Listen Technologies LR-100 User 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
satisfied. 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,
efficient 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.
Here’s how to reach us:
801.233.8992
800.330.0891 North America
801.233.8995 fax
[email protected]
www.listentech.com
Thank you and enjoy your listening experience!
Best regards,
Russell Gentner and the Listen Team
• 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 less than 10 days!
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Assistive Listening • Language Interpretation • Soundfield • Tour Group • Conferencing

1
Table of Contents Package Contents Specifications Quick Reference Setup/Installation Supplementary Information
Programming
Package Contents 3
Specifications
Architectural Specifications 4
Specifications 4
Quick Reference 5
Block Diagram 7
Setup 8
Installation 10
Speaker Connection 11
Antenna Installation 11
Programming 12
Squelch Adjustment 13
Troubleshooting 14
Listen SQ™ 15
Channel Selection 16
RF Reception Maximization Strategies 17
Resetting After an Overload Condition 17
Coaxial Cable 18
72 MHz Frequency Compatibility Table 19
216 MHz Frequency Compatibility Table 20
Supplementary Information
Compliance Notice 21
FCC Statement 21
Warranty 22
Contacting Listen 22
Optional Accessories 23
LR-100 Table of Contents

3
Package Contents
LR-100 Package Contents
Optional Accessories
See page 23
Listen Part Number
LR-100-072 (72 MHz)
LR-100-216 (216 MHz)
LR-100 Contents
• LR-100-072 (72 MHz) or
• LR-100-216 (216 MHz)
• 120 VAC Power Supply
• LA-123 90 Degree Helical Antenna (72 MHz) or
• LA-124 90 Degree Helical Antenna (216 MHz)
• Allen Wrench
• Warranty Card
• User Manual

4
Specifications
Specification LR-100-072 LR-100-216
RF Frequency Ran
g
e 72.025 - 75.975 MH
z
216.025 - 216.987 MH
z
Number of Channels 57
(
17 wide, 40 narrow
)
57
(
19 wide, 38 narrow
)
Sensitivity
Frequency Accurac
y
Antenna Flexible helical,
9.0 in.
(
23 cm
)
included
Flexible helical,
5.5 in.
(
14 cm
)
included
Optional Antennas
Antenna Connector
Squelch
Compliance
System Frequency Response 63Hz - 15kHz
(
±3dB
)
63Hz - 10kHz
(
±3dB
)
System Signal-to-Noise Ratio
(
A-wei
g
hted
)
SQ enabled: 80dB; SQ disabled 60dB SQ enabled: 80dB; SQ disabled 50dB
System Distortion
Auxiliary Input to Output
Balanced Auxiliary Input
Unbalanced Auxiliary Input
Balanced Output
Unbalanced Output
Headphone Output
Speaker Output
Set-up Controls,
Front Panel behind Securit
y
Set-up Controls, Back Panel
User Controls
Remote Controls
Programming
VU Meter
Power
LCD Display
Squelch
Mute
Power Supply Type
Power Supply Input
Power Supply Output
Power Supply Connector
Compliance
Optional Battery
Optional Battery Char
g
in
g
Dimensions W x D x H
Unit Wei
g
ht
Unit Wei
g
ht w/LA-201 Power
Shippin
g
Wei
g
ht
Rack Mounting
Temperature - Operation
Temperature - Stora
g
e
Humidity
Receive level, auxiliary input level, SQ on/off, squelch
Audio output select (RX Only, RX + AUX, RX or AUX),
Speaker (Output, Aux), switchable balanced output level
Controls
4.2 lbs. (1.9 kg)
Power
Physical
Green LED illuminates when the output audio is muted
Eight position detachable terminal block, channel up, channel down, mute
Volume, channel UP/DOWN, SEEK (all controls except volume are lockable)
8.50 x 9.12 x 1.75 in. (21.6 x 21.16 x 4.45 cm)
Environmental
RF
Audio
Indicators
± .005% stability 0° to 50° C (32° to 122° F)
Rear panel, One detachable terminal block, bridged, adjustable output level,
15/10 watts (peak/RMS) continuous power with 4 ohm load
Rear panel. Two Phono connectors, unbalanced, -10dBu nominal input level
adjustable, +7dBu maximum, impedance 10k Ohms
Rear panel. One Male XLR, balanced, 0dBu nominal output level, +16dBu
maximum, impedance 2k/10 Ohms (line/mic)
Continuously adjustable via front panel trim pot
Frequency Response: 25Hz to 20kHz (±3dB), SNR: >80dB, Distortion: <0.2%
Rear panel. One Female XLR-1/4 in combo connector, balanced, 0dBu
nominal input level adjustable, +13dBu maximum, impedance 600 Ohms
FCC Part 15, Industry Canada
<2% total harmonic distortion (THD) at 80% deviation
0-95% relative humidity, non-condensing
2.8 lbs. (1.3 kg)
5.6 lbs. (2.5 kg)
1/2 rack unit (RU), optional rack mount not include,
order Listen
p
art number LA-326
-20° to +50° (-4° to 122° F)
Unit can be programmed so that only desired channels are displayed to the
user, chaannel selection can be locked by holding the SEEK button 5 seconds.
Four LED (three green, one red)
Green LED illuminates when the unit is powered up
Channel, RF signal strength, lock status, programming
Green LED illuminates when the unit is squelched
12VDC, connected via terminal block
UL Listed
In-line power supply, Listen part number LA-201
120VAC, 60 Hz, 19 watts (maximum continuous)
Trickle charge of optional 12VDC battery through terminal block connection
.6uV typical, 1 uV maximum for 12dB SINAD
Several available. See www.ListenTech.com for details
-10° to +40° C (14° to 104° F)
BNC
Rear panel. Two Phono connectors, unbalanced, -10dBu nominal output level,
+2dBu maximum, impedance 2k ohms
Front panel. One 3.5mm stereo connector, unbalanced, adjustable output
level, +16dBu maximum, impedance 32 ohms, 120mW.
15VAC, 1A
.02 in. OD x .01 in. ID (5.0 x 2.5 mm), barrel type
** All system specifications are wireless end-to-end
LA-122 Specifications
Architectural Specifications
The FM stationary receiver - power amplifier (receiver) shall be capable of receiving on 57 wide and
narrow band channels in the frequency ranges of either 72 MHz or 216 MHz. The receiver shall be
programmable to electronically lock out unneeded channels. The device shall have an adjustable
squelch with an LED indication. The frequency response of the device shall be within 3dB from 63 Hz to
15K Hz at 72 MHz, or within 3dB from 63 Hz to 10 kHz at 216 MHz. The signal to noise ratio shall be 80 dB or
greater. The device will have an integrated power amplifier capable of driving an 8 ohm speaker. The
device shall be rack mountable and shall have the capability of a remote antenna. The device shall
incorporate an LCD display that indicates channel and RF signal strength. The Listen LR-100 is specified.

