSL received from Vlad UA6027SWL confirming my FT8 QSO with CT1AGS.
Clearly, Vlad is a FIFA World Cup fan!

FT8, WSPR and the Shortwave Listener

(This post is an article I wrote for "The World of Shortwave Listening" column of The Spectrum Monitor magazine - August 2018 issue. Further details on this excellent publication are available at www.thespectrummonitor.com)

Well, it’s finally happened! It had to…eventually! I have been dragged kicking and screaming into the twenty-first century. I’ve joined the massive crowd of radio operators revelling in the joys of the new digital mode - FT8. And I love it!

I have been on FT8 and WSPR modes nearly every day for the past three months making contacts around the world using low power, anywhere from 2 to 25 watts output. Being located in the lower southeastern part of Australia, well away from the highly concentrated ham populations of Europe, North America and Asia, has probably meant that my QSO rate is well down compared to many TSM readers in the northern hemisphere. So, on some occasions, it has been a hard slog trying to break through and make contacts with stations north of the equator. On the other hand, my location allows me to operate without the severe QRM and splatter that can occur for numerous amateur radio operators living in highly populated parts of the world, all within close proximity to each other.

Prior to my recent fascination with FT8 and WSPR, I am embarrassed to say that my only experience with digital modes was some years back with PSK 31. And that interest only lasted about five minutes! Indeed, much of my transmitting activities on the ham bands have been quite muted for over a decade now. Back in the 80s and 90s, I was very active, chasing DX on SSB with the standard three element tri-band yagi, entering occasional local or international contests, and working portable/mobile with some success. But over the last 15 years, much of my time on the HF spectrum has been spent listening, monitoring the shortwave broadcasters - both domestic and international. “Going back to my roots” I called it, back to where my interest in radio all started in the late 60s and throughout the 70s.

But the thing that has drawn me out of temporary “retirement” from transmitting activities has been the idea that you can use a digital mode to get a message across the globe with relatively low power. FT8, WSPR and other modes such as JT65 and JT9 appear to be rather robust protocols, offering you the facilities to make weak signal QSOs despite weird propagation and fading characteristics, heavy interference from adjacent stations, and even in extremely noisy local manmade RF environments, using just a tiny part of the HF spectrum in each of the designated amateur bands. It is really quite impressive!

So why am I writing about these fancy digital modes in a shortwave listening column? Stick with me, my friend!

So, what is this FT8 mode?

FT8 burst onto the ham radio digital communications scene during the second half of 2017. In the twelve months since it has been adopted by amateur radio operators across the globe as the most popular digital mode currently in use. Indeed, some of the other longstanding digital modes have been virtually deserted as everyone experiments and communicates using FT8. Developed by Joe Taylor, K1JT, and Steven Franke, K9AN, it is part of a software package download called WSJT-X that also includes other modes: JT4, JT9, JT65, QRA64, ISCAT, MSK144, and WSPR. And there is an additional mode called Echo for detecting and measuring your own radio signals reflected from the Moon.

FT8 is an 8-frequency shift keying (FSK) format using tones that are only 6.25 Hz wide. So an FT8 signal occupies a bandwidth of just 50 Hz. Some complex algorithmic calculations are going on behind both the message compression at the transmission end and the message expansion at the receiving end. It takes 12.6 seconds of the 15 second transmission period to transfer the message. There’s no room for rag-chewing or idle conversation here!

For many, it seems that the attraction of FT8 is its ability to establish reliable DX contacts across long distances using a structured compressed messaging protocol. Each over lasts only 15 seconds, exchanges include Maidenhead grid coordinates, signal reports and a ’73’. Most QSOs are completed in under two minutes, although in busy times it is common to find some parts of the QSO sequence being repeated over and over until the tightly structured sequence has been completed in order to qualify as a completed QSO. It is this speed and succinctness of the exchanges and the DX possibilities that appear to be attracting hams worldwide to this mode. Sometimes, I feel like I am involved in a full-on DX contest that runs 24 hours a day, 365 days of the year!

