Introducing the UDRC

Universal Digital Radio Controller

Here at NW Digital Radio we are always looking at ways to enhance digital communications for the radio amateur. As we have been marching forward with the development of the UDRX-440 there have been a few products that have come to market both from us and from other manufacturers.

When designing the UDRX-440 we wanted to enable D-STAR voice communications and designed a daughter card to provide the AMBE vocoder. We choose the DVSI AMBE-3000™ chip which has the potential of providing superior voice reproduction on D-STAR, but also supports AMBE+2 which is used by other radio standards such as DMR, NXDN, Yaesu Fusion, APCO P25 Phase 2, … We created the DV3000, which is available as a standalone product along with the open source AMBEServer to make AMBE vocoding available over a network. This Raspberry Pi shield rapidly gained a following and hundreds are now deployed around the world. Later, we created a USB connected version of this device called the ThumbDV™, which has opened up AMBE vocoding to hundreds of additional users.

When Yaesu offered their new DR-1X Fusion repeater to clubs for $500  (updated information), the Northwest Digital Radio Club (not part of NW Digital Radio company) purchased one and put it on the air in Edmonds, WA as NW7DR.  The half rate digital voice is very good and the full rate voice is excellent. It wasn’t long before John (K7VE) looked at the external accessory adapter and wondered if the repeater could also do D-STAR. After considerable research and experimentation using a Raspberry Pi B+/2 for control and a DVRPTR V1 GMSK modem it was discovered that the DR-1X made an excellent D-STAR repeater. By comparison, John’s Kenwood based repeaters often run significant BER (bit error rate) on receive, at one location the Kenwood runs around 7+% BER, while the DR-1X is at 0%. (The repeaters are co-located and both use the DVRPTR V1.)

At first, the experiments ran into a known lockup condition when using an external controller in combination with Yaesu Fusion Digital mode. With the latest generation firmware the DR-1X is able to provide D-STAR, Analog, and Fusion Digital all on the same channel on a per transmission switched mode.  Mode control is accomplished using GPIO pins on the Raspberry Pi.

NW Digital Radio looked at the Raspberry Pi control system and soon decided that a combination control board with integrated CODEC could be built as a hat for 40 PIN GPIO headers on the Raspberry Pi and thus is born the Universal Digital Radio Controller or UDRC.

With the addition of the UDRC, the DR-1X will operate in these configurations. (WIRES-X requires a Yaesu HRI-200 attached to an external radio)

  • With the latest 1.00 family of firmware on the DR-1X
    • D-STAR/Analog
  • With the latest 1.10 family (after December 2015) on the DR-1X
    • D-STAR/Analog
    • D-STAR/Digital Fusion
    • D-STAR/Digital Fusion/Analog

The UDRC does not transcode between D-STAR and Fusion, it allows the DR-1X to repeat D-STAR transmissions and use the ircDDBGateway to communicate with stations, linked reflectors and repeaters, STARnet Digital Groups, etc.  Analog, Digital Fusion, and D-STAR are switched at the repeater on a per transmission basis.

The UDRC is designed as a simple to install addition to the DR-1X, however, NW Digital Radio has kept the experimenter in mind by providing various headers to allow straightforward hardware modification for integration with other hardware and applications. The built-in CODEC also will be available via a amateur packet radio standard mini DIN-6 port for software developers to adapt other modes, e.g. Packet Radio, VOIP (Asterisk/IRLP/Echolink), Codec-2, … Additionally, all GPIO and audio pins are available as solder through pads.

Share your application ideas on the UDRC group.

Estimated price for the UDRC is $89.95


DMR / D-STAR Gateway

The Germans have done it again!

From the folks that brought us the ircDDB network, we hear from Hans-Jürgen Barthen, DL5DI, that there is now a gateway between D-STAR (DCS Gateways) and Hytera DMR Repeaters using the AMBEServer with either the PiDV™ or ThumbDV™.  This gateway is in use at a handful of DMR repeaters in Germany and Austria with systems soon to be implemented in Sweden and Switzerland.

You can download executables for the gateway and combine with the AMBEServer to create your own gateway. The software does D-STAR callsign to DMR radio ID mapping and transports audio between networks using the Hytera API.

Another step toward Universal Digital Radio from the community of amateur radio developers using products from NW Digital Radio.


Manufacturing Reliability Data

We have now shipped over 300 PiDV™, and the ThumbDV™ will soon pass it for units delivered. There are currently 200 more units in process.

Out of the Box MFG, our local assembly house in Renton WA, does a great job on their SMT line which includes automated optical inspection or AOI. We physically tested all of the first 100 units and found 1 failure, which was attributed to a bad AMBE3000 IC, probably due to hot plugging the board during test.

At this point we stopped functional testing and now rely on AOI to flag any assembly issues for operator inspection or remedy. We have had one working unit returned as suspect but it turned out to be a failed R-Pi and the PiDV™ was returned to service with no charge to the customer.

I want to thank Chad, Paul, Brian and all of the people at Out of the Box for their hi-quality and reasonable cost assembly services.

