The Expanded Basic Stationary IR System is designed for applications where a variety of listening needs are necessary. This system includes both types of receiver, neckloop, headphone and the transmitter is rack mountable. Custom systems available. Radiator available in both grey or white.


One (1) LT-82 Stationary IR Transmitter
One (1) LA-326 Universal Rack Mounting Kit
One (1) LA-140 Stationary IR Radiator
Three (3) LR-42 IR Stethoscope 4-Channel Receiver
One (1) LR-44 IR Lanyard 4-Channel Receiver
One (1) LA-166 Neck Loop
One (1) LA-165 Stereo Headphones
Four (4) LA-363 High Capacity AAA Alkaline Batteries (2)
One (1) LA-304 Assistive Listening Notification Signage Kit


  • Accommodates up to four (4) listeners – great for applications to accommodate a small group
  • Outstanding coverage – 10,000 ft² (929 m²)
  • Secure wireless communication – ideal for applications where isolation of the signal is important
  • Up to four (4) channels mono or stereo – no need to sacrifice multiple channels to achieve stereo transmissions
  • Easy to specify, install and use
  • Outstanding performance ensures crystal clear sound for listeners
Configurations & Architectural Specs


LS-85-01-GY Expanded Basic Stationary IR System -Grey (North America)*
LS-85-02-GY Expanded Basic Stationary IR System -Grey (Asia, UK)*
LS-85-03-GY Expanded Basic Stationary IR System -Grey (Euro)*
LS-85-04-GY Expanded Basic Stationary IR System -Grey (Australia)*
LS-85-01-WH Expanded Basic Stationary IR System -White (North America)*
LS-85-02-WH Expanded Basic Stationary IR System -White (Asia, UK)*
LS-85-03-WH Expanded Basic Stationary IR System -White (Euro)*
LS-85-04-WH Expanded Basic Stationary IR System -White (Australia)*

*01, 02, 03, and 04 designation refers to international plug type (type B, G, C, and I) for the power supply. 

Architectural Specs

The LS-85 Expanded Basic Stationary IR System shall use infrared (IR) light to transmit audio from IR emitting radiators to portable IR receivers. The system shall use IR modulating frequencies above 2.0 MHz. The system transmitter shall have a timer that shuts off the carriers after 30 minutes when no audio is present at the transmitter. Channel selection shall be capable of being locked. The system shall be capable of transmitting on four (4) carriers and each of the four (4) carriers shall be capable of transmitting a mono or stereo signal. The system shall have a frequency response of 100 to 15 KHz (+/-3 dB), less than 2% distortion and shall have signal to ratio of greater than 60 dB. A single emitting radiator shall have a transmitting area of no less than 10,000 ft² (929 m²) (one carrier) or greater for each radiator specified. The radiator shall be powered via CAT-5 cabling and the RF from the transmitter shall be carried by 50 ohm coaxial cable. The LS-85 is specified.

Product Specifications
Specification LS-85-01-GY


Shipping Weight 20.0 lbs. (9.0 kg)
Q How long will the NiMH batteries last until they need to be recharged?
A You should receive 15 hours of use from each charge of the batteries.
Q Can the LT-82 be operated on 230 VAC?
A Yes, the LT-82 has a universal power supply that can be used anywhere in the world.
Q Is there any performance degradation in stereo mode?
A Yes, stereo operation raises the noise floor slightly.
Q Can I operate some channels in mono and others in stereo?
A Yes.
Q How do you replace the batteries in the receiver?
A 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.
Q How do I recharge the NiMH batteries?
A Use the Listen LA-350 8-Unit Charging/Storage unit. This unit will charge batteries that are in receivers or out of receivers.
Q How many carriers does the LT-82 Stationary IR Transmitter produce?
A One.
Q How many carriers can be produced simultaneously in a room?
A Four. You will need one LT-82 Stationary IR Transmitter per carrier.
Q How are radiators connected to the LT-82?
A The carrier (signal) is connected using coax cable; power is connected using standard CAT-5 cabling.
Q How is power delivered to the radiator?
A Power is delivered with CAT-5 cables (connected between the radiator and either the LT-82 transmitter or the LA-205 power supply).
Q How many radiators can be powered from the LT-82 or LA-205 power supply?
A Two.
Q How much coverage is provided with the LA-140 radiator?
A 40,000 ft² (3716 m²) single channel with LR-4200-IR/LR-5200-IR receivers or 10,000 ft² (929 m²) single channel with LR-42/LR-44 receivers
Q Does the number of carriers affect the coverage?
A Yes, for two sources (carriers), the total coverage is half. For four carriers, the coverage per carrier is one-fourth.
Q What is the purpose of the delay compensation switch?
A This switch allows you to set up delay timing in a multi-radiator system so that each radiator receives the carrier at exactly the same time. This prevents signal dropouts that can be caused by out-of-phase signals (multi-path). With Listen’s delay compensation switch, it is not necessary to cut all of your coaxial cables to the same length - your shorter runs can use shorter cables, keeping your installation clean (and cost-effective).
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