5
Quick Reference
VU METER: Set Receive and
Auxiliary levels so that the
red LED (at right) does not
illuminate.
MUTE: When lit, the OUTPUT
audio is muted. MUTE is
activated and deactivated
by a momentary closure to
ground on the rear
detachable terminal block
(see next page).
SEEK: Press to find the next
strong signal. Also used to
lock and unlock channel
selection; press and hold for
5 seconds. A padlock will
appear on the display when
locked. Press and hold again
to unlock.
HEADPHONE:
Connect a mono or
stereo headphone
here - 3.5 mm plug
(mini).
Look & Listen™
Display: See details
below
ACCESS PANEL:
Remove to make set-up
adjustments.
POWER SWITCH:
If operated on battery,
switch is inoperative.
SQUELCH: When
adjusted properly,
this LED is lit when
the transmit audio is
not being received.
UP and DOWN:
Channel tuning
buttons.
SPEAKER CONTROL:
Adjusts the volume
of your loudspeaker
connected to the
LR-100, and/or the
headphone.
SQUELCH: Adjust so that when
your transmit audio is off, the
Squelch LED is illuminated. When
squelched, audio is muted (this
keeps you from hearing hiss in your
speakers).
RECEIVE AUDIO LEVEL
ADJUSTMENT
SQ™: To activate, move
switch to ON position.
This switch should be
turned OFF if any of your
equipment does not have
SQ capability. See “Listen
SQ™” on page 15 for more
information.
AUXILIARY
AUDIO LEVEL
ADJUSTMENT
RF SIGNAL STRENGTH Indicates the currently
tuned channel
I/O: While in Program mode,
this symbol indicates that
a channel is locked out and
will not be available to the
user. Press SEEK to toggle
channels between Locked
Out and non-Locked
Out modes.
PGM: When showing,
the unit is in Program
mode to lock out
unwanted channels
from user access.
When the padlock is
visible, the channel is
locked. Press and hold
SEEK for 5 seconds to
unlock or lock.
LR-100 Quick Reference
LR-100 Front Panel
LR-100 Behind Front Access Panel LR-100 LCD Panel Details