Bryan – K7UDR

Statement of Origin:

The PiDV™ and ThumbDV™ are assembled in the USA by Out of the Box from globally manufactured components obtained thru Dig-Key and Mouser. The PCB Fabs are made in China.


ThumbDV™ Passes FCC Approval

Because the ThumbDV™ attaches to a computer using USB, it is clearly a “Computer Peripheral” as defined by the FCC and is required to meet the Part 15 Subpart B standard for conducted and radiated emissions.

We sent a sample unit to Nemko-CCL, an accredited test lab in Utah, and they performed testing to the following standards:

  • EU: EN5022:2010
  • USA: FCC Part 15, Subpart B
  • CAN: ICES-003, Issue 5
  • AUS/NZL: CISPR 22:2009

After passing all tests, a Declaration of Conformity was issued by Nemko-CCL and as of today all units are shipped with a sticker on the back.

ThumbDV Passes FCC 15b

Do the ThumbDV™ and PiDV™ Sound Better Than the DV Dongle?

A number of customers have reported anecdotally that the ThumbDV™ and PiDV™ (formerly DV3000) have good audio, but is that just perception or is there some truth to it? I spoke with Rich Kovars, Applications Engineer at DVSI, who talked about the ThumbDV™/PiDV™ AMBE-3000 chip vs the Dongle’s1 AMBE-2020.

From the DVSI Website:

“DVSI’s AMBE-2020™ and AMBE-3000™ Vocoder chips, are both DSTAR compatible. iCOM originally introduced the DSTAR system based on the AMBE-2020™ Vocoder chip that utilizes DVSI’s AMBE+ technology. Since that time, DVSI has developed and produced the AMBE-3000™ Vocoder chip that implements DVSI’s latest generation AMBE+2 technology and is fully interoperable with the the AMBE-2020™ vocoder chip used for DSTAR. The enhancements of AMBE+2™ technology in the AMBE-3000™ vocoder chip can provide superior voice quality in some circumstances. The highest level of voice quality can be achieved when the AMBE-3000™ Vocoder chip (or equivalent software2) is incorporated into the equipment used on both ends of the radio link.”

So the answer is a definite maybe.

1 The DV Dongle is manufactured by Internet Labs.
2 Current ICOM D-STAR products use a software vocoder that incorporates the 3000 advancements.

ThumbDV™: Budd Churchward, WB7FHC Video

Budd updates us on his experience setting up the ThumbDV™ under Windows using Node DV (WinDV) from DUTCH*Star.

Also, there is an updated setup guide from the folks at

ThumbDV™ vs PiDV™

We have received a few inquiries about the functional difference between the DV3000 and ThumbDV™.

The ThumbDV™ is a thumb or dongle type DV (digital voice) device for connection to a computer (PC, Laptop, Tablet, Raspberry Pi, Odroid, etc.) to provide access to AMBE encoding and decoding.  It is the more portable of the two devices in that you can plug it into any USB (2.0 or greater) port on a computer and access it as a serial port via appropriate software to get into the D-STAR system.

AMBE USB 3000 ThumbDV™


The PiDV™ is designed to use the GPIO UART pins on a Raspberry Pi (including Raspberry Pi 2 and compatible devices such as the Odroid C1)  to provide access to AMBE encoding and decoding.  It can be adapted to other similar devices using jumper wires to connect the UART, but only maps to Raspberry Pi GPIO pins.



From a software point of view they are equivalent and are accessed as serial ports (COMx under Windows,  tty? under Linux/Mac OS X, UDRx) at 230.4 kbps.  Software for using these devices includes G4KLX’s DummyRepeater,  DUTCH*Star’s Node DV (WinDV), and modified versions of DSD (developers have modified for use with the ThumbDV™/PiDV™ for monitoring DMR, Fusion, P25 Phase 2, etc. — contact the developers for more information).

Visit the resource page for additional information.


Email Updates

Hi all,

We’ve received a few support requests regarding order status.

An automated email is sent from when the order is accepted and another when it is shipped, complete with USPS tracking number. For International orders, USPS delivers to your countries postal service which may or may not provide tracking updates. We have no more visibility than you do.

If you don’t receive an email it’s due to one of the following:

  • The email in your order is incorrect or it’s an email you don’t check
  • It’s in your spam folder
  • Your ISP has blacklisted GoDaddy

We can’t do anything about the first two, but we’re checking on alternatives for the last one. By all means if you don’t receive confirmation, send an email to support and we’ll process it manually.

PiDV™ featured on Amateur Logic TV

AmateurLogic.TV highlights thePiDV™ (previously named DV3000) on the their videocast!  The segment starts at minute 51.

The referenced guide is at thanks to VE3MIC.

One update: The latest G4KLX DummyRepeater gives the option of using AMBEserverGPIO or accessing the DV3000 directly as a serial device and directly supports ALSA audio.

ThumbDV™: DUTCH*Star Support Under Development

Fred (PA4YBR) at DUTCH*Star has been working on support for the ThumbDV™ in his Node DV/WinDV program.

It is now in beta test and working well.  Watch for more information at