Adding 450 MHz transmissions to a Trimble 900 MHz base station

The TDL510 radio can be used to add an external 450 MHz radio to an existing Trimble 900 MHz base station that is transmitting corrections via an internal 900 MHz radio, for example, the Trimble R750 GNSS receiver (P/N CON-R750-900).

  1. Install the radio either in a protected enclosure for long-term use or on a tripod for daily setup.

  2. Connect an appropriate 900 MHz antenna to the RF connector on the top of the radio.

    • P/N 123588 is recommended for short-range usage. This is a dual-band antenna that can be used with the radio in either 450 MHz or 900 MHz mode.

    • P/N 56510-6x is the recommended external 5 dB antenna kit for maximum range:

      • P/N 56510-64 Kit - External UHF Antenna, 430 to 450 MHz, R750, MPS566

      • P/N 56510-66 Kit - External UHF Antenna, 450 to 470 MHz, R750, MPS566

     

    • UHF antennas should be mounted high with line-of-sight to the rovers and machines.

    • There should be a minimum of 2 m separation between the two transmitting antennas.

  3. Connect the SAE connector on cable P/N 128287 with an appropriate 12 V DC power supply.

  4. Connect the DB9 RS-232 serial connector on cable P/N 128287 to the COM2 serial output on the Trimble base station using the recommended cable:

    • R750 (COM2) P/N 78235-10 or P/N 57168-HH

  5. Enable a correction stream (suitable for the 450 MHz rovers and machines) at 1 Hz on COM 2 of the Trimble base station.

  6. To set bandwidth limiting, use the the I/O Configuration page of the base station web interface. You may require bandwidth limiting for corrections streams supporting all constellations:

    • CMRx

    • RTCM3 MSM3

    Region code

    US

     

    US

    Channel spacing

    12.5 kHz

    25 kHz

    OTA baud (bps)

    4800

    9600

    19200

    CMR+

    None

    None

    None

    RTCM 3 (legacy)

    None

    None

    None

    CMRx

    300 bytes/sec

    700 bytes/sec

    700 bytes/sec

    RTCM 3.3 (MSM3)

    300 bytes/sec

    700 bytes/sec

    700 bytes/sec

  7. Use the front panel and keypad of the radio to set the:

    • Channel – Select from preconfigured list of frequencies.

    • Compatibility/OTA protocol.

    • Transmit power – Default = 1 W Max.

    See the TDL510 Radio Quick Start Guide or End user settings.

    8.  

    • Ensure that the serial port settings are identical for the base station and the radio.

    • Check the LEDs on the front of the radio for operational status. See LED modes.