Listen Technologies Portable FM 863 MHz, 863.050, 863.400, 863.5, 863.200 Design Manual

Dear Valued Customer,
Thank you for choosing Listen! All of us at Listen are dedicated to providing

you with the highest quality products available. We take great pride in their
outstanding performance because we care that you are completely
satisfi ed. That’s why we independently certify them to the highest quality
standards and back them with a limited lifetime guarantee. We stand ready
to answer any questions you might have during installation or in the operation
of our products. Should you experience any problems whatsoever with your
Listen products, we are ready to help you in any way we can with prompt,
effi cient customer care. Because at Listen, it’s all about you! And should you
have any comments on how we might improve our products or our
service, we’re here to listen.

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+1.801.233.8992
+1.800.330.0891 North America
+ 1.801.233.8995 Fax
[e-mail]
www.listentech.com

Listen Technologies GmbH
Jasminstr. 16
905 22 Oberasbach, Germany
[phone]
[phone]

Tel

Fax

www.listentech.de
[e-mail]

Thank you and enjoy your listening experience!
Best regards,

Russell Gentner and the Listen Team

Lifetime Warranty – the best in the business!

Listen’s full-time technical support is passionate about what they do and you can depend
on them to solve any equipment issues with confi dence. In the few instances where repairs
were needed, 99% of all clients indicated that they were happy with repair
turn-around-times and 85% of the time, clients were without their product for
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Assistive Listening • Language Interpretation • Soundfi eld • Tour Group • Conferencing

Portable FM Table of Contents

Design Guide
FM Technology Overview 5
System Overview 6
Key Concepts in Designing an FM System 8
Notes 10

LT-700-863 Portable FM Transmitter
Specifi cations 17
Block Diagram 18
Quick Reference 19
Setup Instructions 20
Operating Instructions 23
Programming Instructions 25
Accessories 28
Notes 29

LR-400/500-863 FM Receivers
Specifi cations 37
Block Diagram 39
Quick Reference 40
Setup Instructions 42
Operating Instructions 45
Programming Instructions (LR-500 only) 51
Accessories 52
Notes 53

Design Guide

LT-700

Supplementary Information
Frequency Chart 61
Battery Charging Information 62
Troubleshooting 63
Frequently Asked Questions 65
Compliance, Warranty and Contact Information 67
Notes 68

LR-400/500

Supplementary

Portable FM Design Guide Table of Contents

FM Technology Overview 5
System Overview 6
Key Concepts in Designing an FM System 8
Notes 10

Design Guide

3

Frequency Modulation (FM) Technology Overview

Frequency modulation (FM) is a means of transmitting audio using electromagnetic waves.
This same technology is used by local FM radio stations to broadcast voice and music. FM signals can travel
through most barriers – walls, fl oors, and ceilings. The distance a signal travels has many different variables
such as Radio Frequency (RF) output power, the type and placement of the antenna and the broadcasted
frequency. This section of the manual will help you design a system that will get the best range with the least
amount of interference.

Microphone

Design Guide

FM Transmitter

When designing an FM system it is important to keep the following in mind:

Receiver

• Multipath

Multipath interference is a form of RF interference that occurs when radio signals have more than one path
between the receiver and the transmitter causing the two RF signals to add out of phase. This could occur in areas

with RF-refl ective surfaces, such as furniture, walls, or fl oors. The result of multipath is the receiver audio coming in
and out of squelch when the receiver is moved. Portable applications are much more susceptible to multipath
than those that are stationary. Multipath distortion is often worse as the distance between transmitter and receiver
increases (RF power decreases). Multipath can decrease the audio quality of the transmission (refer to page 9 for

strategies on eliminating multipath).

• Antenna Positioning

For full RF functionality of the portable system, the antenna on both the LT-700 transmitter and receiver (LR-400/500)

must be in the upright position (shown below).

5

System Overview

Design Guide

Behind-the-Head Microphone

There are three main parts to a Portable FM System – Input source, transmitter, and receiver.

LA-278

(other microphones available)

LT-700-863

Portable Display FM

Transmitter (863 MHz)

LR-400-863

Portable Display FM

Receiver (863 MHz)

LR-500-863

Portable Programmable

Display FM Receiver (863 MHz)

Input Source

A microphone is the most common input source for the LT-700 transmitter, although, the LT-700 can transmit
two audio inputs at once on one transmission channel. With the use of the LA-263 both the inputs will be mixed.
Thus, a person can use a line input source and mic source.

Mic input

3.5mm Phone Wiring

Unbalanced

+ Tip

- Sleeve

+ Ring

Line input

-

6

System Overview

Transmitter

The LT-700 modulates the audio on an FM carrier and transmits the signal via an anten­na on the unit.

Design Guide

LT-700-863

Portable Display FM

Transmitter (863 MHz)

Receivers

Listen offers two different portable receivers.

LR-400-863

Portable Display FM

Receiver (863 MHz)

LR-500-863

Portable Programmable

Display FM Receiver (863 MHz)

7

Key concepts in designing a portable FM system

Channel Selection

Design Guide

Use this section of the guide to choose the channel settings for the transmitter and receivers.

• The goal is to fi nd a transmission channel(s) that is free from interference. Interference originates from
other transmitters and from other equipment (such as a computer).

• Listen products offer 17 different channels to choose from. This increases the chance you’ll fi nd an

interference free channel.

• The best way to check for interference is to use the “SEEK” button on the receiver. Be sure all Listen

transmitters have been turned off if there is interference, the receiver will fi nd these channels.
If the receiver fi nds a frequency in use, do not use this channel.

• In general, most of the channels will be free from interference.

• Interference can be overcome by maximizing the transmission power and by using the receivers close to
the transmitting antenna.

• If more than one channel is in use, space the channels further from each other. Use the Listen frequency
chart on page 61 to determine the appropriate channels.

EXAMPLE: 2 channel system use channels 01 & 11
3 channel system use channels 01, 06 & 11

Range

The range of a portable transmission will vary from one application to another. There are many different
obstructions that could minimize the range. In most applications, the range will be approximately as shown
below (P= Power Level - refer to page 26 for programming power levels of the LT-700).

P1 – 30 meters (100 ft)
P2 – 46 meters (150 ft)
P3 – 61 meters (200 ft)

Range varies depending on environment.

Maximizing Range
Here are some tips to maximize the transmission range:

• Eliminate or minimize obstructions between the transmitter and receivers.

• Minimize the distance between the transmitter and receivers.

• Move transmitter and receivers away from metal objects.

• Orient both transmitting and receiving antennas vertically.