6
Quick Reference
SPEAKER SELECTION SWITCH:
This selects the audio being
routed to the speaker
amplifier to either the OUTPUT
or AUXILIARY audio.
Connect provided
power supply here.
OPTIONAL 12V POWER: Connect
optional battery or +12VDC source
here. The battery can be recharged; see
page X.
CONTROL: Remote
control of UP, DOWN
and MUTE functions.
All functions are
momentary closures
to common.
UNBALANCED OUTPUT:
Phono, -10dBu nominal.
AUDIO OUTPUT SELECTION:
For RECEIVE audio only, select RX ONLY;
For RECEIVE audio mixed with
AUXILIARY audio, select RX + AUX;
For RECEIVE audio when not squelched
and AUXILIARY audio when squelched,
select RX or AUX.
SPEAKER CONNECTION:
Connect a 4 ohm (or
greater) loudspeaker here.
ANTENNA CONNECTION:
Attach supplied 90 degree
helical antenna or optional
remote antenna here. Uses
standard 50 ohm BNC
connector.
BALANCED OUTPUT:
Male XLR, 0 or
-40dBu nominal.
Unbalanced AUXILIARY
input: phono, -10dBu
nominal.
BALANCED AUXILIARY INPUT:
Combination Female XLR - ¼ in
connector; 0dBu nominal.
MIC/LINE LEVEL SWITCH:
Reduces the balanced
OUTPUT audio gain by
40dB in Mic mode.
Two internal
2 amp, fast
blow fuses
LR-100 Quick Reference (cont.)
LR-100 Rear Panel

7
Quick Reference
5 6 7 83 41 2
Supply
LA-201
115VAC
Power
On/Off
SQ
On/Off
(internal)
Remote
Antenna
(Flexible helixal
antenna provided)
BNC
Up
Down
Seek
Listen LCD Display
VU
Meter
Output
Balance
d
0 dBu
Output
Unbalanc
e
-10 dBu
Headphon
Receive Level
Auxiliary
Level
Male XLR
3.5MM
Stereo
Mic
Line
Common
Ground
+12 VDC
External Battery
Detachab
l
Electronic
Switch
Phono
Auxiliary
Balance
d
0 dBu
Unbalanc
e
-10 dBu
XLR-1/4"
Combo
RF Receiver
Board
Power Supply
CPU Module
Mute
Squelch
Aux
Output
Squelch
Sensitivity
RX
RX + Aux
RX or Aux
Speaker
Speaker
Output
Select
Phono
Electronic
Switch
Audio Processing
Module
Remote Control
Terminal
Block
External Power
Auxiliary
LR-100 Block Diagram