The two FT8 panels showing band activity on the left and received frequency on the right. Colour coding makes it easy to identify unworked countries, unworked stations, previously worked stations and stations worked in the current session.
Click on image to enlarge.

And for many hams not running high power, FT8 and some of the other modes in this package make it possible to enjoy DX contacts without the need for fancy power amplifiers and sophisticated HF/VHF beam antennas. Given the right propagation conditions, QRP (low power) operators can have their signals heard across vast distances. Indeed, FT8 and the other modes in the WSJT-X application has breathed new life into the radio hobby for those hams with restricted space limits for antennas at home, modest radio equipment setups, or who enjoy working lower power while participating in out in-the-field activities.

In the past two months, there were two DX contacts I made that stand out for me personally. The first involved a QSO here in southeastern Australia on a humble inverted-vee dipole using only 5 watts and making a QSO into Plymouth, Minnesota on 14mHz in my mid-afternoon with Hans K0HB, a distance of some 9425 miles (15,168 km). Not bad for the bottom of the sunspot cycle!

The second instance was a pleasing contact with Cliff, CT7ANG, in Sao Bras De Alportel, southern Portugal via the long path on 14mHz in the late afternoon. This was an LP distance of 13,910 miles (22,390 km) using 20 watts output into the same dipole. Undoubtedly, Cliff’s many-element beam antenna was probably doing all the work for me! But at least my signal was getting through the heavy QRM to his home station.

The FT8 spectrogram waterfall.

And what’s with this WSPR thing?

As I mentioned earlier, another mode in this software package is WSPR (pronounced “whisper”!) and stands for Weak Signal Propagation Reporter. Designed by Joe Taylor K1JT, WSPR has been around for about ten years now and is a four-tone frequency shift keying (FSK) with a bandwidth of only 6 Hz. It is described in the online WSJT-X manual as being a protocol “…designed for probing potential propagation paths using low-power transmissions. WSPR messages normally carry the transmitting station’s call sign, grid locator, and transmitter power in dBm, and they can be decoded at signal-to-noise ratios as low as -28 dB in a 2500 Hz bandwidth.”

Unlike FT8 and the other modes, WSPR is not designed for 2-way QSOs in the traditional sense. Think of it like a beacon that amateur radio operators can activate at any time for transmission in the ham bands right through from the LF, MF, HF and even VHF/UHF frequencies.

Initially, WSPR was designed to test propagation paths on MF and HF. It has enabled us to understand better the finer details of how propagation works, especially under challenging conditions. I have been amazed at how many WSPR signals I can monitor when propagation conditions are poor (even during periods of intense geomagnetic storm activity!) or when my local manmade RF interference has been high.

But for hams, WSPR is also useful for judging the effectiveness of your antenna system. If the signal you are transmitting at a specific power output is not being heard reliably by other WSPR monitors, then it’s possibly a good indication to check your antenna’s performance! There could be a fault somewhere in the feedline or with the antenna itself. I find this useful for WSPR especially helpful in knowing how well my signal is being received by others.

When monitoring the WSPR mode with computer access to the Internet, reception reports are automatically uploaded (optional) to a central database at http://wsprnet.org. So, straight after a two-minute transmission into my antenna, I get feedback by checking into WSPRnet’s map for a visual report of just how far my signal has been heard by the monitoring stations. I find this process and almost instantaneous feedback quite fascinating! It is astonishing just how far signals can travel using powers of, say, 5 watts down to just 100 milliwatts or even less!

Both FT8 and WSPR use only tiny portions of each ham band, and indeed only small portions of the allocated digital transmission parts of each band. Both modes use waterfall spectrograms to help you spot where signals in these tiny slices of spectrum. The WSJT-X application is free to download at https://physics.princeton.edu/pulsar/k1jt/wsjtx.html

Norbert VK5MQ is currently stationed on Macquarie Island, Antarctica using the call sign VK0AI. He is an avid user of the FT8 mode and quickly confirms to eQSL within minutes of the QSO.

So, what’s in it for a shortwave listener?