8

Key concepts in designing a portable FM system

Eliminating Multipath

As mentioned on page 5, multipath can occur with portable RF systems. The audio quality of the
transmission can decrease with the occurrence of multipath. Here are a few potential improvements that
can help if multipath takes place:

Squelch

Squelching the receiver will mute the audio output when the signal from the transmitter is turned off or
the signal is too weak to be received. Without squelch you would hear radio noise in your earphone with
no RF signal present. “Tightening” the squelch will turn the receiver off if it is chattering because of
multipath (refer to page 48 for programming squelch). Keep in mind, “tightening” squelch will limit the
range between transmitter and Receiver.

Transmitter power level

The RF power level can be adjusted on the LT-700 (refer to page 26 for programming LT-700 power levels).
The lower the power setting, the less range the transmitter will broadcast. Decreasing the broadcast range
will force the receivers to remain closer to the transmitter. To maintain an RF signal, the higher power
settings will increase range between transmitter and receiver thus introducing a higher probability of
multipath.

Multiple Portable Systems

In some applications, there will be more than one RF transmission in the same general vicinity.
Intermodulation interference can occur if the transmission frequencies are too close together. Here are
some ways to eliminate the chance of RF interference:

Design Guide

Squelch

Much like a multipath situation, “tightening” the squelch on the receiver will mute the audio output when
the signal is too weak to be received. Tightening the squelch will help with force the receiver to squelch
when signal becomes too weak. (refer to page 48 for programming squelch).

Transmitter power level

As mentioned above, the RF power level can be adjusted on the LT-700 (refer to page 26 for programming
LT-700 power levels). The lower the power setting, the less range the transmitter will broadcast. Lowering the
power could help decrease the amount of interference if there are many frequencies being used in the
vicinity.

Spacing of channels

Use a Listen frequency chart (on page 61) to determine the channels frequency and space the number of
channels further from each other.

DX/Local

The receiver can be adjusted to receive only the strongest signals (refer to page 50 for DX/Local
information). A DX signal will be less sensitive because distance is the ultimate goal. For applications where
you want to minimize the distance, local mode will only search for strong signals. Local mode is much
more sensitive than DX.

9

Notes

Design Guide

10

Notes

Design Guide

11

800

LT-700 User’s Manual Table of Contents

Specifi cations 17
Block Diagram 18
Quick Reference 19
Setup Instructions 20
Operating Instructions 23
Programming Instructions 25
Accessories 28
Notes 29

LT-700 Package Contents

• LT-700-863

• Quick Reference Card

• Warranty Card

• FM Manual Card

LT-800LT-

LT-700

Listen Confi gurations

• LT-700-863

LT-700-863

Portable Display FM

Transmitter (863 MHz)

15

800

LT-700-863 Specifi cations

Architectural Specifi cation

The LT-700-863 portable FM Transmitter shall be capable of broadcasting on 17 channels. Channel tuning shall be capable of being
locked. The transmitter shall have a SNR of 70 db or greater. The output power shall be adjustable to quarter, half or full. The device
shall have an audio frequency response of 50 Hz to 15 kHz, +/-3 dB. The device shall incorporate a microphone sensitivity switch.
The device shall incorporate a mute switch. The unit shall utilize two 2 AA batteries. The battery door shall be capable of being
mechanically locked. The device shall incorporate an LCD display that indicates battery level, channel, channel lock, low battery,
battery charging, programming, and RF signal strength. The portable transmitter shall incorporate automatic battery charging
circuitry for recharging of NiMH batteries. The Listen LT-700-863 is specifi ed.

Specifi cations LT-700-863

RF Frequency Range 863.050 - 864.950 MHz
Number of Channels 17 wide band
Frequency Accuracy ± .005% stability 32 to 122º (0 to 50º C)
Transmitter Stability 50 PPM

RF

Transmission Range 0 ft. (0 m) to 200 ft. (60.9 m)
Output Power 10 mW maximum (adjustable)
Antenna Uses microphone cable
Antenna Connector 3.5 mm connector
Compliance CE, ETSI, RoHS

LT-800LT-

LT-700

Audio

Controls

Indicators

Power

Physical

System Frequency
Response

System Signal to Noise
Ratio

System Distortion <2% total harmonic distortion (THD) at 80% deviation
Microphone Input
Microphone Sensitivity Three position switch: high, middle, and low; 6 dB increments
Line Input
Microphone Power 3 VDC Bias

User Controls Power, mute, channel UP/DOWN
Set-up Controls (battery

compartment)
Programming Channel Lock out, Channel lock

LED

Display

Battery Type Two AA batteries, alkaline or NiMH
Battery Life

(Listen batteries)
Battery Charging

(NiMH only)

Dimensions (H x W x D) 3.00 x 1.00 x 5.00 in. (7.6 x 2.5 x 13.0 cm)
Color Dark Grey with white silk screening
Unit Weight 3.9 oz (111 g)
Unit Weight with batteries 5.8 oz (164 g)
Shipping Weight 1.0 lbs. (0.45 kg)

Door

50 Hz - 15 kHz (± 3 dB)

70 dB (A-Weighted)

Unbalanced, tip of 3.5mm connector, -20 dBu nominal, -30 dBu
maximum, impedance 21 ohms

Unbalanced, ring of 3.5mm connector, -10 dBu nominal input
level, -3 dBu maximum, impedance 10K ohms

Mic sensitivity, NiMH/alkaline battery, SQ enable/disable

Red, illuminated when unit is on. Flashes when batteries are
low, or to indicate charging. Flashes when muted

Channel Designation, lock status, signal strength indication,
battery life, RF Power

15 hours alkaline (LA-361), 8 hours NiMH rechargeable (LA-

362)
Fully automatic, 13 hours

Manually Lockable. Up, down, and power buttons through
door. Other controls behind door (see controls)

Environmental

Temperature - Operation 14 to 104º F (-10 to 40º C)
Temperature - Storage -4 to 122° F (-20 to 50° C)
Humidity 0 to 95% relative humidity, non-condensing

Specifi cations are subject to change without notifi cation

17

00

LT-700 Block Diagram

LT-800

LT-700

115/230VAC

50/60 Hz

LCD Display

Universal

Power Supply

(not included)

ANTENNA

7.5 VDC

Power Supply

CPU Module

Alkaline

(2) AA Batteries

ALkaline or NiMH

NiMH

Pre-emphasisRF Modulation

3 VDC

Companding

Q-Technology

Up

Down

Power

Power charge indicator

Red LED

Mic

Tip

Sleeve

Line

Ring

18

800

LT-700 Quick Reference

Articulating Flexible Antenna

Power/Charging Port

3.5mm Input Jack: Connect a Listen microphone here.
LED: When lit, indicates unit has power,

when fl ashing unit is muted/charging.