8
Setup/Installation
LR-100 Setup Instructions
1
If you are using the LR-100’s power amplifier, make sure the unit is given sufficient room around the
ventilation holes.
If you are rack mounting the LR-100, use the optional LA-326 rack mounting kit. This kit allows for single and dual
rack mounting, and comes with a security cover.
For mounting on vertical or horizontal surfaces, use the optional L bracket mounting kit, part number LA-327.
Powering the Unit
NOTE: if the unit will not power up, see Resetting After an Overload Condition, page 17.
AC Power Operation
The unit comes with a UL listed inline power supply designed for 115 VAC, 60 Hz operation. Do not use any other
AC power supply. Use of any non-Listen supplied power supply will void the warranty. (Battery use is permitted; see
below.) Plug the power supply into the back of the unit at the connector labeled POWER. Now connect the power
supply to power.
Battery Operation
To operate the unit on a battery or +12VDC power supply, connect to the rear detachable terminal block as
follows:
i. Pin 3: +12VDC
ii. Pin 4: Ground
NOTE: When operating on the +12VDC battery supply, the POWER switch is bypassed and the unit is always on.
You can optionally charge batteries by also supplying power to unit with the batteries connected. In this case, the
batteries are trickle charged at a rate of 18 - 36 mA. You should only use rechargeable type batteries.
CAUTION: Attempting to charge non-rechargeable batteries may result in explosion and/or fire.
Detachable Terminal Block Wiring:
Pin 1: Speaker +
Pin 2: Speaker ñ
Pin 3: Ground for Battery or Power Source connection
Pin 4: +12VDC Battery or Power Source
Pin 5: UP remote control function
Pin 6: DOWN remote control function
Pin 7: MUTE remote control function
Pin 8: Common for remote control function
Installation - Audio Connections (See Quick Reference on pages 5-6.)
OUTPUT Audio
The OUTPUT audio section is composed of an OUTPUT audio selection switch, a male XLR balanced audio OUTPUT
connector and two phono unbalanced audio OUTPUT connectors.
OUTPUT Audio Selection Switch
This switch selects what audio is routed to the OUTPUT audio connectors. The switch has three positions:
1. RX ONLY. In this position, only RECEIVE audio is routed to the OUTPUT. When the transmitter is turned off, the unit is
squelched and the RECEIVE audio is muted.
2. RX + AUX. In this position, both the RECEIVE and AUXILIARY audio are mixed and routed to the OUTPUT.
3. RX or AUX. In this position, the OUTPUT audio is either RECEIVE or AUXILIARY audio. When the RECEIVE audio is
squelched (indicated by the illumination of the SQUELCH LED on the front panel), AUXILIARY audio is routed to
the OUTPUT. When RECEIVE audio is not squelched, RECEIVE audio is routed to the OUTPUT.

9
Setup/Installation
LR-100 Setup Instructions (cont.)
Balanced Audio Output
When connecting to the XLR balanced OUTPUT, use the pin out shown below. If the output is unbalanced, either
use the unbalanced phono connectors or wire the balanced XLR output as shown below with pins 3 and 1 wired
together. The OUTPUT audio has a nominal output level of 0dBu.
XLR pin out diagram for a balanced connection:
Pin 2 +
Pin 3 -
Pin 1 Shield
XLR pin out diagram for a unbalanced connection:
Pin 2 +
Pin 1 and 3 -
LINE/MIC Switch
This switch reduces the OUTPUT level of the balanced OUTPUT audio only. It does not affect the OUTPUT level of the
unbalanced audio. The OUTPUT audio is reduced by 40dB to microphone level when this switch is selected to MIC.
Unbalanced Audio Output
There are two unbalanced phono audio OUTPUT connectors. The nominal OUTPUT audio level is -10dBu.
AUXILIARY Input
The LR-100 has an AUXILIARY input that allows for greater functionality of the unit for a variety of applications. The
AUXILIARY input consists of a balanced input, combination connector (female XLR and ¼ in) and two unbalanced
phono connectors. All of these inputs are actively mixed together. Thus, any combination of input sources can be
used. Input level is adjusted via the front panel trim pot labeled AUX LEVEL ADJUST. Adjust this level to fit the needs
of your installation ensuring the last red LED on the VU meter is not illuminated (indicating peak audio).
AUXILIARY Balanced Audio Input
The nominal input level for the balanced input is 0dBu.
Female XLR / ¼ in combination connector pin outs:
Pin 2 (tip) +
Pin 3 (ring) -
Pin 1 (sleeve) Shield
AUXILIARY Unbalanced Audio Input:
The nominal input level for the two unbalanced inputs is -10dBu.
Female XLR / ¼ in combination connector pin outs:
Pin 2 (tip) +
Pin 1 and 3 ring/sleeve

