Mobile | DMR


diagram indicating highlights of HM685


    Created with Sketch. Reliable Communication

    Thanks to the high RX sensitivity, the HM685 can deliver clear and dependable communications even in areas where the signal is unstable or weak.

    Created with Sketch. Digital and Analog Compatibility

    The HM685 can operate in either analog or digital mode, which is the ideal solution for you to migrate from analog to digital with minimal disruption and investment.

    Created with Sketch. Innovative Design

    Compact and lightweight, the HM685 is easy to install, remove, or operate in the vehicle. The front panel adopts two-shot molding to make the operation more recognizable. The transflective display is readable even in the dark or direct sunlight. At the bottom of the display, the four piano-style keys offer great haptic feedback when pressed.

    StayConnected-0x20 Wireless Connection

    With the built-in BT 5.0 module*, the HM685 can work with the BT audio accessories to boost your safety and productivity during in-vehicle communications. And these radios can be programmed through BT, saving time and resource.*Please be advised that this feature is only applicable to the BT HM685 version only

    Created with Sketch. Crystal-clear Audio

    The HM685 delivers superb audio in noisy streets or highways. The AI-based noise cancellation filters out echoes and background noises such as horn and engine sounds, making you hear and be heard in the conversation. The howling suppression prevents the screeching or howling feedback between two radios in the same vehicle, ensuring clear and uninterrupted communication on the move.

    MIL-STD-20x20 Superior Durability

    The HM685 withstands harsh temperatures, shock, and vibration, and meets MIL-STD-810G standards, and IP54 for dust and water intrusion. The connection between the palm microphone and the 10-pin aviation connector is very secure preventing it from becoming loose. The palm microphone cord has excellent stretching ability to protect it thus giving the maximum service life.

    Accessories for HM685

    Included as standard with HM685 Included as standard with HM685

    Related products that work with the HM685

    Technical Specifications


    Frequency Range
    Channel Capacity
    Zone Capacity
    Operating Voltage
    13.6V±15% DC
    Current Drain(Standby)
    Current Drain(transmit)
    Current Drain(receive)
    5W: <4A;25W:<8A; 45W:<12A
    Dimensions(H×W×D) mm
    164 x 159 x 42mm
    1.45 inch, 4Line


    Analogue: 0.18µV (12dB SINAD)
    Analogue: 0.16µV (12dB SINAD) (Typical)
    Digital: 0.18µV / BER 5%
    TIA-603: 65dB @12.5kHz / 75dB @20/25kHz
    ETSI: 50 dB @12.5kHz / 70dB @20/25kHz
    TIA-603: 75dB @12.5/20/25kHz
    ETSI: 70dB @12.5/20/25kHz
    Spurious Response Rejection
    TIA-603: 75dB @12.5/20/25kHz
    ETSI: 70dB @12.5/20/25kHz
    TIA-603: 90 dB
    ETSI: 84 dB
    Hum and Noise
    40dB @12.5kHz; 43dB @20kHz; 45dB @25kHz
    Related Audio Power Output
    internal (20 Ohm load): 3W
    external (8 Ohm load): 6W
    Max Audio Power Output
    internal (20 Ohm load): 7.5W
    external (8 Ohm load): 20W
    Rated Audio Distortion
    Audio Response
    +1 to -3 dB
    Conducted Spurious Emission
    < -57 dBm


    RF Power Output
    Low Power: 5-25 W
    High Power: 5-45 W
    FM Modulation
    11K0F3E @12.5kHz
    14K0F3E @20kHz
    16K0F3E @25kHz
    4FSK Digital Modulation
    12.5kHz data only: 7K60FXD
    12.5kHz data and voice: 7K60FXW
    Conducted/Radiated Emission
    -36dBm @<1GHz; 30dBm @>1GHz
    Modulation Limiting
    +2.5kHz @12.5kHz; +4.0kHz @20kHz; +5.0kHz @25kHz
    FM Hum and Noise
    40dB @12.5kHz; 43dB @20kHz; 45dB @25kHz
    Adjacent Channel Power
    60dB @12.5kHz; 70dB @20/25kHz
    Audio Response
    +1 to -3 dB
    Audio Distortion
    Digital Vocoder Type


    Operating Temperature
    -30℃ to +60℃
    Storage Temperature
    -40℃ to +85℃
    Dust & Water Protection


    TTFF (time to first fix) cold start
    < 1 minute
    TTFF (time to first fix) hot start
    < 10 seconds
    Horizontal accuracy
    < 5 meters