Amateur Radio Guide – Digital Mode – FT8

Topic	Digital Modes
Subtopic	FT8
Equipment Required	Computer + Transceiver Capable of Computer Control
Alternative Equipment that can be used
Bands	80m to 10m (Predominant Bands) 6m to 23cm (See Note 3)
Power required for adequate operation	Low Power < 10 watts
Antenna Required	Minimum – Dipole / Vertical / EFHW / Random Wire
Document last reviewed and updated (reviewed each year)	8th August 2022

Overview :

FT8 is an extremely weak signal digital Narrow bandwidth Communication, that uses a minimum amount of data exchange to complete a QSO. It was created by Joe Taylor, K1JT and Steve Franke, K9AN. The QSO is structured swapping details like Callsign, Location, Signal Report and 73’s. The whole QSO is generally completed in 90 seconds.

It should be noted that it is not intended as a conversational protocol, there are other protocols for that. What this does, and what it has done already, is provide a very simple reliable communications protocol that works well even in the lower ends of the Solar Cycle. It breathes some live back into Amateur radio during the DX voice quiet periods, and it can be just as exciting as voice, working the world for Awards. Another great advantage is that even if your rig is only QRP, or your Rig cost you $200, in most cases your system is capable of working the world on FT8.

Another advantage with Digital modes is that there are reporting tools that can be used such as PSKReporter.info. So almost all the Digital Mode connections that have been monitored, are available view via this website. Again in the quieter periods of the Solar Cycle, you can be honing your skills, which can including understanding effects on propagation, improving your antennas, improving your feedlines, understanding what modes are popular and where they are used and what times. Go back 10-20 years, and this wasn’t available….you made an improvement to an antenna, and your best feedback was possibly another ham giving you feedback. Now you can test and watch 10-20 stations in Japan hear you on the old antenna and with the new Antenna watch this number increase to 50. Very clear feedback indeed.

One of exciting parts of FT8, and everyone has witnessed this, that with a properly configured transceiver and audio connection, you may not be able to hear the signal underneath the noise floor and QRM, but so many times, your start the software and transmissions come up on the screen. If you are a Foundation licensee limited to 10 watts, using a compromised Antenna setup, dealing with QRM, and feel you are not getting the return for your effort, then give FT8 a shot, even make this your focus whilst you learn the craft.

Just before you get started FT8 is capable of being run on any frequency, as long as the band plan caters for it, and you are not creating interference for other operators. However having said that, if you are going to use FT8 off its normal frequencies, you are going to have to pre-organise this ahead of time. This is why there are set frequencies and these frequencies are :

160m	1.840 MHz
80m	3.573 MHz
60m	5.357 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
6m	50.313 MHz & (50.323 MHz – DX only not inter-continent)

You are probably wondering why the 2m and 70cm frequencies are not there…On HF these frequencies are within the band plans of most countries, or they have been established for a while. Especially with 2m and 70cm, the band plans very widely between WARC regions.So have a look around the web for the frequencies being used in your region.

You should also be using FT8 on Upper Side Band (USB). Especially on the lower bands, where you would normally select Lower Side Band (LSB), you need to use USB, even though it goes against the grain….If your radio has a data mode, then select that, usually you might have DATA-U, basically Data Upper Side Band.

If you are not sure if your receiver can receive FT8, select one of the frequencies above and list for a high pitched “carrier” or “tone”. This will normally be the FT8

Finally one more concept, each QSO is utilising 50Hz of occupied Bandwidth. What is showing on the WSJT-X waterfall however, is a representation of the signals present in the audio output, which is typically 100 Hz to 3300 Hz, so you are watching a number of QSO’s taking place. In the further reading section of this article, read the FT8 Tips document that has been linked as this explains a lot more how you can use this waterfall to increase your chances, and also when not to waste your time.

Software

The main software for FT8 is WSJT-X which was initially written by Joe Taylor (K1JT) but it is now open source and developed by a small team. Just a reminder that you will see this program show up as it is also used for FST4, FST4W, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, and WSPR, as well as Echo.

WSJT-X –https://physics.princeton.edu/pulsar/k1jt/wsjtx.html (Windows, Linux, Macintosh)

Alternatives

JTDX – https://sourceforge.net/projects/jtdx/ (Windows, Linux,

MSHV – https://sourceforge.net/projects/mshv/ (Windows, Linux)

The recommendation is to utilise WSJT-X until you have a good handle on the application, however some interesting features are being used in JTDX that are worth a look at  to see if they suit you, but understand WSJT-X first.

Hardware

The absolute requirement is that you will need a computer, whether it be Windows, Linux, Mac, and it can be a Desktop or a Laptop.

Ideally the transceiver needs computer control built in (generally CAT) and built in Sound Card. Examples of these transceivers are

Icom	IC-9100	IC-7300	IC-7610	IC-705	IC-7100
Yaesu	FT-DX10	FT-DX101D	FT991	FT991A
Elecraft	K3S	K4
Xiegu	X6100

Now this list is by no means exhaustive, and to provide you every Digitally capable radio is not the purpose of this article. These represent some of the popular radios that have support Digital Modes with something as simple as USB Cable between the radio and the computer and are optimised for Digital activity.