10
Setup/Installation
LR-100 Installation - Audio Connections
OUTPUT Audio
The OUTPUT audio section is composed of an OUTPUT audio selection switch, a male XLR balanced audio
OUTPUT connector and two phono unbalanced audio OUTPUT connectors.
OUTPUT Audio Selection Switch
This switch selects what audio is routed to the OUTPUT audio connectors. The switch has three positions:
RX ONLY. In this position, only RECEIVE audio is routed to the OUTPUT. When the transmitter is turned off, the
unit is squelched and the RECEIVE audio is muted.
RX + AUX. In this position, both the RECEIVE and AUXILIARY audio are mixed and routed to the OUTPUT.
RX or AUX. In this position, the OUTPUT audio is either RECEIVE or AUXILIARY audio. When the RECEIVE audio
is squelched (indicated by the illumination of the SQUELCH LED on the front panel), AUXILIARY audio is
routed to the OUTPUT. When RECEIVE audio is not squelched, RECEIVE audio is routed to the OUTPUT.
Balanced Audio Output
When connecting to the XLR balanced OUTPUT, use the pin out shown below. If the output is unbalanced,
either use the unbalanced phono connectors or wire the balanced XLR output as shown below with pins 3
and 1 wired together. The OUTPUT audio has a nominal output level of 0 dBu.
XLR pin out diagram for a balanced connection:
Pin 2 +
Pin 3 -
Pin 1 Shield
XLR pin out diagram for a unbalanced connection:
Pin 2 +
Pin 1 and 3 -
LINE/MIC Switch
This switch reduces the OUTPUT level of the balanced OUTPUT audio only. It does not affect the OUTPUT level
of the unbalanced audio. The OUTPUT audio is reduced by 40 dB to microphone level when this switch is
selected to MIC.
AUXILIARY Unbalanced Audio Input
The nominal input level for the two unbalanced inputs is -10 dBu.
Female XLR / ¼ in combination connector pin outs:
Pin 2 (tip) +
Pin 1 and 3 ring/sleeve
1
2
3

11
Setup/Installation
LR-100 Setup Instructions
LR-100 Speaker Connection
LR-100 Antenna Installation
The LR-100 contains a 44-watt (31 watt RMS), 4 ohm power amplifier.
The Speaker Selection switch determines what audio is directed to the power amplifier. With the switch in the
OUTPUT position, the OUTPUT audio (same audio that is on the OUTPUT audio connectors) is directed to the power
amplifier. With the switch in the AUX position, only AUXILIARY input audio is directed to the power amp. This allows
you to use the power amp separate of the RECEIVER audio if desired.
NOTE: When the speaker switch is in the OUTPUT position and the MUTE control is enabled (indicated by the
illumination of MUTE LED), the speaker output is also muted.
Connection to the speaker is achieved through pins 1 and 2 on the detachable terminal block. Strip the speaker
wires, rotate the screws on the terminal block counter-clockwise, insert the wires and then tighten the screw
clockwise until the wire is secure in the connector block. You may connect any parallel, series combination of
speakers that produces an impedance of 4 ohms or greater.
EXAMPLE: If you have two 8 ohm speakers, you can connect these in parallel to produce a 4 ohm load to the
power amp.
The SPEAKER level control on the front panel adjusts the level of the speaker.
The front panel headphone jack is in parallel with the speaker level. Connect any mono or stereo headphone to
this 3.5 mm jack. Adjust level with the SPEAKER volume knob.
5
4
Installation of Antenna
A properly installed antenna is critical to the operation of the LR-100. Without a strong and consistent RF signal from
the transmitter, the LR-100 will not meet the needs of your installation. You can use the RF POWER indication on the
LCD to provide a relative RF signal strength. You should see four or more dots displayed on the LCD for best results.
Using the supplied helical antenna
Connect the antenna to the rear BNC connector and orient the antenna vertically. If reception is from the
transmitter is not adequate, consider using a remote antenna (see below) or place the LR-100 at an improved
location to improve the signal strength. See RF Reception Maximization Strategies on page 17 for more information.
Using a remote antenna
For better reception in longer broadcast range applications, you should use a remote antenna. A remote antenna
will allow you to get the antenna higher in altitude and in a position that is clear of obstructions. Please refer to the
specific antennas instructions for installation. Also refer to Strategies for Maximizing RF Reception on page 17 for
additional information.
CAUTION: When installing antennas, ensure the antenna is clear of power lines.
NOTES: If the RF signal to the 216 MHz model is too high, the audio will be distorted. This may happen if the LR-100
is within 40 feet of the LT-800-216 transmitter. Consider reducing the output power of the transmitter or
optionally removing the antenna on the LR-100 (there is sufficient internal antenna inside the LR-100 to
receive an adequate signal from the transmitter).

