2pcs/lot DMR818 AMBE Digital mobile radio UHF | VHF 2W 6~8Km DMR wakie talkie transceiver
Precio habitual $138.29
DMR818 is a 2W long distance DMR walkie talkie module, it comes with built-in highperformance microcontroller, digital mobile radio IC and RF power amplifier. All parameters(CTCSS,CDCSS, SQ, Predefined channels etc.) can be easily modified with protocol. With external powersupply, speaker, and audio amplifier, it is easy to become a professional digital walkie talkie.Simplified interface and Ultra small size make this module widely used in various applications andconveniently embedded into various handheld device.
* Message transmission and reception.
* Message calling return receipt;
* Enhanced encryption of Voice and Text message.
* Various voice call types: All call, Group call and Private call;
* Reminder for input calling, calling status checking
* Emergency alarm and radio monitor;
* Radio kill and activate;
* Analog mode:
* CTCSS/CDCSS configurable
* Squelch levels configurable
* UHF band frequency: UHF 400-480MHz/ VHF 134-174MHz / UHF 320-400MHz for option
* Distance up to 6Km
* Max power output to 2W, low power to 0.5W
* High Sensitivity: -124dBm
* Bit error rate down to 1% under -121dBm
* Independent frequency for Tx and Rx.
* Bandwidth: 12.5 / 25 KHz
* DMR(Digital Mobile Radio)/Analog
* Message transmission and receiption
* Built-in EEPROM, data saved even powered off
* 1ppm TCXO crystal
* 51 CTCSS
DMR818 has default 16 channels, CH1~CH8 in DMR mode, CH9~CH16 in analog mode. All the parameters can be configured by serial instructions. For details, please check “DMR818 communication protocol”.
Note: When module in radio killed mode, most of the serial instructions can’t be responded, It will return message 0x07 (Radio killed) or 0x01(Busy) to indicate.
1) Voice transmission
“PTT” pin is used to control the voice transmission. Pull low to enable voice transmission; High to end transmission.
Note: Serial instructions can also be used to enable voice transmission and ending. For details, please check “DMR818 communication protocol”
2) Voice receiving
After power on, DMR818 will enter into receiving mode automatically. It will return back to receiving mode after voice transmission ended.
For details of receiving process, please check “DMR818 communication protocol”.
Message can be set as confirmation message and non-confirmation message before transmission. When the message is set as non-confirmation, the message can be rejected or accepted by the receiver. When the message is confirmation, it will be accepted by user.Pre-written message can be stored and used.
For details of messages, please check “DMR818 communication protocol”.
4) Switch of Audio amplifier
Pin “SPK_EN” is used to control external audio amplifier. When playing voice, SPK_EN in high level, low level when other status. The timing of SPK_EN as blow:
Antenna is an important part in communication system. Its performance will influence the whole communication system. This module requires antennas impedance in 50oHm. Regular used antenna is rubber straight antenna, sucker antenna, telescopic antenna and so on. Users can choose the antenna according to the application environment. To make sure modules in the best working mode, we recommend the antennas from our company.
- 2pcs UHF(400 - 470MHz ) Digital walkie talkie module DMR818-AMBE
or 2 pcs VHF(134~174MHz) or 350MHz(320~400MHz) frequency, just leave message please!