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The USB-Digimode-3-Micro-URI


This compact USB Audio interface will plug into a PC or Raspberry Pi running the HamVoip software so that you can build your own Allstar Node Link. The bespoke USB Sound card is built into the USB shell and uses the CM108B audio codec. It is not a modified cheap Chinese board from eBay.

Key Features

  • Built-in C-Media CM108B USB Audio codec. Fully supports as a USB audio device in HamVoip.
  • Levels set up. The interface is designed to deal with expected audio levels from radio data ports for Tx/Rx.
  • CM108B GPIO VOL DN supported for COS to connect to radio SQL line.
  • CM108B GPIO3 PTT supported by built-in buffer/driver.


    The C-Media CM108B codec is fully supported in HamVoip as a USB audio device. Tx and Rx audio levels are suitable for direct connection to modern transceiver data ports. The CM108B  "GPIO3" signal is used for PTT keying and the "VOL DN" input for COS (Carrier operated squelch). These particular GPIO signals are expected in the Hamvoip USB audio setup.


    For the PTT, set the Ham Voip simple-usb-tune-menu option "I" set to "active low".
    For  COS (Carrier operated Squelch)  setting the Ham Voip simple-usb-tune-menu option "J" to
    "usb" works on for example Yaesu Radios.

    Cable length from USB to connector is 10cm so perfect if you are installing inside a case with a Raspberry Pi.

    Radio Connection

    You can choose to have the interface shipped with a pre-wired DB9 Female, Standard wired 6 pin Mini-Din (Yaesu, Icom, Kenwood)  or we can provice it with tinned wire ready for you to add your own plug.


    Option 1 - DB9 Plug

    Pin 1 - Rx audio from the radio to the USB interface.
    Pin 2 - PTT signal. Pulls low for PTT keying. (Ham Voip simple-usb-tune-menu option "I" set to "active low")
    Pin 3 - COS Signal. Configuration depends on your radio. For Yaesu, COS set to "usb" works. Your radio may need "usbinvert"
    Pin 4 - Tx audio from interface to the radio.
    Pin 5 - Ground (0v)


    Option 2 - 6 Pin Mini-Din Plug

    Pin 1 - Tx audio to the radio

    Pin 2 - Ground

    Pin 3 - PTT

    Pin 4- Not Used

    Pin 5 - Rx Audio from the radio

    Pin 6 - Squelch line from the radio


    Option 3 - Bare wiring

    Black - Tx audio from interface to the radio
    Yellow - Rx audio from radio to the interface
    White - PTT signal.

    Red - COS signal
    Screen is ground/0v



    AllStar Link USB Sound Card Interface

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