12
Programming
LR-100 Programming
To make setup adjustments, remove the two hex screws that secure the front panel security cover.
Setup VU Meter
The front panel VU meter indicates the audio level of the OUTPUT signal. When making input audio level
adjustments, ensure that the red LED does not illuminate.
Input Audio Levels
Proper adjustment of input levels is critical to the proper operation of the LR-100.
Receiver Audio Level Adjustment. Under normal audio conditions adjust the receive audio level to meet the
output level needs of your installation. Make sure that the red LED on the VU meter does not illuminate.
Auxiliary Input Level Adjustment. Under normal audio conditions adjust the receive audio level to meet the
output level needs of your installation. Make sure that the red LED on the VU meter does not illuminate.
Selecting SQ ON or OFF
See Listen SQ™ on page 15. If the transmitter that is broadcasting to the LR-100 is SQ capable, make sure the SQ
switch for the transmitter and the LR-100 is turned ON. If not, the SQ switch should be turned OFF.
Channel Selection
Select the most appropriate channel by pressing the UP or DOWN button (see Channel Selection on page 16).
You can also press the SEEK button and the unit will SEEK for the strongest RF signal. 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 find the clearest operating channel.
To Lock Into Only One Channel: press and hold the SEEK button for 5+ seconds to lock a receiver into the
currently tuned channel. Press and hold the button again to unlock.
NOTE: It is highly recommended to lock the channel after installation to prevent accidental channel selection.
Programming
In some cases, you may choose to give users the ability to select multiple channels. For example, let’s say you are
using the LR-100 for language interpretation. In this example, channels A, E and I are three different languages.
You can use the LR-100 programming feature to lock out all but the three channels used in this example. By
pressing the UP or DOWN button, the user can select between the three channels.
To Lock Out Channels in the LR-100:
Simultaneously press and hold the UP and DOWN buttons. You will notice the PGM indicator on the LCD
indicating you are in the programming mode (the unit will go out of the programming mode if you don’t press
a key for 10 seconds).
Use the UP and DOWN buttons to select the channels you want to lock out.
As channels are displayed on the unit, those channels that are locked out from user access will be indicated
by the L/O symbol on the display. When a channel is locked out, the LR-100 will skip over that channel when a
user is tuning the unit. Press the SEEK button while in program mode to lock out a channel (lock out means the
channel will NOT be displayed to the user). To reverse the lock out process, press the SEEK button on locked
out channels.
When you have completed programming the unit, don’t press any key for 10 seconds and the unit will exit the
programming mode.
1
2
3
4
5
2a
2b

13
Programming
Squelch Adjustment
Squelch
The squelch adjustment is important to ensure the receiver audio is muted when no signal is present. You want to
set the squelch adjustment for the highest setting without squelching the incoming signal.
To set the squelch control:
Turn the transmitter OFF.
Listen to the receiver audio on the speaker or headphone. Turn the audio level down in the beginning.
Adjust the squelch adjustment clockwise until the squelch LED goes off (not illuminated). You will hear radio
noise now. This is the audio you want to squelch (mute) when the transmitter is off.
Now adjust the squelch setting counter clockwise until it squelches (mutes). This is the minimum
squelch setting.
Now turn the transmitter on. Adjust the squelch setting counter clockwise until the unit squelches. This is the
maximum squelch threshold. Please note that if you are close to the transmitter, you may not be able to find
the maximum squelch threshold due to the high RF signal of the transmitter.
Set the squelch adjustment between the maximum and minimum squelch thresholds, keeping the following
in mind.
Minimum squelch threshold. By adjusting the unit near this threshold, you will maximize the probability
the unit will NOT squelch when the transmitter is on. However, you also run the risk having the unit NOT
squelched (and resulting radio noise coming through the system) when the transmitter is off. You may
experience unsquelching of the receiver by interference as well.
Maximum squelch threshold. By adjusting the unit near this threshold, you will greatly increase the chance
the unit will squelch when the transmitter is off AND you will minimize the probability that the unit will be
unsquelched by interference. However, you are also increasing the chances that the signal coming from
the transmitter will be squelched. Thus, if the RF signal from the transmitter dips just slightly (someone walks
in front of the antenna), you will experience momentary squelching of the audio.
CAUTION: Ensure proper setting of the squelch adjustment to prevent user ear damage and unwanted radio
noise. Users will find unsquelched receiver noise very objectionable.
6
6a
6b
6c
6d
6e
6f