Mute On/Off switch

Look&Listen™ Display: Shows
transmit level, channel,
programming, battery status, and
lock status.

Power Button: Turns
power On/Off.

LT-800LT-

LT-700

Front Door Lock

Channel Select Buttons

Channel Display: Displays the
channel the LT-700 is currently on

RF Output
Indicator: Indicates
the RF transmit
level.

Battery Select Switch: Choose
the type of batteries being
use

d.

Battery Compartment: Place
2-AA batteries in compartment.
Be sure to follow polarity
pattern.

.

Battery Level Indicator

Program:
function is in
process.

L/O: Indicates while in
programming mode the specifi c
channel has been locked out.

Lock Icon: Indicates the unit is
locked on current channel.

19

LT-800

00

LT-700

LT-700 Setup Instructions

1

Unpack the Product

Remove outer packaging and plastic cover. Inspect for physical damage. If damage is apparent, please
contact the dealer from which the product was purchased or Listen Technologies
Corporation technical support for assistance (refer to page 67 for contact information).

2

Open the front access door

If locked, use a pocketknife or small screwdriver to unlock the door locks on both sides of the unit.
To unlock the door, rotate the lock ¼ turn counterclockwise. Grip the two tabs with your thumb and index
fi nger and pull the door downward. DO NOT place batteries in the unit at this time.

3

Select Battery Type

Two types of batteries may be used: NiMH or Alkaline. The unit is shipped with the switch in the Alkaline
position. Use a pen or small screwdriver to select the battery type.

WARNING: Do not place the BATTERY switch in the NiMH position if you are not using Nickel Metal Hydride

CAUTION: If you are using any battery type other than rechargeable Nickel Metal Hydride (NiMH)
batteries, make sure the BATTERY selection switch is in the alkaline position.

Batteries. The NiMH position will attempt to charge any batteries in the unit, even if they are
not the proper type. Charging non-Nickel Metal Hydride (NiMH) batteries will result in physical
harm, destruction of property and/or fi re.

20

Battery select switch

800

LT-700 Setup Instructions

Set Mic Sensitivity Switch

4

The microphone sensitivity switch is located inside the battery compartment, to the left of the
BATTERY selection switch. The LT-700 is shipped with this switch in the center (MED) position. Listen
recommends the following settings for our microphones. If you are using a microphone from
another vendor, you may need to experiment with different settings.

Part # Description Setting

LA-261 Lavalier Microphone MED
LA-262 Over-the-Head Microphone MED
LA-272 Over-the-Head Microphone w/Earphone MED
LA-274 Hand Held Microphone HI
LA-276 Collar Microphone HI
LA-277 Behind-the-Head Microphone MED
LA-278 Conference Microphone MED

NOTE: If the setting is too low for the microphone in use the audio will be faint. If the setting is too high
for the microphone in use the audio will be distorted.

LT-800LT-

LT-700

5

Place Batteries in Unit

Place two AA batteries in the compartment, making note of the battery polarity shown in the
battery compartment, and again verifying that the BATTERY SELECT switch is in the correct position
for the batteries you are using. (Alkaline should be selected for all battery types other than NiMH).

+

+

-

-

+

+

-

-

21

LT-800

00

LT-700

LT-700 Setup Instructions

6

Connect the Microphone

The microphone jack is located on top of the unit.

7

Connect the Line Input Cable (Optional)

This cable allows you to connect a TV, CD player or other equipment to the LT-700. To do this, you must
order the Listen LA-263 Line Input Cable (not included with your unit). This cable allows you to connect
both a microphone and line input to the jack on top of the LT-700. See the diagram below for connection
information. You can use the microphone and the line input at the same time.

NOTE: The MUTE switch mutes only the microphone; the line source will continue transmitting when the

switch is in the MUTE position.

22

800

LT-700 Operating Instructions

e

.

fu

g

p

gu

i

)

f

gu

i

e

P

1

Turn Unit On

1A

Power On/O Button

When you press the power button, the unit turns on. The LED on top of the unit will be
illuminated and the LCD display will be visible.

Antenna Positioning

2

Raise the antenna to the upright position. When the antenna if fully upright, it will click
into position.

upright position. When the antenna if

NOTE: Be aware that the transmission range could decrease if the antenna is

not in an upright position.

3

Select the channel for transmitting

863 MHz operates on 17 wide band channels. Channels are displayed numerically (i.e. 01-17)
(refer to Channel Selection in design guide page 8) for guidelines on choosing an
interference free channel.

transmission range could decrease if th

osition

ransmittin

wide band channels. Channels are dis

tion in design

de page 8

or

delin

LT-800LT-

LT-700

23

00

LT-700 Operating Instructions

7

Using the MUTE / TALK switch

Slide the switch to the mute position and the microphone audio is muted. When the
microphone audio is muted, the LED on top of the unit fl ashes rapidly. Slide the switch back to the talk
position and the microphone audio will return to the transmission. If you are using the line level input, it will
not be affected by the mute/talk switch.

LT-800

LT-700

Locking the Transmitter on One Channel

The unit can be electronically locked on one channel so that it will not change channels even if the channel select
buttons are pressed. It is recommended to lock the transmitter on a channel that is being used in a single channel system
or when multiple systems are in the same area.

1

To lock on a channel

1A

Press and hold the DOWN button for 5 seconds

Press and hold the DOWN button for 5 seconds to lock the transmitter onto the desired
channel. Press and hold the button again to unlock.

NOTE: On the LT-700, when the channel is locked, a lock icon will appear underneath
“Listen” on the display.

24

800

LT-700 Programming Instructions

Program Mode Overview

The LT-700 can be programmed to transmit on a limited number of channels. For applications where users are
required to select a channel (such as classrooms or language interpretation application), and you don’t want
them to have to scroll through all of the available channels, this feature is ideal. The LT-700 can also be changed
from high to low power levels. Adjusting the power settings allows you to set the range of the transmission.

Entering Program Mode

While the unit is ON, press and hold the channel down and up buttons simultaneously for 3 seconds.

1

LT-800LT-

LT-700

The “PGM” icon on the LCD will appear indicating program mode is entered.

2

25

LT-800

00

W

W

LT-700

LT-700 Programming Instructions

Once in the program mode, a function menu is displayed. Function 1 (F1) is displayed as default. Pressing the

3

channel up or down buttons will scroll through the functions. Pressing the power button will enter that function.

F1- Channel Lock out. No channels are locked out as default. Pressing the up and down buttons will scroll through
channels. Pressing the power button will toggle between lock/lockout for that channel. When a channel is
locked out, the L/O on the LCD shall be displayed.

