What is Digirig?
The Digirig Mobile is an essential digital modes interface for amateur radio, compactly integrating an advanced audio codec, versatile serial CAT control, and precise PTT switching through a single USB connection. This innovative device dramatically simplifies your ham radio setup by reducing cable clutter and ensuring seamless integration with a wide array of transceivers, enabling reliable and effortless operation for all popular digital modes across Windows, MacOS, and Linux, whether you're in the shack or on the go.
For those seeking a more streamlined solution, the Digirig Lite offers a minimalistic version of the Digirig Mobile. It shares the same high-quality audio codec for crystal-clear digital mode audio, but simplifies the design by omitting the serial CAT port, making it ideal for setups where only audio and PTT control are needed.
Choosing a Digirig Model
Below is a side-to-side comparison of the features for the Digirig interfaces.
| Hardware Overview | ||||
| Feature | Digirig Mobile | Digirig Lite | Digirig DR-891 | VOX PTT Cable |
|---|---|---|---|---|
| Form Factor | Aluminum extrusion, about size of the 9V battery | Shielded cable ~12″ long with ferrites and ABS plastic enclosure in the middle | Aluminum extrusion, about size of the 9V battery | Shielded cable ~8″ long with PCB inside of the molding in the middle. |
| Computer Connection | Female USB-C, requires data capable cable (sold separately) | Male USB-C or USB-A with included adapter | Female USB-C, requires data capable cable (sold separately) | Male 3.5mm TRRS headset jack with CTIA pinout |
| Transceiver Connection | Female 3.5mm TRRS for audio and PTT, Female 3.5mm TRRS for serial and 3.3V power (optional), requires audio and optionally serial cables (sold separately) | Female 3.5mm TRRS for audio and PTT, requires audio/PTT cable (sold separately) | Female 3.5mm TRRS for audio and PTT, Female 3.5mm TRRS for downlink USB connection | Female 3.5mm TRRS for audio and PTT |
| Cables Included | None included (Required: data capable USB-C cable, audio/PTT cable; Optional: serial cable) | None included (Required: audio/PTT cable) | Audio/PTT cable, optional downlink USB cable (both included) (Required: data capable USB-C cable - not included) |
None included (Required: audio/PTT cable) |
| Audio Interface | Soundcard | Soundcard | Soundcard | Uses internal soundcard of the phone or tablet |
| Serial/CAT Control | Supported for CAT and/or programming. Serial port lines can be configured for Logic Levels, RS-232, CI-V, TX-500. | Not supported | Supported, via pass-through to transceiver’s internal USB-to-serial bridge | Not supported |
| PTT Methods | PTT by RTS of COM port, PTT via CAT command | GPIO3 (RA-Board), Active VOX on the right audio channel. Each can be disabled via solder pads. | PTT via CAT command, GPIO3 (RA-Board), Active VOX on the right audio channel. Each can be disabled via solder pads. | Passive VOX on the right audio channel |
| Configuration Pads | Serial levels, attenuator (disabled by default), 3.3V output (disabled by default) | PTT by VOX (enabled by default), PTT by GPIO3 (enabled by default) | PTT by VOX (enabled by default), PTT by GPIO3 (enabled by default), attenuator (disabled by default) | None |
Simplified Selection
Here are some simplified steps to help you choose which Digirig model is right for you.
My radio has USB port (All except FT-891)
The USB port in the back of the transceiver usually means that the radio is equipped with an internal digital modes interface and you don’t need Digirig. All that required is a USB cable directly from the transceiver to the computer. This is the case with popular models such as ICOM IC-705, ICOM IC-7100, ICOM IC-7200, ICOM IC-7300, ICOM IC-7600, ICOM IC-7610, ICOM IC-9700, Yaesu FT-991A, Yaesu FT-710, Yaesu FTDX10, Yaesu FTDX3000, Xiegu X6100, Xiegu X6200 etc.
The notable exception to this list is Yaesu FT-891 which uses USB port for internal USB-to-serial bridge (CAT control), but does not have an onboard sound interface; see next recommendation. Other situations where you would would bypass the internal interface is when it has failed (serial port, sound card or both) or you need better soundcard performance than offered by the internal codec (e.g. for VaraFM wide).
My transceiver is Yaesu FT-891
This one is easy: pick Digirig DR-891. This model is specifically designed for your radio, utilizing maximum interfacing capabilities. There never was and likely never will be a better option. With the fallback PTT methods this also includes support of the apps on the mobile platforms as long as your phone or tablet can accept a USB connection.
I'm going to primarily operate using iOS or Android devices
The mobile platforms, especially iOS and to smaller extend Android, are quite restrictive when it comes to the access to the custom hardware. Because of that the support for some PTT and CAT control methods may be difficult to implement. On the other hand the sound cards are the standard accessories and don’t require any special accommodations.
Some mobile apps for ham radio support PTT by RTS, some apps support PTT by GPIO3, almost none support PTT by CAT, but all without exception will work with PTT by VOX. PTT by VOX implementation relies on the audio signals and doesn’t require any support from the software. When the PTT tone or the outbound audio payload is present, the interface keys up the transceiver for transmission automatically. This makes Digirig models with VOX support (Lite, DR-891, VOX cable) most widely compatible.
PTT by VOX inherently has a reaction latency, which is minimized in Digirig but still may require adjustments of software settings such as no-op preamble. If there is a choice of PTT options, the explicitly timed methods such as by RTS, GPIO3 or CAT should be prioritized. VOX PTT by tone on the right audio channel is next best and VOX PTT by payload is the last.
If your smartphone or tablet can accept USB connection directly or via OTG dongle then pick Digirig Lite. If it only has 3.5mm headset jack (directly or through an adapter) then your only choice is VOX PTT Cable.
I only plan to interface basic HTs and mobile radios
None of these radios typically support serial CAT control so Digirig Lite is a cost effective and compact option. All you need is audio + PTT and Digirig Lite delivers. There is a use case for Digirig Mobile’s serial port even with the basic radios and it’s for the programming of the internal memory. In some cases this may require homebrew cables, in others cable is included in the kit (refer to cable listings for the info).
My radios support CAT control
The only model capable of serial CAT control at the time of posting is Digirig Mobile. Make sure to select the correct port configuration when ordering [click here for more info]. You may need multiple units in different configurations if you have multiple radios that support different electrical standards for the serial ports. In every case the serial CAT is an optional convenience feature and you are not required to use it if you are setting your radio manually.