VHF Narrow Band FM Low Cost multi channel radio modules
LMT1/LMR1

The LMT1 transmitter and LMR1 receiver modules offer a multi channel, low power, and reliable VHF data link. This makes the LMT1/LMR1 pair ideally suited to those low power applications where existing wideband modules have insufficient range, or where low cost multi-channel operation is needed without compromising on RF specification or regulatory requirement.


Figure 1: LMR1-173-5 and LMT1-173-5

Features

  • Conforms to EN 300 220-3 and EN 301 489-3
  • High performance double superhet, PLL synthesizer with TCXO
  • quasi-dc (peak sampling) data recovery circuit (for enhanced performance on unbalanced datastreams)
  • Data rates up to 5 kbps for standard module
  • Usable range over 1km
  • Fully screened. Low profile
  • Feature-rich interface (RSSI, analogue and digital baseband)
  • Re-programmable via RS232 interface
  • Low power requirements

Applications

  • Handheld terminals
  • EPOS equipment, barcode scanners
  • Data loggers
  • Industrial telemetry and telecommand
  • In-building environmental monitoring and control
  • High-end security and fire alarms
  • DGPS systems
  • Vehicle data up/download
  • Heavy vehicle/machinery controls

Technical Summary

  • Operating frequency: 173.200 - 173.325MHz (UK band)
                                           150.825 - 152.450MHz (Australian Band)
  • Other VHF frequencies available·
  • 4 UK allocation channels (32 maximum)
  • 32 channels
  • Transmit power: +10dBm (10mW) nominal @ 3.1V (Adjustable 1 - 25mW)
  • Supply range: 3.1 - 15V (TX @ 10mW and RX), 4.1 - 15V (TX @ 100mW)
  • Current consumption: 34mA @ 10mW, 90mA @ 100mW (transmit) and 20mA (receive)
  • Data bit rate: 5kbps max. (standard module)
  • Receiver sensitivity -118dBm (for 12dB SINAD)
  • Serial configuration by inverted RS232 at 3V CMOS level
Evaluation Platform: Narrow Band Evaluation Kit