Now if you don’t have a model listed above, it is definitely not the end of the road for your digital aspirations. There are a large range of radios that have support from other third party or the manufacturers own products such as Digirig, Signalink, Xiegu’s CE19, RigBlaster, Tigertronics, RigExpert, MFJ-1204. Again this list is not extensive, but lists the more popular models. These units will take a transceiver that has the basic CAT control or at least PTT / VOX control, take the basic audio from the transceiver and get it to the interface levels required for the computer and its software. It is by no means a compromise, just takes a little more effort to get the sound volumes right, and make sure interfacing is working correctly. Just a word of note, do your research on what interface product will suit your transceiver best, confirm what cables you need (as most have the base unit and then a set of cable to suit the various transceivers, and also check on how they control things like transmit. Do they use CAT control, or do they use PTT or VOX. On some transceivers, PTT is more reliable than VOX.

Now I could start to list all the radios that are supported by WSJT-X, but at 260+, it would not be up to date for long and again not the purpose of this article. My recommendation is download WSJT-X, install it and go to the settings page, XCVR and drop down the RIG list to see if your rig is there (Like the image below). If it is, then there is likely that your rig has a direct USB interface, or there is an interface solution available like the earlier Xiegu units.

Finally, even if your rig is not on this list or many of the radios that are suitable are not in your budget. Many of the entry level transceivers are now incorporating Digital Interfaces such as the examples below (but there are many more)

QDX – Digital Transceiver – https://qrp-labs.com/qdx.html $US69
USDX Transceiver 8 Band Radio SDR All Mode (Aliexpress etc) $US160

These transceivers are only 5w or 10w, but that is all you need.

If you are keen to be involved in this facet of Amateur Radio, there is really no excuse.

Summary

It would be fair to say that has offered a new facet to Amateur Radio, one that can be utilised when the Solar Cycle is not at its peak. Whilst it involves a little amount of work and possibly equipment procurement to be able to use FT8 modes, it needs to be stated, that you are also opening up further opportunities using the same equipment to use and experiment with the other digital modes, which include FT4, FST4, FST4W, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, and WSPR, as well as RTTY, WEFAX, SSTV, CW, PSK and much, much more.

What’s even better, you don’t need the best transceiver, and you definitely can get by with a compromised antenna. This is a great solution for HOA restricted operators running hidden antennas.

Further Reading and Expansion

FT8 Operating Tips – https://www.physics.princeton.edu/pulsar/K1JT/FT8_Operating_Tips.pdf – very well written document – great follow on from this article

WSJT-X User Guide – https://physics.princeton.edu/pulsar/k1jt/wsjtx-doc/wsjtx-main-2.5.0_en.html – written by Joe Taylor

Amateur Radio Guides – FT4

Amateur Radio Guides – Digital Middleware

Amateur Radio Guides – PSKReporter and other reporting tools

Amateur Radio Guides – WSPR

Notes

Note 1:

FT8 and FT4 are dependent on your computer being very accurate, and should be Synced with an NTP time source. Your time should not be out of sync any more than 0.4 seconds. Anymore than this, and you will find it will impact your contacts.

Many people have reported that Windows built in NTP time client can have issues syncing better than 0.6 seconds. Many FT operators are using applications like

Meinberg NTP Package – https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable

Dimension 4 – http://www.thinkman.com/dimension4/download.htm

There are probably many others as well, and the current preferred option is Meinberg. I have also personally used Dimension 4 as well, but it is true it has not been updated recently and may have issues in certain environments. When you are using FT8 and you are receiving contacts, look at the DT column. This should show between 0.0 and 0.1 in this column for most of your contacts. This is the Difference in Time in seconds between your machine and the remote operator.

Note 2:

WSJT-X will communicate directly with Transceivers and selected interface hardware. However, WSJT-X will also communicate via middleware applications like HAMLIB, FLRIG, OmniRig. Use of these Middleware applications extend past what this article is about. However, you will find that there is an Amateur Radio Guide that discusses the use of these applications in more detail, particularly the suite of Digital applications written by W1HKJ.

Note 3:

You will probably look at the bands are listed as 80m to 10m being the predominant bands and in Australia this is probably correct. A good use of PSK Reporter is to look how many operators are using 6m, 2m, 70cm and 23cm in Australia. These operators a considerably less in Australia. This is not to say that they are non-existent, but very few and far between. Part of this reason is that especially in these bands, the line up of frequencies available for digital modes in WARC3 does not line up well with WARC 2 and 1. This is why you will see plenty of 6m FT8 in Europe and the U.S. and similarly for the other bands in the UHF/VHF.

Due to Australia’s distance, the VHF and UHF bands have a very limited distance compared to the HF bands, so contacts whilst again not impossible with the right conditions and antennas and power, are few and far between.