Well, even though you may not have an amateur radio licence, there is still much enjoyment to be gained from listening to these weak signal modes. Although the warbling sounds of FT8 do not make inspiring program content, to monitor and observe signals from all over the world arriving at your receiver and watch them being decoded by your computer holds a significant fascination for some listeners.

But monitoring and decoding digital signals is not something new for SWLers. Listeners have tuned into a variety of traditional modes such as RTTY, WEFAX, AMTOR, PACTOR, PSK31 and many other transmissions. Over the last few years, the Voice of America experimental digital transmissions has created considerable interest for listeners. Formerly known as VOA Radiogram, the name was recently changed to Shortwave Radiogram and expanded to include short transmissions from other broadcasters - the Mighty KBC and the Italian Broadcasting Corporation (IBC). Modes have included MFSK 16, 32 and 64, Olivia 16-500, 32-1000, and 64-2000, usually in the form of images and messages. The software of choice for these experimental transmissions has been the Fldigi family of applications.

You can send your reception reports or SWL QSL cards to hams in the hope that they might reciprocate with their own QSL card. A great way to do this is through the facilities of eQSL at http://www.eqsl.cc. Although I have only been on FT8 for a few months, already I have received some attractive eQSLs from keen SWLers.

As indicated earlier, these modes are great for establishing the effectiveness of your SWL antenna system. The frequencies set aside for FT8 communication are currently extremely busy for much of the 24-hour period - depending, of course, on when you are tuning the bands. For example, 160 and 80 meters are still nighttime bands, so you won’t hear anything much during the daylight hours. 40, 30, 20 and 17 meters can be active with FT8 signals during much of the day. And despite currently being in the depths of the sunspot cycle minimum, even 15, 12 and 10 meters can provide some fabulous openings using FT8. And this year, 6 meters has been very active during the summer months.

You will find FT8 activity on and around the following frequencies:
160m - 1.840 MHz;
80m - 3.573 MHz;
40m - 7.074 MHz;
30m - 10.136 MHz;
20m - 14.074 MHz,
17m - 18.100 MHz;
15m - 21.074 MHz,
12m - 24.915 MHz;
10m - 28.074 MHz,
and 6m - 50.313 MHz.

The WSPR frequencies can be located at:
160m – 1.8366 MHz;
80m – 3.5686 MHz;
40m – 7.0386 MHz;
30m – 10.1387 MHz,
20m – 14.0956 MHz;
17m – 18.1046 MHz;
15m – 21.0946 MHz;
12m – 24.9246 MHz;
10m – 28.1246 MHz,
and 6m – 50.2930 MHz.

Using FT8 and WSPR, you will find that monitoring the above frequencies is a great way to check how your shortwave listening antennas and feed lines are performing.

Another benefit mentioned earlier relates to signal propagation. Physics is physics, and the science of radio wave propagation still applies! But some interesting observations are showing that FT8, WSPR and the other weak signal modes can be more resilient under quite tricky propagation conditions, breaking through where other modes such as CW and SSB would fail. An article in the October 2017 issue of QST magazine entitled Understanding Propagation with JT65, JT9 and FT8 by Carl Luetzelschwaub K9LA explains this in greater depth.

The weak signal modes are also wonderful tools for discovering current propagation conditions. Perhaps reception appears somewhat poor when listening to your favourite shortwave broadcasters. A quick check of the WSPR transmissions may well confirm your observations. Hearing something unusual - a shortwave broadcaster that you don’t usually catch at a particular time or frequency? There could be enhanced propagation conditions currently underway. WSPR signals or FT8 activity from some regions of the globe could possibly provide an advance indication of this, too! As I have written in the past, learning about shortwave propagation can be a real aid to successful shortwave listening, adding valuable understanding about when, where and how signals arrive at our receivers.

Phill 3D2TS is very active on FT8 from Suva, Fiji. His home QTH is in New Caledonia but currently stationed in 3D2-land for the next two years.

