Digital Modes Overview
Now you have had some fun with your Xiegu G90 HF Transceiver, possibly had a few QSO’s, checked how well the inbuilt Antenna Tuner works, you want to sample the Digital Modes that everyone is talking about.
This article initially was short, but it started getting quite large, so it has been setup as several articles, which I recommend reading in the following order
- Xiegu G90 & Digital Modes (the page you are on)
- Xiegu G90 & the CAT Cable
- Xiegu G90 & the CE-19 & Cabling
- XIEGU G90 & FT8
In Australia, whether you hold a foundation, standard or advanced licence, you can take part in using Digital Modes. Generally what you will need is
- Computer (Can also be an Single Board Computer like a Raspberry PI)
- Interface (Which also means cables)
You most likely have a transceiver, particularly as you are interested in Digital Mode Communications, and hopefully you have a Xiegu G90, as that is what these articles are about (but I fully recognise that you might have ended up on this page as you are interested in Digital Mode Communication, and want to apply the concepts of what is in this article to your model of radio.
If you have the Xiegu G90, then you have the Transceiver. All you need is a low end computer, an interface and some software, which we discuss below.
That 10 year old computer that you have gathering dust under the desk may not be suitable, but you actually don’t need much. Ideally a workstation that is capable of running Windows 10 is ideal (most I3 or I5 are capable) with 250Gb hard drive, and at least 4Gb ram or better with 8Gb. Now this does not need the latest and greatest, in fact most computers that have been built in the last 3-5 years would be suitable, which also means that the majority of computers at the auction houses (which recycle many of enterprise or government computers) have them at this age. Depending on the the auction house, you should be able to get one at $20-$50. Even if you get an I3, no operating system, you could install Linux on it, and it will more than meet the needs.
As I mentioned above, even a Raspberry Pi 4b will do the job nicely and have seen others that have implemented it on lower end Raspberry Pi’s as well.
Just on other point, depending on the Interface that you use, you may need to make sure that the computer has Audio Input and Output ports or a spare USB port to plug in a USB Sound Card
Interfaces – Common and Popular products
Now we get to the slightly harder part, selecting an interface. A few models that appear to be popular are as follows
So let me be very clear, you do not need a CE-19, or an XGGComms Digimode-4 or a Signalink, as you can build your own interface if you want (and combine that with your CAT cable). However each of these interfaces as some desirable features such as being prebuilt, or provide isolation between your rig and your computer (at least on the audio). The Signalink has the sound card built in and adjustable. Its up to you to look at the features of each and make your choice.
I personally went for the Xeigu CE-19, mainly as it was the interface from the Transceiver manufacturer, and I was fortunate to get it at a decent price, however you have to make up your own audio cable to fit between the rig and the CE-19 unit. I have also read decent reviews on the XGGComms Digimode-4 device as well, but a little more expensive (but less wires for portable operators) and ready to plug in.
When selecting an Interface for Digital Modes, you need to take in the following considerations
Now as we said previously, Rig Control or CAT is not a pre-requisite for Digital Modes, however if you want to make it easier for logging, easier to work with some of the other features of the software, then you may want to make Rig Control one of the items that you determine your selection. It should be noted that the CE-19 does not provide CAT control, this is still done by the CAT Cable that comes with the Transceiver. XGGComms DigiMode-4 does provide CAT Control, and the Signa Link does not provide CAT control (you would need to use a separate CAT Cable).
Audio In and Out
Now this is the primary functionality that is used for a successful QSO with Digital modes. First of all, your computer will accept audio from your transceiver and decode it, placing the text on the screen through one of many applications. Likewise, Your computer will take your text and encode it and send it through the Transceiver. What this means is that the audio interface may make or break your transmission. An interface that has hum on it, will cause the transmission to fail. You may like to try with your PC’s inbuilt sound interfaces, and should they prove to be an issue, then you could look at a decent USB Sound Card. Now one thing I will add is that the SignaLink USB has the Sound Card built into the unit, so there is no need for a separate sound connection. Now I mentioned trat the XGGComms Digimode-4 provides CAT control, well it also has a Sound Card built in as well.
Ok, this is another function that you need to check is covered by whatever interface that you decide to use. Now we are fortunate, that the G90 has a VOX function that we can enable, so when digital communications is sent, the radio will automatically turn on the Push to Talk function, and transmit, so you don’t necessarily need the PTT connection. However, if you had a PTT, why not use it, and I believe all the interfaces I have mentioned above have PTT capability.
First and foremost, the FL range of utilities is probably the first items to start with. You can obtain them from the W1HKJ website. You will find versions for Windows, Linux, Mac etc. You don’t have to start with these applications, but they are relatively easy to understand, have a large user base and you will find forums, groups.io and even Reddit with healthy discussions and assistance on the suite of FL applications
Once you have got the software working, you can then start looking further afield. You may even find that you want to run them on a Raspberry PI. Having them running and tested on a Windows PC, you know your understanding is correct and one less issue to deal with as you move to a new platform or new software.
Whilst the FL suite of programs each perform a function (e.g. FLRIG does CAT control, FLDigi does Digital modes) they integrate with each other. You may find other software has implemented a tighter integration. Products like Ham Radio Deluxe and Log4OM, N1MM, focus strongly on the Logging function, providing rig control and digital communication software to round off their product offering. It really comes down to whether you are going to be heavily involved in contests, SOTA / POTA, or just casual contacts. Again I recommend getting all the basics under your belt, and once you know what you need and what you want, then look at what each product offers.
Now I have spoken about the FL Suite, and I do believe you should have some experience with the applications. You may find other programs can communicate through some of these applications.
Now there is a lot more to digital modes that what I have talked about here, and really it’s impossible to have one document cover everything about Digital modes. What you wish to do, is entirely up to you.
However, I suspect you are interested in WSJT-X (Weak Signal Communication) (FT8 / FT4 / JT65) and WSPR (Weak Signal Propagation Reports). For many getting into Digital Modes, these items I have just mentioned, are probably your primary interests. For this reason I have provided more information in this additional guide on what it is all about.
So, it is not all that hard. In effect, our main consideration is the ability to receive and transmit over the air, which we do using either your computers sound card or the sound cards built into the Signalink and XGGComms interfaces. That is ultimately what you need to start working in the digital modes. The only other critical part is a transceiver with a VOX Capability or the ability to control the PTT, so when your computer provides the tones, that the radio will start transmitting them.
As for the CAT control, I believe it is nice to have, but not essential. I use it, but it does not mean that you have to or want to.