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Datasheet: UDRCDS


These instructions apply to the BCR-220 repeater, but should also work with other Bridgecom Repeater models.

The BCR-220 with the UDRC™ opens the 220 band to D-STAR for the Kenwood TH-D74A and future 220 D-STAR radios.

Important: Use only Compass Linux images and dstarrepeater packages.  They contain support specific to the UDRC™. Source is available for review on GitHub.

During initial startup do not modify the basic Raspberry Pi setup. For example, do not overclock the Raspberry Pi, it is not needed as performance is more than adequate, and doing so can change clocking values on busses used by the UDRC™ causing it to either not function or be unstable.  If you make any changes not listed in these instructions, and your UDRC™ does not function, return to the original settings.

Mount your UDRC™ on a Raspberry Pi 2 or 3

Note: Raspberry Pi 3 Addendum

ARMv6 Raspberry Pis are not supported.  This includes the A/A+, Zero, Pi 1 B/B+, and Compute Module.

Make sure the pins are properly aligned and use the supplied standoffs to support the board above the HDMI port.

Universal Digital Radio Controller Universal Digital Radio Controller

ircDDB Registration

Now is a good time to register a unique callsign for your repeater at  In the United States this needs to be a club callsign, in other countries a secondary callsign is necessary.  If you want to use your personal call sign, you will be able to run the repeater and perform linking to repeaters and reflectors, but will be unable to do callsign routing including STARnet Digital groups. If you already have an ircddbgateway registered, you can just add this repeater to it via configuration.

Install Compass Linux


Apply change from:

Basic Configuration

  1. From a terminal command line, verify that the UDRC™ is recognized by typing the command
    aplay -l	
    (that's a lowercase l) and observe that udrc is listed as a card. If you do not see it listed, power down and remount the UDRC™.
  2. To preset the pins and levels on the UDRC™ we provide a script. Execute the following:
    cd ~
    curl -L -s >
    chmod +x
    sudo ~/

  3. Optionally disable the internal sound chip by editing /boot/config.txt and commenting out this line (recommended unless you need it for something else):
  4. cd /boot
    sudo nano config.txt
    # or
    sudo vi config.txt
    Then comment out the dtparam=audio=on line (near or at the bottom of the file) and add force_turbo.

Install Applications

You may install any mix of GUI and non-GUI versions of the repeater and gateway software. Use the following commands on the command line.

For the GUI tools:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install dstarrepeater ircddbgateway dstarrepeaterd ircddbgatewayd

We install the daemon versions as well because once you have everything configured you would typically run headless.

For the non-GUI tools:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install dstarrepeaterd ircddbgatewayd 

If you are running ircddbgateway on another computer, there is no need to install it on the Pi. You will configure dstarrepeater to access the ircddbgateway.

Prepare the BCR Repeater

The repeater will be configured to use CTCSS (or DCS) and set, on the front panel, to RPTR mode for Analog/D-STAR or BASE mode for D-STAR Only (No Analog).

Setup the Repeater Channel with your parameters -- be sure to select COS Settings as Valid Signal.  This tells dstarrepeater to block D-STAR transmissions from the network, or internally generated, when there is an analog transmission with a valid CTCSS or DCS tone being repeated, while in RPTR mode.

Also and un-check Transmitter PreEmphasis. D-STAR transmissions must not have PreEmphasis enabled.

Setup an analog slot with both RX and TX tones and optionally a courtesy beep.

The BCR mutes the TX signalling Tone/Code when IDing, so users will have to hit monitor to hear the analog ID.

Be sure to use CTCSS on RX/TX in analog, avoid 100.0 Hz as that can false on a GMSK signal.  

User radios should use CTCSS or DCS squelch on TX and RX.  Also, recommend to your users to activate BCLO (Busy Channel Lock Out) on their radios to help avoid stepping on transmissions in a different mode.

Cable for Connection of UDRC™ to Repeater

Connect the UDRC™ to the BCR-220 with a custom cable, see schematic.

