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FMR-05D
27MHz Radio Data Receiver
Features
• Long Distance
• Small Size
• Low power Consumption
• Fully screened metal housing
• Low Cost
Application
• Security Systems
• Radio Data Communications
• Telecommand Systems
• Commercial / industrial telemetry
• Alarms |
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 Download Datasheet
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Description
The FMR-05D radio data receiver is used for long distance digital data communications. The small size and low power consumption makes the FMR-05D most suitable for portable applications. The fully screened metal housing makes it less susceptible to interference. Together with its low cost it allows for this data receiver to be used in many diverse applications.
The FMR-05D receiver and the FMT-2712 can be combined to form a transceiver. This transceiver has a reliable operating range of up to 2100 metres in open field conditions and at speeds of 2400 bps.
The +5 V olts connection is the supply connection.
The Ground connection is used for the supply and shield connection if a coaxial cable is used with the antenna. Ground connection for shield connection is next to the antenna pin.
The Antenna connection is used for the antenna connection
The Data connection output is for the digital data received at 0 to 5 Volts.
The Signal Strength connection is a Relative Signal Strength Indicator. See below chart for output levels.
NB: Care should be taken that a data signal of 50% duty cycle is used. See notes on data format.
Compatibility
FMT-2712
Technical Data
Supply Voltage |
4.5-5.5Volts DC, absolute max 6.5Volts DC |
Current Consumption |
3.5mA |
Receiver Type |
Dual Conversion Superheterodyne |
Receiving Frequency |
27.145MHz (Other frequencies available: 27.045, 27.195 & 27.455MHz. NB. 27.455MHz is available for Europe Only) |
Type of Crystal Used |
10.245MHz, Fundamental, 20pF, 30ppm
16.495MHz, Fundamental, 20pF, 30ppm |
Operating Temperature Range |
-5 to +50°C |
Selectivity |
-6dB at ±5kHz, -20dB at ±6kHz |
Image Rejection |
At 26.285MHz better than -60dB |
Sensitivity |
-107dBm or 1uV |
Type of Demodulation |
Narrow-bandwidth Frequency Modulation (FM) |
Occupied Bandwidth |
±5.0kHz |
Freq Response |
20-1500Hz with 50% Duty Cycle (other duty cycles will degrade sensitivity) |
Data Output Level |
0-5V (see circuit for output impedance) |
Signal Strength Output |
4.42V at -100dBm (indicates a valid signal) |
Antenna |
Elsema’s ANT27MHz series antennas or piece of approximately 300 mm long wire for short range applications. |
Dimensions |
50 x 33 x 16mm |
Weight |
22g |
Data Format
It is important to have the correct data format otherwise the receiver will have a lower sensitivity. The 50/50 duty cycle data can be pulse-width modulated to transmit resets, 0's or 1's. See diagram below:
A 50/50-duty cycle will have an average DC signal resulting in a constant reference for the data slicer. Users should use pulse-width modulation to transmit data with logic 1's or 0's.
If a different duty cycle is used, for example 66/33 ( Manchester format) the data slicer in the receiver will try to adjust itself to the average DC signal. Since this average DC signal is changing with different data bits this will result in a constantly changing reference for the data slicer, resulting in lower sensitivity. See diagram below :
Only 50/50 duty cycle data is suitable for the FMR-05D receiver.
Circuit Diagram
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