F2- Transmitter Power. High transmit power (P3) is the default. Pressing the channel up button will toggle
through the following settings:
a. Low power: LCD displays “P1”
b. Med power: LCD displays “P2”
c. High power: LCD displays “P3”

When no button is pressed for 10 seconds, the program menu is exited altogether, regardless of whether a

4

function is entered or not. To exit out of the program menu or function manually:

When in the programming menu: Press and hold power for 2 seconds. This exits the program mode.

4A

When in a programming function: Press and hold power for 2 seconds. This exits the function and goes back to

4B

the programming menu.

4C

Pressing and holding power for a full 4 seconds will exit both programming function and programming menu.

26

800

LT-700 Programming Instructions

A

Resetting to defaults

To reset the transmitter to default settings, follow these instructions:

3

Reset to default settings

Press and hold the Up and Down channel buttons while turning the unit on.

4A

Press and hold the Up and Down channel buttons while turning the unit on. This will light
up all segments of the display.

4B

After the transmitter has been reset

After the transmitter has been reset, the display will return with defaults present.

NOTE: The defaults are

• Power Level: P3

• Channel: 01
* Channel lockout: All channels active

LT-800LT-

LT-700

27

00

Accessories for LT-700

Accessories

LT-800

LT-700

LA-261

Lavalier Microphone

LA-274

Hand Held Microphone

LA-278

Behind-the-Head

Microphone

LA-262

Over-the-Head Microphone

LA-276

Collar Microphone

LA-304

Assistive Listening

Notifi cation Signage Kit

LA-272

e

Over-the-Head Microphone

w/Earphone

LA-277

Conference Microphone

LA-361

High Capacity AA Alkaline

Batteries (2)

LA-311 16-Unit Portable Charging/Carrying Case
LA-313 16-Unit Portable Carrying Case
LA-317 4-Unit Portable Charging/Carrying Case
LA-318 4-Unit Portable Carrying Case
LA-320 Confi gurable Carrying Case
LA-321 8-Unit Portable Charging/Carrying Case
LA-322 8-Unit Portable Carrying Case
LA-323 4-Unit Portable Charging/Carrying Case w/Removable Lid
LA-324 8-Unit Portable Charging/Carrying Case w/Removable Lid
LA-325 16-Unit Portable Charging/Carrying Case w/Removable Lid

28

LA-362

Rechargeable AA NiMH

Batteries (2)

800

Notes

LT-800LT-

LT-700

29

LT-800

00

LT-700

Notes

30

LR-400/500 User’s Manual Table of Contents

Specifi cations 37
Block Diagram 39
Quick Reference 40
Setup Instructions 42
Operating Instructions 45
Programming Instructions (LR-500 only) 51
Accessories 52
Notes 53

LR-400/500 Package Contents

• LR-400/500

• Quick Reference Card

• Warranty Card

LR-400-863

Portable Display

FM Receiver

(863 MHz)

Listen Confi gurations

• LR-400-863

• LR-500-863

LR-400/500

LR-500-863

Portable Programmable

Display FM Receiver

(863 MHz)

35

LR-400-863 Specifi cations

Architectural Specifi cation

The LR-400-863 FM receiver shall be capable of receiving on 17 wide band channels with a SNR of
70 dB or greater. The device shall be able to be locked on a single channel. The receiver shall be
capble of seeking channels. The device shall have an adjustable squelch. The device shall have an
audio frequency response of 50 Hz to 15 KHz, ±3 dB. The device will incorporate a stereo headset jack
that allows the user to plug in either a mono or stereo headset. The device shall incorporate an LCD
display that indicates channel, battery level, low battery, battery charging, and RF signal strength.
The receiver shall be able to function in both DX and Local mode. The unit shall operate off of 2 AA
batteries. The receiver shall incorporate automatic battery charging circuitry for recharging of NiMH
batteries. The Listen LR-400-863 is specifi ed.

Specifi cations LR-400-863

RF Frequency Range 863.050 - 864.950 MHz
Number of Channels 17 Wideband
Sensitivity .6uV typical, 1 uV maximum for 12 dB sinad

RF

Audio

Frequency Accuracy ± .005% stability 32 to 122º (0 to 50º C)
Antenna Integrated External Antenna
Squelch Programmable in 20 steps, automatic on loss of RF signal
Compliance CE, ETSI, RoHS

System Frequency Response 50 Hz - 15 kHz (+/-3 dB)
System Signal to Noise Ratio 70 dB (A-Weighted)
System Distortion <2% total harmonic distortion (THD) at 80% deviation

Output

3.5 mm connector, unbalanced, 0dBu nominal output level, 16
mW maximum, impedance 32 Ohms

Controls

Indicators

Power

Physical

Environmental

User Controls Channel up/down, SEEK, volume
Set-up Controls (battery compartment) Alkaline/NiMH battery switch
Programming Channel Lock, DX/Local, squelch

LED

LCD Display

Battery Type Type: 2 AA batteries, alkaline or NiMH
Battery Life (Listen batteries)
Battery Charging (NiMH only) Fully Automatic, 13 hours maximum

Dimensions (H x W x D) 5.0 x 3.0 x 1.0 in (13 x 7.6 x 2.5 cm)
Color Dark Grey with white silk screening
Unit Weight 3.9 oz (111 g)
Unit Weight with batteries 5.8 oz (164 g)
Shipping Weight 1.0 lbs. (0.45 kg)

Door

Temperature - Operation -10 C (14 F) to +40 C (104 F)
Temperature - Storage -20 C (-4 F) to +50 C (122 F)
Humidity 0 to 95% Relative Humidity, non condensing

Specifi cations are subject to change without notifi cation

Red, illuminated when unit is on. Flashes when batteries are
low, or Charging. Flashes when locked and SEEK is pushed.

Channel Designation, lock status, signal strength indication,
battery life

20 hours alkaline (LA-361), 10 hours NiMH rechargeable
(LA-362)

Manually Lockable. Up, down, and power buttons through
door. Other controls behind door (see controls)

LR-400/500

37

00

LR-500-863 Specifi cations

Architectural Specifi cation

The LR-500-863 FM receiver shall be capable of receiving on 17 wide band channels with a SNR of
70 dB or greater. The receiver shall be programmable to electronically lock out unneeded channels.
The receiver shall be capable of seeking channels. The device shall be able to be locked on a single
channel. The device shall have an adjustable squelch. The device shall have an audio frequency
response of 50 Hz to 15 KHz, ±3 dB. The device will incorporate a stereo headset jack that allows the
user to plug in either a mono or stereo headset. The device shall incorporate an LCD display that
indicates channel, battery level, low battery, battery charging, and RF signal strength. The receiver
shall be able to function in both DX and Local mode. The unit shall operate off of 2 AA batteries. The
receiver shall incorporate automatic battery charging circuitry for recharging of NiMH batteries. The
Listen LR-500-863 is specifi ed.

