Reducing the Cable Mess | Digirig Mobile

Hello Operators.

We are always on the lookout for audio & CAT control interfaces offering pragmatic benefits for the off-grid, EMCOMM and field radio operator.  We’ve seen the ZLP MiniproSC, XGGComms Digimode-4, the DRAWS Hat for the Raspberry Pi, and even made our own audio interface cables from time to time. Most of you already understand how needless wiring, weight, and mostly empty interface boxes annoy me to no end.

The big players like Tigertronics simply don’t understand the need for smaller, lighter all-in-one audio and CAT control interfaces. They don’t understand when the audio interface is as big as the radio, we’re doing something seriously wrong!

The big players like Tigertronics simply don’t understand the need for smaller, lighter all-in-one audio and CAT control interfaces. They don’t understand when the audio interface is as big as the radio, we’re doing something seriously wrong! For this reason, I’ll take every opportunity available to promote products helping reduce system size, complexity and the wire mess.


Digirig mobile v1.6

This is the Digirig Mobile. It is the smallest all-in-one audio and CAT control interface available today. For the past few months I’ve been testing the Digirig mobile mostly QRP with a Super Antenna MP1, 5 watts on a Surface Go 2. The tests have run Winlink, JTDX, JS8Call, … with the Lab599 TX500, Xiegu G90, Xiegu X5105, and Yaesu ft-81x. The performance and benefits have been astonishing, to say the least.

The Digirig mobile is an extremely small audio and rig control interface, with a single USB cable. It supports most QRP radios requiring external audio and CAT control facilities. In the above image, you see the Digirig mobile wired for the Xiegu x5105 and Lab599 Discovery TX-500. It’s also been working flawlessly with my Xiegu G90 and Yaesu FT-81x. We’ll even give it a go with my Vertex Standard VX1210, once I make the cable.

Winlink with Xiegu x5105 and Digirig mobile with Surface Go 2

For those of you who have been around the channel since the beginning, this is roughly the size of a wolphilink interface. Perhaps even a bit smaller. Unlike the Signalink, it has no external audio controls, which is fine by me. What the Digirig does have is an in-built audio interface in addition to rig control. This is something we have only seen with the XGGComm Digimode interface.

As with other interfaces seen on the channel, I set up the audio input and output baseline levels on the radio to about 50%. Next, I adjusted the baseline audio I/O levels for the digirigs internal audio interface in OSs audio settings. This too is about 50% to start. Next adjusted output gain slider in WSJT-X, JTDX, JS8Call, fldigi… to good ALC. To adjust incoming audio levels and waterfall gain, readjust input gain in OS audio settings for good decode, then fine-tune using RF gain, preamplifiers, … Levels are usually set once then never touched again. This generally remains true until something drastic happens with the station eg antenna change, coax change, … Small atmospheric changes also cause us to readjust audio I/O. RF gain is usually enough to compensate.

Since the Digirig interface has an in-built audio card embedded, We won’t find ourselves transmitting OS notifications over the air. Moreover, the settings are saved even if the Digirig Mobile is unplugged, then plugged in again. The settings are saved independent of the computers own internal sound card. This means we are not setting up the interface every time it is removed then plugged into the computer again. We start where we left off previously. This is also true for the com port, which remains consistent unless you change it. These persistent settings allow us to run multiple with multiple radios simultaneously on the same computer. In the next example image, I’m running two different radios, with one computer, two different modes.

So far I’ve tested this on Windows 10 with Lenovo Yoga laptop & Microsoft Surface, the Raspberry Pi 4, and a Linux Ubuntu laptop. On Windows 10, the drivers needed updating, through Windows update, before the device was recognized. Once those drivers updated, it was Plug and Play. So be certain you’ve done a windows update, before plugging this device in for the first time. On the Raspberry Pi and Linux Ubuntu, the Audio interface just popped up, ready to use.

Connections tablet or laptop

Connections between the Digirig Mobile and your tablet or laptop are incredibly simple. For the Microsoft Surface go tablet or my Lenovo Yoga laptop I’m using a single USB-C from the Digirig v1.6, or Micro USB for the v1.5 Digirig cable between them. For the surface and v1.6, a dual USB-C PD to USB-C cable. Same for the Yoga, a dual USB-C PD cable. Buy quality cables! No need to think it to death, Digitig makes excellent cables. Reach out to Denis and tell him what you’re trying to do. He’ll suggest the right cables from his shop.

Audio Interface Advice

It’s always good practice to have a dedicated audio and rig control interface for data Communications on your computer. This is true even if your computer has an internal sound card. One of the most frustrating aspects of operating data modes is hearing notifications from an operators computer over the air, along with their data transmissions. Having a dedicated audio interface with notifications disabled on that interface allows a nice clean trouble-free experience for the operator, and those listening to his or her transmission.

Tradition gets in the way of progress

One example of traditional audio interface design is the Signalink. It is the industry standard for audio interfaces, yet lacks rig control capabilities despite its size. Even with its reasonable performance, it’s ridiculous how a Signalink can still be larger than the QRP rig we would like to use it with. Again there is no complaint about its performance, just the size of it for the field radio operator. The Signalink is just one example of the longstanding attitude of audio interface manufacturers, refusing to design smaller more capable audio and rig control interfaces. Until this changes, we have to look elsewhere for more pragmatic designs.

For the portable data operator, a small single wire interface is the apex of any wired configuration. Unfortunately, portable radio manufacturers like Elecraft and Yaesu are still unwilling to implement the All-In-One Single USB (audio and CAT control)  cable operation as seen in the Icom IC-705, mcHF, Xiegu 6100. We can still come close by removing the large cumbersome wire looms and interfaces manufacturers insist on delivering, by augmenting our radios with a Digirig Mobile.

Reach out to Denis at Digirig. He is very responsive, constantly making improvements and adding new radios to the list of rigs the Digirig Mobile is compatible with.


Lots of effort goes into these posts. Researching each component, software application, pragmatic field testing. When you see these posts, the mistakes and blunders have already been filtered out. If you find any value in that, share this post and/or buy me a rootbeer.

73
Julian oh8stn
YouTube http://www.youtube.com/c/oh8stn
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9 Comments

  1. Thanks for the clear and thorough overview, Julian. This type of straightforward information is always useful. 73, garu

  2. Great write up Julian! I picked one up for my tx500 as soon as I saw the first post about it show up online and am extremely happy with it.

  3. Shortly after ordering the Digirig, etc., this post popped up. Enjoyed your report and look forward to using it myself.

    As someone that uses test equipment on the bench, I like the bigger sizes for benchtop. Cables don’t pull the equipment around. For portable, it is another story. Small is good but only as long as it is robust. I am hoping this is robust.

    Thanks for your report!

  4. Anyone have a schematic for building a cable that will connect the Digirig to a Kenwood TS-440S?

    TNX es 73 de David AE4LH

    • No I sold the ft-891 to finance the PA 500 amplifier. I’m not sure if they would be much value in this for the ft-891 since the ft-891 has cat control over USB already. You could use this for audio alone as it’s still a much smaller audio interface then a signaling for any other audio interface available. You still have two USB cables coming out though

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