Also, you can set up the WSJT-X program so that signals decoded by your computer are automatically uploaded to the PSKReporter (https://pskreporter.info/) and the WSPRnet (http://wsprnet.org/) websites. Your monitored observations add to the body of data collected each and every minute of the day, providing meaningful feedback to the amateur radio operators who check to see how far and to what parts of the world their low powered signals are being heard during a 24-hour period To participate in this exercise and you don’t have a ham call sign, all you need is some type of SWL call sign to identify yourself. In some European and Asian countries, the governing amateur radio body will issue SWL call signs, but in other parts of the world such as North America and Australia, there is no interest in allotting SWL calls. So you could apply for one from the Short Wave Amateur Radio Listening organization (SWARL) at http://swarl.org/. Perhaps you have one of those WPE or WDX calls from the old days! Failing that, just make up a call sign that identifies you as an SWL.

The Set Up

The installation of the software package is quite straightforward, and there are versions available for Windows, Macintosh, and various flavours of Linux. However, the setup for communication between radio and computer can be tricky and fiddly, especially if you have not had much experience with digital modes in the past. This seems to be the case more so for the transmit side rather than on receive. If you have previously installed and operated Fldigi successfully, then you will be on the road to coping with the setup for WSJT-X.

The problem is that a really successful setup requires some type of external interface (e.g. SignaLink USB or RigBlaster) or a similar commercial device. Most modern radios offer a 9-pin CAT jack for computer control. A growing number of transceivers (such as my Yaesu FTDX3000) also include a USB jack for CAT commands from the computer that has its own sound card for input and output of audio signals and transceiver control, so no external interface is required. All it needs then is to download the appropriate Windows or Mac driver.

Setting up the COM port, adjusting various data settings, and using the correct USB audio CODEC can be problematic in some situations. Setups between each brand and model of radio and differing computer platforms can be a minefield for some users. Here, the downloadable WSJT-X manual is very helpful, but failing that Google and YouTube are your friends! Not being thoroughly acquainted with digital modes, I had several nights of exploration, discovery and education before I could correctly marry up my FTDX3000 and my MacBook Pro laptop machine. But in the end, it was worth the pain.

Do you only have a small portable receiver, such as a Sony, Tecsun, or Grundig with no serial/CAT connections? Want to avoid all the challenges of a direct connection to your computer? You can still dabble in the FT8 experience by merely putting your radio near the computer’s inbuilt microphone. Or connect an external microphone to the computer and place it next to the radio’s speaker. Because these transmissions are audible tones, the WSJT-X program will pick up the signals and decode them for you. Remember to listen in upper sideband (USB) mode. And, you will still get the waterfall. You won’t get any decodes of sub-audible signals (the really weak ones), but as long as you can hear the gentle warbling sounds, it should decode some stronger signals quite well.

If your receiver does not have CAT facilities, a simple acoustic coupling can be made by placing the receiver close to the computer's microphone.

An excellent introduction and primer to the WSJT-X software appeared in the June 2017 issue of The Spectrum Monitor (TSM). Entitled Using Weak Signal Software to Reach for the Sky! by Robert Gulley AK3Q, this 6-page article is well worth reading. Because it was published just before FT8 had been added to the suite of digital modes, it includes just WSPR, JT65, JT9 and the other modes. But the beautiful thing about the WSPR-X application is that once you have one mode set up, pretty much all the protocols use the same settings. If you don’t have the June 2017 TSM magazine in your digital library, you can order it for just $3 from The Spectrum Monitor website.

Another valuable resource is the FT8 Operating Guide by Gary Hinson ZL2iFB, which can be found at http://www.g4ifb.com/html/ft8_tips.html. Also, check out Joe Taylor’s excellent presentation called Work the World with WSJT-X at the 2018 MicroHAMS digital conference on YouTube at https://youtu.be/233HQs_8JGQ

Finally, I have made a short YouTube video showing the setup in my radio shack using the Yaesu FTDX300 and an Apple MacBook Pro laptop, which you can find at https://youtu.be/98MRSppeJno.

Good luck with your explorations into the world of digital communications.

73 and good DX to you all!

Rob Wagner VK3BVW