Specifi cations LR-500-863

RF Frequency Range 863.050 - 864.950 MHz
Number of Channels 17 Wideband
Sensitivity .6uV typical, 1 uV maximum for 12 dB sinad

RF

Frequency Accuracy ± .005% stability 32 to 122º (0 to 50º C)
Antenna Integrated External Antenna

Squelch
Compliance CE, ETSI, RoHS

Programmable in 20 steps, automatic on loss of RF signal

LT-800

LR-400/500

Audio

Controls

Indicators

Power

Physical

System Frequency
Response

System Signal to Noise
Ratio

System Distortion <2% total harmonic distortion (THD) at 80% deviation
Output

User Controls Channel up/down, SEEK, volume
Set-up Controls (battery

compartment)
Programming Channel Lock Out, Channel Lock, DX/Local, squelch

LED

LCD Display

Battery Type Type: 2 AA batteries, alkaline or NiMH
Battery Life (Listen

batteries)
Battery Charging (NiMH

only)

Dimensions (H x W x D) 5.0 x 3.0 x 1.0 in (13 x 7.6 x 2.5 cm)
Color Dark Grey with white silk screening
Unit Weight 3.9 oz (111 g)
Unit Weight with batteries 5.8 oz (164 g)
Shipping Weight 1.0 lbs. (0.45 kg)

Door

50 Hz - 15 kHz (+/-3 dB)

70 dB (A-Weighted)

3.5 mm connector, unbalanced, 0dBu nominal output level, 16 mW
maximum, impedance 32 Ohms

Alkaline/NiMH battery switch

Red, illuminated when unit is on. Flashes when batteries are low, or
Charging. Flashes when locked and SEEK is pushed.

Channel Designation, lock status, signal strength indication, pro­gramming

20 hours alkaline (LA-361), 10 hours NiMH rechargeable (LA-362)

Fully Automatic, 13 hours maximum

Manually Lockable. Up, down, and power buttons through door.
Other controls behind door (see controls)

Temperature - Operation -10 C (14 F) to +40 C (104 F)

Environmental

38

Temperature - Storage -20 C (-4 F) to +50 C (122 F)
Humidity 0 to 95% Relative Humidity, non condensing

Specifi cations are subject to change without notifi cation

LR-400/500 Block Diagram

115/230VAC

50/60 Hz

LCD Display

Universal

Power Supply

(not included)

ANTENNA

RF

de-modulation

Power Supply

CPU Module

Alkaline

(2) AA Batteries

ALkaline or NiMH

NiMH

de-emphasis

Companding

Q-Technology

Up

Down

Seek

Power charge indicator

Red LED

POWER

On

Off

VOLUME

3.5 mm Connector

Tip

Ring

Sleeve

LR-400/500

39

00

LR-400-863 Quick Reference

Articulating Flexible Antenna

Power/Charging Port

Front Door Lock

Channel Select Buttons

3.5 mm Output Jack: Connect a listen earpiece here.
LED: When lit, indicates unit has power.

On/Off and Volume Control Dial

Look&Listen™ Display: Shows
receive level, channel, battery
status, and lock status.

SEEK Button: Allows the
user to change channels
or lock on a channel.

Battery Select Switch: Choose
the type of batteries being
used.

Battery Compartment: Place
2-AA batteries in compartment.
Be sure to follow polarity
pattern.

LT-800

LR-400/500

Channel Display: Displays the
channel the LR-400 is currently on.

RF Input Indicator:
Indicates the RF receive
level.

40

Battery Level Indicator

Lock Icon: Indicates the unit is
locked on current channel.

LR-500-863 Quick Reference

Articulating Flexible Antenna

Power/Charging Port

Front Door Lock

Channel Select Buttons

3.5 mm Output Jack: Connect a listen earpiece here.
LED: When lit, indicates unit has power.

On/Off and Volume Control Dial

Look&Listen™ Display:
Shows receive level, channel,
programming, battery
status, and lock status.

SEEK Button: Allows the
user to change channels
or lock on a channel.

Battery Select Switch: Choose
the type of batteries being
use

d.

Battery Compartment: Place
2-AA batteries in compartment.
Be sure to follow polarity
pattern.

Channel Display: Displays the
channel the LR-500 is currently on.

RF Input
Indicator:
Indicates the
RF receive
level

.

Program:
Function is
in process.

L/O: Indicates while in programming
mode the specifi c channel has
been locked out.

Lock Icon: Indicates the unit is
locked on current channel

LR-400/500

Battery Level Indicator

41

00

LR-400/500 Setup Instructions

1

Remove the product

Remove outer packaging and plastic cover. Inspect for physical damage. If damage is apparent,
please contact the dealer from which the product was purchased or Listen Technologies Corpora­tion technical support for assistance (refer to page 67 for contact information).

Open the front access door

2

If locked, use a pocketknife or small screwdriver to unlock the door locks on both sides of
the unit. To unlock the door, rotate the lock ¼ turn counterclockwise. Grip the two tabs with
your thumb and index fi nger and pull the door downward. DO NOT place batteries in the
unit at this time.

LT-800

LR-400/500

Select Battery Type

3

Two types of batteries may be used: The unit is shipped with the switch in the Alkaline position.
Use a pen or small screwdriver to select the battery type.

Battery select switch

WARNING: Do not place the BATTERY switch in the NiMH position if you are not using

Nickel Metal Hydride Batteries. The NiMH position will attempt to charge
any batteries in the unit, even if they are not the proper type. Charging
non-Nickel Metal Hydride (NiMH) batteries will result in physical harm,
destruction of property and/or fi re.

CAUTION: If you are using any battery type other than rechargeable Nickel Metal

Hydride (NiMH) batteries, make sure the BATTERY selection switch is in the
alkaline position.

42

LR-400/500 Setup Instructions

Place Batteries in Unit

4

Place two AA batteries in the compartment, making note of the battery polarity shown in the battery
compartment, and again verifying that the BATTERY SELECT switch is in the correct position for the
batteries you are using. (Alkaline should be selected for all battery types other than NiMH).

NOTE: Listen provides industrial strength AA alkaline batteries (part number LA-361) and high
performance AA Nickel Metal Hydride batteries (part number LA-362). These may be
purchased from your Listen dealer.