14
Programming
LR-100 Troubleshooting
Troubleshooting
The unit does not power up
Ensure the power supply and/or battery is connected properly. Please note: this product no longer
utilizes internal fuses. The fuses have been replaced with an automatic resetting device that automatically
protects the unit in an overload condition. See Appendix F: Resetting After an Overload Condition for
more details.
The audio is muted occasionally.
Check to see if the unit is squelching (indicated by the squelch LED). In this case, either improve the RF
signal path or adjust the squelch setting for less squelch sensitivity (see page 13).
I hear noise coming from the receiver (with my audio).
You may have inadequate RF signal strength. Adjust the positioning of the antennas. Make sure the
transmitter is on high power. You may be experiencing interference; try a different channel. Make sure the
transmitter and receiver are on the same channel.
The channel is often accidentally changed.
Lock the unit on channel by pressing and holding the SEEK button for five seconds. The padlock symbol is
illuminated on the LCD.
There is no audio.
Make sure the transmitter and the receiver are on the same frequency band (72 MHz or 216 MHz) and
channel. Make sure the RECEIVE and/or AUX trim adjustments are turned clockwise. Make sure the unit
is not MUTED, indicated by the MUTE LED. Make sure the unit is wired correctly. Make sure the squelch
adjustment is set correctly.
The audio is distorted.
Make sure the transmitter and receiver are on the same channel. Make sure that the SQ switch is set the
same way either ON or OFF for both the transmitter and receiver. Make sure the audio level is not set too
high. For the 216 MHz version only, make sure you are not too close to the transmitter (within 40 feet).
The OUTPUT level is low.
Make sure the MIC/LINE switch is in LINE. Adjust the RECEIVE or AUX input levels.
There is no audio on the speaker.
Make sure the speaker selection switch is in the correct position. Ensure that you have a good speaker.
I can’t hear AUX audio on the OUTPUT.
Move the OUTPUT audio selection switch to either “RX + AUX” or “RX or AUX” depending on your
application.
I cannot change channels.
The unit is locked on channel (this is indicated by the padlock icon on the display). Press and hold the
SEEK button for five seconds to toggle the lock off.
The power switch does not work.
This is normal when using the +12 VDC power on the rear terminal block.
If you are still having problems after checking the above items, call Listen for help. We are available from
8am to 5pm Mountain time, Monday through Friday, at 800.330.0891 or 801.233.8992, or you can e-mail us at
[email protected]. Our full contact information is available on page 22 of this manual.

15
Programming
We are accustomed to listening to low noise, high fidelity audio (delivered
via CD, DVD, etc.). FM radio systems, such as those made by Listen, are
inherently noisy compared to most sound systems. To reduce noise of our
systems, Listen now offers a noise reduction technology called ListenSQ™.
Both the transmitter and receiver must have SQ on to achieve the desired
results. SQ is now available on new Listen systems, including the system you
received in this shipment. If you are planning to use this product with older
Listen systems or equipment not manufactured by Listen, you should
disable SQ.
Your Listen equipment has been shipped to you with the SQ feature enabled.
You may need to disable the SQ function for one or more of the following
reasons:
You are using your new Listen system with older version Listen equipment
that does not have the SQ function.
You are using your new Listen system with equipment supplied by other
manufacturers.
You expect that end users may bring and use their own receivers that
don’t have the SQ function.
SQ Summary
• Improves noise performance
by at least 20dB
• SQ is NOT compatible with
older version Listen products
• SQ is NOT compatible with
other manufacturers’
products
• SQ is NOT squelch
• To work properly, SQ must
be enabled for both the
transmitter and receivers
• SQ can be disabled to permit
operation with older Listen
products or other
manufacturers’ products
Listen SQ™ - Improving Your Listening Experience

