Narrow Band Low curent Receiver

The RX1L receiver modules have very low current consumption (1mA) and it offers a reliable data link in an industry-standard pin out and footprint. This makes the RX1L ideally suited to those low power applications where existing narrow band modules are not suitable for prolonged battery powered application. Two versions on the 151.300MHz and 173.225MHz frequencies are available. RX1L is compatible with the Radiometrix TX1 and BiM1T transmitters.


  • Conforms to EN 300 220-3 and EN 301 489-3.
  • Data rates up to 5 kbps for standard module
  • Fully screened. Low profile
  • Very low current consumption
  • Long battery life


  • Solar powered remote installation
  • Data loggers
  • Industrial telemetry and telecommand
  • In-building environmental monitoring and control
  • High-end security and fire alarms
  • Vehicle data up/download

Technical Summary

  • Size: 59 x 38 x 7mm
  • Operating frequency: 151.300MHz or 173.225MHz
  • Supply range: 3.1V - 9V
  • Current consumption: 1mA
  • Data bit rate: 5kbps max. (standard module)
  • Receiver sensitivity: -120dBm (for 12dB SINAD)

Evaluation Platform: Narrow Band Evaluation Kit
Matching Transmitters: TX1 , TX1H , HX1, BiM1T or BiM1HT

Figure 1: RX1L block diagram

Figure 2: RX1L footprint (Top) view

Pin Description - RX1L

Power: A
1 +Vin Supply input. 3.1V to 9V supply
2 0V Ground
1 Gnd RF ground
2 RF in To antenna
3 Gnd RF ground
User: C
1 no pins
2 no pins
3 AF out 200mV pk-pk audio. DC coupled, approx 1V bias
4 DATA out output of data slicer suitable for Biphase codes. 3V CMOS logic levels
5 +3V out/in DC supply. 10mA max. drain. Present if unit is powered
6 0V Ground
7-10 no pins

1. "+3V out/in" can be used to power the radio from an external regulated 3V supply.
2. While pin equivalent to the RX2M450, the RX1L lacks carrier detect, RSSI, modem or multi channel functions.

Condensed specifications

Frequency 151.300MHz or 173.225MHz (other frequencies on request)

Frequency stability

+/- 2.5kHz
Channel spacing
Number of channels
Supply voltage 3.1V - 9V (or 3V +/- 10% via 3V out pin)
Current 1mA
Operating temperature -10 to +60 °C (Storage -30 to +70 °C)
Size 59 x 38 x 7 mm
Spurious radiations Compliant with ETSI EN 300 220-3 and EN 301 489-3
Interface user 4pin 0.1" pitch molex
Power 2pin 0.1" pitch molex
RF 3pin 0.1" pitch molex
Recommended PCB hole size 1.2mm
Intended approval ETSI radio standard EN 300 220-3 and EMC standard EN 301 489-3
Sensitivity -120dBm for 12 dB SINAD
image / spurious -65dB
blocking -80dB
adjacent Channel <-70dB (Tested per. ETSI EN 301 489-3)
outputs audio, data
Power on to valid audio 20ms
Power on to stable data out (50:50 mark / space) 50


1. The data slicer cannot be depended upon for data waveform frequencies below 250Hz
2. When RX is on and a transmitter keys up, again a 50ms period is required to stabilise data output mark/space. i.e. allow at least 50ms of preamble

Limitation of liability

The information furnished by Radiometrix Ltd is believed to be accurate and reliable. Radiometrix Ltd reserves the right to make changes or improvements in the design, specification or manufacture of its subassembly products without notice. Radiometrix Ltd does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. This data sheet neither states nor implies warranty of any kind, including fitness for any particular application. These radio devices may be subject to radio interference and may not function as intended if interference is present. We do NOT recommend their use for life critical applications.
The Intrastat commodity code for all our modules is: 8542 6000.

R&TTE Directive

After 7 April 2001 the manufacturer can only place finished product on the market under the provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive may demonstrate compliance to the essential requirements specified in Article 3 of the Directive, as appropriate to the particular equipment.
Further details are available on The Office of Communications (Ofcom) web site:
Licensing policy manual