-

-

+

+

+

+

-

-

5

Connect an Earphone or Headset

Your headset or earphone will connect to the jack on the top of the unit. Either mono or stereo
connectors may be used with a Listen receiver. Make certain you push the plug all the way into
the jack.

LR-400/500

43

00

LR-400/500 Setup Instructions

6

Turn the Unit On

Receivers are turned on by rotating the volume dial counterclockwise. The red LED on top of the unit will
illuminate and the LCD display should illuminate. If they do not, make sure you have installed the batter­ies correctly and that you are using fully charged batteries.

LT-800

LR-400/500

44

LR-400/500 Operating Instructions

1

Turn Unit On

1A

Volume knob

Rotate the volume knob counterclockwise with an earphone or headset connected to
the unit.

WARNING: Excessive volume may result in hearing damage.

Antenna Placement

2

2A

Antenna Position

Raise the antenna to the upright position. When the antenna if fully extended, it will
click into position.

NOTE: Be aware that the transmission range could decrease if the antenna is

not in an upright position.

3

Select a Channel

3A

Select the channel using channel select buttons

Select the channel to match the transmission channel by pressing the UP and DOWN
buttons on the receiver.

LR-400/500

45

00

LR-400/500 Operating Instructions

Select the channel using SEEK

3A

Another way to fi nd a channel on the LR-400/500 is to use the SEEK button.
When you do this, the Listen receiver looks for the next active channel.
Sometimes the unit will mistake interference for a real broadcast signal. If you
get interference, press the SEEK button again. The unit may stop on a
channel that is close to the actual broadcast channel, in which case the
channel will sound noisy or distorted. Simply press SEEK again until you fi nd the
clearest operating channel.

LT-800

LR-400/500

4

Adjust the volume control

Use the control dial on the top of the unit to adjust the volume to a comfortable level.

46

LR-400/500 Operating Instructions

Locking the Receiver on One Channel

The unit can be electronically locked on one channel so that it will not change channels even if the “SEEK” button is
pressed. It is recommended to lock the receiver on a channel that is being used in a single channel system or when mul­tiple systems are in the same area.

1

To lock on a channel

1A

Press and hold the SEEK button for 5 seconds

Press and hold the SEEK button for 5 seconds to lock a receiver onto the currently tuned
channel. Press and hold the button again to unlock. When locked the LED on top of
the unit will fl ash when you press the SEEK button.

NOTE: On the LR-400/500, when the channel is locked, a lock icon will appear underneath
“Listen” on the display. Also if the unit is locked, the red LED on top of the receiver will

fl ash when the SEEK button is pressed.

LR-400/500

47

00

LR-400/500 Operating Instructions

Squelch Programming

Entering Squelch Program Mode

1

Turn unit off

Press and hold the SEEK button; while holding SEEK button down, turn the ON/OFF/VOLUME dial to turn

2

the unit on.

3

Release the SEEK button when the Listen name disappears (approximately 2 seconds) and a two digit
display is seen.

Adjusting the Squelch level

Use the Channel UP and DOWN buttons to raise or lower the squelch sensitivity settings (refer to the chart on

1

page 49 for settings.
Lower numbers mean that a less powerful and possibly noisy signal will be heard, but you can have a

2

longer range before the unit will squelch.

Once the desired squelch setting is found, press SEEK to exit the squelch programming mode.

3

LT-800

LR-400/500

NOTE: Keep in mind, low squelch may allow multipath and squelch chattering at long distances.

Squelch setting 00 is no squelch; this setting disables the squelching capabilities of the receiver. Squelch
setting 20 is maximum squelch sensitivity; when on this setting, there must be a very strong and stable
RF signal for the unit to not engage the squelch feature.

NOTE: For squelch settings 1-3, the squelch function is slow which allows for maximum
transmission range. For squelch settings 4-20 the squelch function is fast to ensure little

radio noise is heard during the squelch function.

48

LR-400/500 Operating Instructions

Squelch

The purpose of squelch is to mute the audio output of your receiver when the signal from the
transmitter is turned off or is too weak to be received. Without squelch you would hear radio noise
in your earphone. The squelch on your receiver can be adjusted so that it will mute the audio on
different RF signal strengths. This is useful as follows:

Set the squelch setting to the highest level

To ensure that users don’t hear transmissions from other
transmitters, set the squelch setting to the highest level that
doesn’t squelch the receiver.

If the receiver is close to the transmitter, set the squelch high

If the receiver is going to be close to the transmitter (i.e. in
a classroom), set the squelch setting high so that when the
transmitter is turned off it immediately squelches and ignores
transmitters in other rooms.

Squelch

Setting

0

1

2
3

(default)

4

5

6

Squelch

No Squelch

Loose Squelch

(Most Range)

If in an area that has a lot of interference, set the squelch high

If you are in an area that has a lot of inference, you may want to
set the squelch setting to a high setting to ensure the
interference is not picked up by the receiver.

For maximum amount of range, set the squelch to a low level

If you need the maximum amount of range, you may want to
consider setting the squelch setting to a low level (0, 1 or 2).

NOTE: Default squelch setting is 3

CAUTION: When setting the squelch level low the reliability of squelch
function is compromised. This will cause radio noise to be heard

in the earphone and there is a possibility of hearing damage.

10

11

12

13

14

15

16

17

18

7

8

9

LR-400/500

(Least Range)

Tight Squelch

19

20

49

00

LR-400/500 Operating Instructions

DX/Local

DX is the normal operational mode. Local mode can effectively limit any inter-modulation and/or
interference in a busy RF environment. This is done by limiting the amount of RF gain in the receiver.
When local mode is selected, the range of the receiver is compromised. Depending on your application
and environment, Local mode may be necessary for better performance. DX mode is default.

DX Mode (default)

DX is normal operation. The local mode feature can be used
when many frequencies are being used.

Local mode

Only strong channels will be automatically tuned in

1

To change to DX/Local mode

1A

While the unit is OFF, press and hold the channel down button and turn the unit on.

The LCD shall indicate the current setting “D” or “L”.

1B

Pressing the down button will toggle between Local and DX Mode; “D” or “L”.

1C

1D

Pressing seek will enter the setting and return to normal operational mode.

LT-800

LR-400/500

Resetting to defaults

To reset the receiver to default settings, follow these instructions:

Reset to default settings

1

1A

Press and hold the Up and Down channel buttons while turning the unit on.

Press and hold the Up and Down channel buttons while turning the unit on. This will light
up all segments of the display.

1B

After the receiver has been reset

After the receiver has been reset, the display will return with defaults present.