16
Programming
It is highly recommended that after channel selection has been achieved, you lock the channel
so that it cannot be changed by the user. To accomplish LOCK on the LR-100, press the SEEK
button for 5 seconds. Repeat the process to unlock. It is important to choose channels that are
free from interference to achieve proper operation of your Listen equipment. This process is trial
and error. Before turning on the transmitter, listen to the wide band channels (lettered channels
at 72 MHz and channels that start with a “2” for 216 MHz). Listen to the audio through the
headphone or via the speaker. Choose a channel with the least amount of interface. Unless
you are interfacing with an existing narrowband transmission system, always use a wide band
channel. If you are using multiple channels follow this process:
Same Space. If you are using transmitters in the same space, the most number of channels
that will work simultaneously is six at 72 MHz and three at 216 MHz. With all of the transmitters
off, listen for interference on all the wide band channels via the headphone jack on a Listen
receiver. Using the frequency compatibility tables on pages 19-20, eliminate any channels that
have noticeable interference. Now choose the channels with the widest channel spacing. It is
recommended that adjacent channels be spaced at least 300 KHz. If there is no interference
the following channels are recommended: A, C, E, I, J, and H for 72 MHz and channels 2A, 2K
and 2V at 216 MHz.
Distributed Spacing. If you are using transmitters that are spread out over space, you can
achieve more simultaneous broadcast channels. However, it is critical that your receiver(s) be
located as close to its transmitter as possible. You can use adjacent channels (see frequency
compatibility tables on pages 13-14) in this case as long as the adjacent channel transmitter
is at least 50% further away from the receiver as its transmitter. Example: The transmitter for the
receiver on channel E is 100 feet from the receiver. The adjacent channel transmitter on
channel D should be at least 150 feet away.
Notes in regard to using 72 MHz and 216 MHz systems:
72 MHz in a secondary frequency band. This means that other transmitters are licensed to use
these frequencies. Thus, you may experience interference from paging transmitters and other
type transmissions. You will need to find a clear channel by listening to all the wide band
channels.
216 MHz is a primary frequency band and no other types of transmissions are authorized to
use it. Thus, you will find the highest probability of clear channels in this band. However, you
may experience intermodulation of the TV Channel 13 aural carrier if there is a channel 13
transmitter in your area and you are close to the transmitter. If you cannot find a clear
channel in 216 MHz band due to channel 13, it is recommended that you switch to a
72 MHz system.
Channel Selection

17
Programming
For proper and dependable operation, Listen receivers should receive a strong and
consistent signal from the originating transmitter. The following strategies should be used
maximize this signal:
When designing and installing your system, keep in mind that the location of both the
transmitting and receiving antennas is critical to maximizing signal strength.
Eliminate or minimize obstructions between the transmitting antenna and the receiving
antenna.
Minimize the distance between the transmitting and receiving antennas.
Move transmitting and receiving antennas away from metal objects.
Place the transmitting antenna as high as possible.
Orient both transmitting and receiving antennas vertically.
For 216 MHz unit only, consider using a gain antenna such as a Yagi type antenna.
CAUTION: When installing antennas, ensure the antenna is clear of power lines.
NOTE: If the RF signal to the 216 MHz models is too high, the audio will be distorted. This may
happen if you are within 40 feet of the LT-800-216 transmitter.
Coaxial cable, connectors, and optional antenna mounting kits are available from Listen.
Visit www.listentech.com or ask your dealer for details.
In an overload condition, the LR-100 will go into a protective state to protect the unit and
power supply from excessive current and heat. This condition will occur if the speaker
terminals are shorted to each other or if they are shorted to the chassis for over 15 seconds.
In this condition, the LR-100 will no longer function normally. If the LR-100 stops functioning
normally, do the following:
Turn the unit off and unplug it from power. If you are operating the LR-100 with an external
+12VDC source such as a battery, disconnect the power source from the unit.
Remove the short to the speaker terminals.
Wait 30 seconds or longer.
Plug the unit back in and turn the power on.
The LR-100 should now function normally. If the unit is still not functioning normally, contact
Listen Support.
Resetting After an Overload Condition
RF Reception Maximization Strategies
1
2
3
4
a
b
c
d
e
f
g

18
Programming
The antenna for the LR-100 can be mounted directly on the unit if desired. However, you may
find that the unit will provide better performance when the antenna is located elsewhere. If
you plan to mount the antenna in a different location than on the top of the unit, you must use
cable and connectors rated at 50 ohms. Although cable used for cable TV installations looks
similar to this cable, it won’t work with your Listen system.
If you need to run cable over a greater length than 50 feet for 216 MHz applications or greater
than 100 feet for 72 MHz applications, we recommend that you use RG-8 cable rather than
RG-58. It is a lower loss cable, meaning that more of your signal will reach the antenna.
Long cable runs can result in signal degradation due to “loss” characteristics of the cable. At 72
MHz, there is an average loss of 2 dB per 100 feet of cable and at 216 MHz an average* loss of
5 dB per 100 feet of cable. (A 3 dB loss means half of your power has been lost.) However, it is
better to suffer coaxial power loss than to try to shoot your signal through obstacles! Obstacles,
especially metal, can create drop-outs or reflections of your signal that will result in poor listening
conditions.
*Note: There are large varieties of 50 ohm, RG-58 and RG-8 cables. You may purchase a
cable that is better or worse than this value. Please check with the cable vendor or
manufacturer for exact specifications.
Coaxial Cable