A custom made cable (Model 203) can be fabricated by W7TUT.  Contact Information

Table of Connections

FunctionDB-25 Male ConnectorHD-15 Male Connector
+13.8VDC From Repeater115
Discriminator From Repeater88
CTCSS Detect Squelch From Repeater173
PTT To Repeater202
GMSK To Repeater Modulator216
Turn Off CTCSS/DCS Encoding To Repeater241
Ground255 (or 10)

Configuration of dstarrepeater

Download the seed file for the dstarrepeater

sudo curl -L -s -o /etc/opendv/dstarrepeater_1

If using the GUI install, you can edit the file with:

sudo -E dstarrepeaterconfig 1

If non-GUI, use an editor like nano or vi to edit, e.g.

sudo nano /etc/opendv/dstarrepeater_1

You will need to change the repeater callsign and gateway callsign to your system.  If you are doing a 1.25m repeater these are the only settings that need changed for initial configuration.  Only adjust other settings if you understand their effect.

The repeater will switch to D-STAR upon receiving D-STAR traffic and return to analog between D-STAR transmissions.

By Convention, unless you have an Icom 23cm digital voice repeater on the same gateway, use 'A' for the 220 D-STAR repeater module.

BandRepeater ModuleNotes
2 MetersCNorth American Convention
1.25 MetersANorth American Convention of 23cm band, use for 220 if no 23cm module on Gateway
70 CentimetersBNorth American Convention
Important: The repeater callsign and gateway callsign are always 8 characters. Use the station callsign, and then spaces to place the module letter in position 8.  Do the same for the gateway callsign with 'G' in the 8th position.
Starting dstarrepeater

Login to the Raspberry Pi and issue the command:

sudo systemctl start dstarrepeaterd@1

The repeater should now repeat D-STAR signals received on the repeater's input. Test by keying up and watching the D-STAR radio's display.

If you want to use the GUI, perform the following
sudo systemctl stop dstarrepeaterd@1
sudo dstarrepeater 1

Logs for troubleshooting are at /var/log/opendv

If you want the dstarrepeaterd daemon to start on reboot, issue the command:

sudo systemctl enable dstarrepeaterd@1

A video of hints for management of the daemon.


Since there are no special instructions for ircDDBGateway for the UDRC™, please refer to the documentation in the files section of the Yahoo Group ircDDBGateway If you would like a web based dashboard for ircDDBGateway, check out the real time dashboard at ircNodeDashboard

Visit our quick startup Wiki page for ircDDBGateway.


  1. Did you follow this Wiki exactly? Please review line by line.
  2. Make sure you didn't do anything to the Linux install, not listed in the Wiki (e.g. overclocking or other modifications)
  3. Are you using a Raspberry Pi 3 or 2? If a Raspberry Pi 3 -- review
  4. Does the repeater key up and repeat in FM mode? What PL are you using? Is PL set on both receive and transmit?
  5. Are you running dstarrepeater in GUI mode or daemon mode?  If GUI mode, make sure the daemon is not running in the background.
  6. Next see if the UDRC™ is receiving and decoding your transmissions. Open a terminal window and type:
    sudo tail -f /var/log/opendv/dstarrepeater_1.log
    (if in GUI, otherwise for the daemon run)
    sudo tail -f /var/log/opendv/dstarrepeaterd_1.log
  7. Key up on D-STAR, do you see header information coming from your transmissions?  If so, then receive should be good.
  8. Do you get a response from the repeater, with the end of transmission beep?  If yes, then your UDRC is functioning with the dstarrepeater program.  If no, then take a second radio and leave it open squelch on the output frequency of the repeater, transmit on D-STAR -- do you hear modem tones?  If so, switch the second FM radio to the input frequency of the repeater and transmit D-STAR, are the tones approximately the same "loudness"?  If not, then the setup is wrong from the alsa settings you loaded.


If you would like a web based dashboard for ircDDBGateway, check out the real time dashboard at  ircNodeDashboard