IR Stethoscope 4-Channel Receiver
LR-42

Highlights

  • Secure wireless communication – ideal for applications where isolation of the signal is important or where security is a concern
  • Stylish, all-in-one unit stetho design – no wires to tangle for easy distribution
  • Receives up to four (4) channels mono or stereo – provides outstanding performance with crystal clear sound
  • Uses standard AAA batteries (available anywhere) or rechargeable Listen NiMH battery pack – gives you ultimate flexibility in managing battery life
  • Auto shut-off feature (after 30 minutes of no carrier) - saves battery life
  • Ear tips can be easily cleaned or replaced

Overview

The LR-42 stethoscope receiver is a very easy to use, comfortable and user friendly. This all-in-one receiver can receive up to four (4) channels in mono or stereo. It uses standard AAA alkaline batteries for more than 30 hours of use, or a NiMH rechargeable battery pack that delivers 15 hours of use per charge. The unit features auto shut-off after 30 minutes of no audio carrier, further extending battery life. The LR-42 boasts high performance audio specs in a small package and is compatible with other manufacturers’ products. The LR-42 is used for government compliance (such as ADA), assistive listening, language interpretation, live theatre, houses of worship, courtrooms, secure rooms and auditory description.

Includes

LR-42 IR Stethoscope 4-Channel Receiver
LA-152 IR Receiver Battery Compartment (Non-Charging)
Quick Reference Card

Architectural Specs

The stethoscope IR receiver shall be capable of receiving on four (4) carriers (2.3, 2.8, 3.3, 3.8 MHz) and the channel shall be displayed on one (1) of four (4) front panel LEDs. The receiver shall be capable of being locked on a channel. The receiver shall be capable of receiving a stereo signal on each of the four carriers. The receiver shall have a SNR of 60 db or greater and have built in squelch control. The device shall have an audio frequency response of 63 Hz to 15 kHz, +/- 3db and shall have distortion of less than 2%. The device shall operate for 30 hours with two (2) AAA alkaline batteries and 15 hours with two (2) AAA NiMH rechargeable batteries. The receiver shall be covered by a limited lifetime warranty. The LR-42 is specified.

CAD Drawing

    • Specifications

     SpecificationsLR-42
    RFCarrier Frequencies2.3 MHz, 2.8 MHz, 3.3 MHz, 3.8 MHz
    Number of ChannelsFour (4) selectable channels
    IR DetectorsTwo (2) detectors under front IR lens
    SensitivityOne (1) nW/cm2 at 40 db SNR
    Frequency Accuracy+/- .005% stability 0 to 50C
    SquelchAutomatic on loss of RF signal (40 db SNR)
    ComplianceFCC Part 15, Industry Canada, CE, RoHS
       
    AudioSystem Frequency Response63Hz - 15kHz (+/- 3dB)
    System Signal to Noise Ratio        (A-weighted)Mono: >60dB
     Stereo: >52dB
    System Distortion<2% total harmonic distortion (THD)
    Audio Output JacksNone. Built in Stethoscope speakers
    Audio Output Power20 mW maximum at 32 ohms
       
    ControlsUser ControlsVolume, Power, Channel Select
    ProgrammingChannel Lock, Auto Seek, Channel Lock-Out, Squelch
       
    IndicatorsUnit PowerIndicated by current channel selection LED
    Channel SelectionRed LED illuminates on the current channel selection
       
    PowerBattery TypeTwo (2) AAA alkaline batteries or NiMH battery pack
    Battery Life30 hours alkaline, 15 hours NiMH rechargeable pack (LA-364)
    Battery ChargingUp to 9 hours, fully Automatic with NiMH battery pack and LA-350 charger
       
    PhysicalDimensions (H x W x D)1.80 x 4.00 x 0.75 in. (46 x 102 x 19 mm)
    Stethoscope Arm length 8 in. (203 mm)
    ColorDark Grey with White Silk Screening
    Unit Weight without batteries2.15 ounces (60 grams)
    Unit Weight with batteries2.95 ounces (85 grams)
    Shipping Weight1.0 lbs. (453 grams)
       
    EnvironmentalTemperature - Operation14 ˚F (-10 ˚C) to 104 ˚F (+40 ˚C)
    Temperature - Storage-4 ˚F (-20 ˚C) to (122 ˚F)
    Humidity0 to 95% relative humidity, non-condensing
       
    ** All system specifications are wireless end to end**

    Requirements

    Used With

    • LT-82 Stationary IR Transmitter

      The Listen LT-82 is the heart of a stationary IR listening system. It takes the desired audio signal and transmits the signal via coaxial cable to one (1) or more IR radiator-emitters (LA-140).

    • LA-140 Stationary IR Radiator

      The IR radiator/emitter packs high infrared power in a small and attractive design, with your choice of grey or white packaging.

    Accessories

    Support Documents

    • FAQ

    How many receivers can be used in a system?
    Infinite number - there is no limit.
     
    How do you replace the batteries in the receiver?
    For non-rechargeable batteries (AAA alkaline), remove the battery compartment and replace the batteries with fresh AAA alkaline batteries. For rechargeable NiMH batteries, simply replace the sealed battery pack with a freshly charged pack.
     
    How do I recharge the NiMH batteries?
    Use the Listen LA-350 8-Unit Charging/Storage unit.This charging unit will charge batteries that are in the receivers, or batteries that are in our NiMH Rechargeable Battery Pack.
     
    How does the receiver know if the signal is mono or stereo?
    It automatically detects the type of signal and responds accordingly.
     
    My stereo signals are a bit noisy. How can I resolve this problem?
    Add more radiators. When you are transmitting stereo signals, the signal is degraded slightly. Increasing your radiator coverage will help mitigate this.
     
    What happens when there is no signal from the radiators?
    The receiver’s audio signal is muted and after 30 minutes the unit automatically shuts down to conserve battery life.
     
    How does the user select carriers?
    By pressing the SELECT button on the front of the receiver.
     
    Can the receiver automatically find a carrier?
    Yes, it will automatically seek and find all available carriers when the power is turned on. If no carrier is found, the unit will stop on the last used channel.
     
    Can I use a mono or stereo headphone with the LR-44?
    Yes.
     
    What is the warranty of the LR-42?
    All core products have a limited lifetime warranty.