NOTE: The defaults are

• Channel: 01
* Channel lockout: All channels active

LocalDX

50

LR-500 Programming Instructions (LR-500 only)

Programming Instructions

The LR-500 can be programmed to receive on a limited number of channels. When an
application requires the use of more than one channel (i.e. a classroom or language
interpretation), the receiver can be programmed to view only the necessary channels.

Entering Program Mode

To enter program mode

1

While the unit is ON, press and hold the channel down and up buttons simultaneously for 3 seconds.

1A

The “PGM” icon on the LCD will appear indicating program mode is active.

1B

2

To program

2A

Once in the program mode, a function menu is displayed. Function 1 (F1) is displayed as default.
Pressing the channel up or down buttons will scroll through the functions (F1).
Pressing the seek button will enter that particular function.

F1- Channel Lock out. No channels are locked out as default. Pressing the up and down buttons will scroll through
channels. Pressing the seek button will toggle between available and locked out for that channel. When a chan­nel is locked out, the L/O on the LCD shall be displayed.

NOTE: Although it is possible to display an F2 function while in program mode, there is no F2 function at this

time. Listen may add another programming function in the future, but there is only one programming
function (F1) on the 863 MHz receivers.

When no button is pressed for 10 seconds, the program menu is exited altogether, regardless of whether a

3

function is entered or not. To exit out of the program menu or function manually:

3A

When in the programming menu: Press and hold power for 2 seconds. This exits the program mode.

3B

When in a programming function: Press and hold power for 2 seconds. This exits the function and goes back to
the programming menu.

Pressing and holding power for a full 4 seconds will exit both programming function and programming menu.

3C

LR-400/500

51

00

Accessories for LR-400/500

-1

70

ead

Accessories

LT-800

LR-400/500

LA-164

Ear Speaker

LA-170

Behind-the-H

Behind-the-Head

Stereo Headphones

LA-165

Stereo Headphones

LA-304

Assistive Listening

Notifi cation Signage Kit

LA-166

Neck Loop

LA-361

High Capacity AA Alkaline

Batteries (2)

LA-362

Rechargeable AA NiMH

Batteries (2)

LA-311 16-Unit Portable Charging/Carrying Case
LA-313 16-Unit Portable Carrying Case
LA-317 4-Unit Portable Charging/Carrying Case
LA-318 4-Unit Portable Carrying Case
LA-320 Confi gurable Carrying Case
LA-321 8-Unit Portable Charging/Carrying Case
LA-322 8-Unit Portable Carrying Case
LA-323 4-Unit Portable Charging/Carrying Case w/Removable Lid
LA-324 8-Unit Portable Charging/Carrying Case w/Removable Lid
LA-325 16-Unit Portable Charging/Carrying Case w/Removable Lid

52

Notes

LR-400/500

53

00

Notes

LT-800

LR-400/500

54

LR-400/500

0

LR-400/50

57

Supplementary Information Table of Contents

Frequency Chart 61
Battery Charging Information 62
Troubleshooting 63
Frequently Asked Questions 65
Compliance, Warranty and Contact Information 67
Notes 68

Supplementary

59

Frequency Chart

Frequencies

Supplementary

61

00

Battery Charging Information

The LT-700 and LR-400/500 receivers are unique because they have SmartCharge™ chargers built in. When any of these units are placed
into a Listen charging case, NiMH batteries will be charged.

SmartCharge™ uses a pulse charging, which greatly extends the life of Nickel Metal Hydride (NiMH) batteries. The entire charging process
takes about 13 hours. Listen recommends that you allow the charger to complete its full cycle every time for maximum battery life.

During the charge cycle, the red LED on top of the Listen product will fl ash slowly. When charging is completed, the LED will turn off. It is not
necessary to unplug the charger; however, if you unplug the unit from the charger and then plug it back in, it will begin the 13-hour charge
cycle over again.

When not using the receiver, it is recommended to leave the unit on the charger. The charger provides a “maintenance”
charge that keeps the battery at 100%. If the unit is not on the charger, the battery will lose up to 20% of its charge per month.

NOTE: Listen provides 2300 mAH (milli-Amp-hour) constant current (NiMH Nickel Metal Hydride) batteries.
These may be purchased from Listen (part number LA-362).

Charging with a drop-in charger

To charge the batteries using a drop-in charger, simply place the unit into a slot in the charger and connect
the charger to power. Make sure the unit is fully seated in its slot.

IMPORTANT: DO NOT ATTEMPT TO CHARGE ANY TYPE OF BATTERY OTHER THAN NiMH (NICKEL METAL HYDRIDE) with

IMPORTANT: In order to charge NiMH batteries, the BATTERY SELECT switch in your Listen product must be set to the

WARNING: The case lid MUST be open or removed while the units are charging. The charging process generates

your Listen equipment. Alkaline batteries may explode when connected to a charger. Other risks of
charging non-NiMH batteries include destruction of property or fi re.

NiMH setting. Use a pen or small screwdriver to move the switch (located in the battery compartment)
to the proper position.

heat. Air ventilation is required. It is best to store your charging case at room temperature away from
heat sources and direct sunlight.

LT-800

Supplementary

62

Troubleshooting

Troubleshooting

The unit has no power.

Make sure the unit has fully charged batteries. Press the POWER button. If this does not work, try a
different set of batteries. Make sure the batteries are installed correctly.

There is no audio.

Make sure the MUTE/TALK switch is in the TALK position. Make sure you have the microphone plugged

all the way into the input jack. Make sure you are using a Listen approved microphone (see list on
page 21). If you are using the line input, make sure you have connected a line level, unbalanced input
at the “ring” of the connector. Also,be sure the receiver is on, volume is turned “up”, and headphones
are placed fi rmly in the jack .

The audio is distorted.
Make sure you are using an approved Listen microphone. Try using a different mic sensitivity switch
setting (the switch is located inside the battery compartment of the unit). If you are using a line level

input, try turning down the level of the input. Make sure the receiver is “ON” and receiving the

appropriate channel.
There is hum in the audio.

The microphone may be too close to a transformer. Try moving away from the transformer and see if

the hum goes away.

The microphone level is low.
The mic sensitivity switch may be on the wrong setting, (see page 21). Try a different setting (the switch

is located inside the battery compartment). Some microphones have directional pickups, ensure that
the microphone in use is oriented and positioned properly (pointing at the speakers mouth).

The microphone must be in close proximity to the person who is speaking. If this does not work, try using

a head-worn microphone.

There is too much noise.
This is most likely because the microphone is not close enough to the talker’s mouth, and it is picking up

background noise. Try positioning the microphone closer or try using a microphone that is directional
(such as a head-worn mic). Try another setting on the mic sensitivity switch (located inside the battery
compartment).

There is interference.
Try different frequencies to fi nd a clear channel. Use a receiver to sweep the area without any
transmitters “on”. The receiver will stop on any channels that are being broadcasted in the area.
Avoid the channels that the receiver detects having a signal.

I cannot pick up the signal on the receiver.
Make sure the transmitter and the receiver are on the same frequency channel.

It’s confusing for users to have 17 available channels.
Use the PROGRAM function (LT-700 and LR-500 only) to lock out unwanted channels. Users will only be

able to scroll through available channels.

I cannot change the channel.

The transmitter or receiver may be locked on a channel (check for the padlock icon). To unlock, press

and hold the UP or DOWN button for 5 seconds.

Supplementary

63

00

Troubleshooting

Troubleshooting

My batteries are not charging

Make sure you are using NiMH batteries and that the BATTERY SELECT switch (inside the battery

compartment) is set to the NiMH position. Make sure the batteries are installed correctly. Make sure
you are using a Listen charging case. Make sure the charging case is connected to power and
the unit is securely pushed into its slot in the case.

NOTE: Listen uses 2300 mAh (milli-Amp-hour) constant current NiMH (Nickel Metal Hydride) batteries. These

may be purchased from a Listen dealer (ask for part number LA-362).

LT-800

Supplementary

64

Frequently Asked Questions

Frequently Asked Questions

Do I need a transmitter for each audio source?

Q

Q

Q

Q

Yes. To transmit two different frequencies, there must be two separate transmitters.

A

What is the range of the LT-700 Transmitter?

The range of the LT-700 will depend upon the power setting and interference (refer to page 8).

A

Generally the range is up to 61 m (200 ft.).

Is there a limit to the number of transmitters I can use in one room?

Yes. Listen recommends that no more that 8 channels are in used simultaneously (refer to page 9 on

A

using multiple channels in the same room).

What reciever should be used with multiple trasmitters?

We recommend the LR-500 for use with multiple transmitters, because the LR-500 is programmable

A

and can lock out unused channels.

How many channels can I program into the LR-500?

Q

Q

Q

Q

1 to 17. The receiver has 17 channels and you can program it to have just the channels you want

A

to have access to. It can be a two channel receiver, a 12 channel receiver, or keep all 17.

How many receivers can I have in a system?

As many as you need, the number is endless.

A

What are the major differences between the LR-400 and the LR-500?

Both receivers can tune to 17 broadband channels. However, the LR-400 has the buttons under

A

the battery compartment door and the LR-400 is not programmable to lock out channels. If you
plan to use one receiver with multiple transmitters you should use the LR-500 which is

programmable to just those channels you need.

What is the battery life of the LT-700 Transmitter?

Fifteen hours alkaline. Eight hours NiMH.

A

Supplementary

65

00

Frequently Asked Questions

Frequently Asked Questions

Can the receiver be “locked” on a channel if needed?

Q

Q

Yes. All Listen receivers can be locked on a single channel.

A

What is the battery life of a receiver?

20 hours using alkaline batteries. 10 hours using NiMH batteries.

A

LT-800

Supplementary

66

Compliance, Warranty and Contact Information

Compliance Information

The following compliance information applies to the LT-800-863, LT-700-863, LR-500-863 and LR-400-863
These devices comply with ETSI EN 301 357
These devices are CE compliant.
These devices are RoHS compliant.

Warranty

Listen Technologies Corporation (Listen) warrants its transmitters and receivers (models LT-700, LT-800, LR-42, LR-44,
LR-100, LR-300, LR-400, LR-500 and LR-600) to be free from defects in workmanship and material under normal use
and conditions for the useful lifetime of the product from date of purchase.

Listen warrants it’s Stationary IR Radiators (LA-140) to be free from defects in workmanship and material under nor­mal use and conditions for three years from the date of purchase.

Listen warrants its Noise Canceling Microphone (LA-270) to be free from defects in workmanship and material under
normal use and conditions for one year from date of purchase.

All other products and accessories are warranted for 90 days from date of purchase.
This warranty is only available to the original end purchaser of the product and cannot be transferred. Warranty is

only valid if warranty card has been returned, or online warranty registration, has been completed within 90 days
of purchase. This warranty is void if damage occurred because of misuse or if the product has been repaired or
modifi ed by anyone other than a factory authorized service technician. Warranty does not cover normal wear and
tear on the product or any other physical damage unless the damage was the result of a manufacturing defect.
Warranty does not include inbound freight costs. Listen is not liable for consequential damages due to any failure
of equipment to perform as intended. Listen shall bear no responsibility or obligation with respect to the manner of
use of any equipment sold by it. Listen specifi cally disclaims and negates any warranty of merchantability or fi tness
of use of such equipment including, without limitation, any warranty that the use of such equipment for any purpose
will comply with applicable laws and regulations. The terms of the warranty are governed by the laws of the state of
Utah.

In the fi rst ninety days after purchase, any defective product will be replaced with a new unit. After 90 days, Listen
will, at its own discretion either repair or replace transmitters and receivers with a new unit or a unit of similar type
and condition. Product that is not covered under warranty shall be repaired or replaced with a unit of similar type
and condition based on a fl at fee.

This limited warranty, prices and the specifi cations of products are subject to change without notice.

Contacting Listen

If technical service is needed, please contact Listen. Pre-authorization is required before returning Listen products. If products were
damaged in shipment, please contact the carrier, then contact Listen for replacement or repair requirements payable by the
carrier.
All Listen European markets are supported through the Listen Technologies GmbH offi ce located in Oberasbach, Germany. For
more information on Listen solutions, contact Listen Technologies at +1.801.233.8992, +1.800.330.0891 North America,
Listen Technologies GmbH at [phone] or visit www.listentech.com. For Europe, Middle East, Africa and India offi ce visit
www.listentech.de.

14912 Heritagecrest way
Salt Lake City, Utah U.S.A. 84065-4818
+1.801.233.8992
+1.800.330.0891
+1.801.233.8995
[e-mail]
www.listentech.com

North America
Fax

Listen Technologies GmbH
Jasminstr.16, 90522 Oberasbach, Germany
[phone]
[phone]
[e-mail]
www.listentech.de

Europe

Fax

Supplementary

67

00

Notes

LT-800

Supplementary

68

Listen Technologies Corporation
14912 Heritagecrest Way
Bluffdale, Utah 84065-4818, U.S.A.
+1.801.233.8992

1.800.330.0891
+1.801.233.8995

North America
Fax

www.listentech.com
[e-mail]

Printed in the United States of America

© 2011 Listen Technologies Corporation

®

All Rights Reserved 201109.28