User’s Manual LT-700 Portable Transmitter Listen Technologies Corporation 8535 South 700 West, Suite A Sandy, Utah 84070-2515 USA Telephone: +1.801.233.8992 Toll Free (North America): 1.800.330.0891 Fax: +1.801.233.8995 E-mail: info@ListenTech.com Don’t miss a single sound. Listen.
Welcome to Listen! Dear Valued Customer, Thank you for choosing Listen! All of us at Listen are dedicated to providing you the highest quality products and prompt, efficient customer care. Our products are manufactured in an ISO-9000 factory that has been independently certified to the highest quality standards. We stand ready to answer any questions you might have during installation or in the operation of our products.
Listen Part Number · · · 72 MHz: LT-700-072 216 MHz: LT-700-216 LT-700-072 (72MHz or 216MHz) Warranty Card User Manual Welcome to Listen! LT-700 Package Contents Optional Accessories See pages 32-33.
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Table of Contents Table of Contents Architectural Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Setup Instructions . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications Specifications Architectural Specifications The portable FM transmitter shall be capable of broadcasting on 57 channels. The unit shall incorporate a microphone sensitivity switch. The device shall broadcast on both wide and narrow band channels with a SNR of 80dB or greater. The device shall have an audio frequency response of 50Hz to 15kHz, ±3dB at 72MHz, or of 50Hz to 10kHz, ±3dB at 216MHz. The device will incorporate a mute switch.
Specifications Specifications continued Specification LT-700-072 LT-700-216 ** All system specifications are wireless end-to-end System Frequency Response 63Hz - 15kHz (± 3dB) 63Hz - 10kHz (±3dB) System Signal to Noise Ratio (A-weighted) SQ enabled: 80dB; SQ disabled 60dB SQ enabled: 80dB; SQ disabled 50dB System Distortion Audio Microphone Input Microphone Sensitivity Line Input Phantom Power Set-up Controls, behind the door Controls Indicators Power, mute, channel UP and DOWN Unit can be p
Quick Reference Quick Reference LT-700 Front 3.5mm Input Jack A Listen microphone or line level cable connects here. MUTE / TALK switch (more information on page 5) Look & Listen Display™ The display shows level, channel, battery status, PROGRAM mode, whether a channel is locked, and whether a channel is locked out from selection (PROGRAM mode). See close-up on page 6. Power Switch Press PWR switch to turn unit on. Press and hold to turn unit off.
Mic Sensitivity Switch Battery Select Switch LT-700 Top of Unit SQ Switch Quick Reference Quick Reference LT-700 Inside Access Door MUTE / TALK switch - this mutes the mic only and not the line input when in the mute position. LED indicators: Steady Red: Normal operation Slow Flashing: Battery is low Slow Flashing while charging: Unit is charging Fast Flashing: Mute 3.5mm Input Jack A microphone or line level cable connects here.
Quick Reference Quick Reference LT-700 Look & Listen™ Display When dots are illuminated, the microphone is active. If this display does not appear, the microphone is muted. Indicates the unit is in PROGRAM mode (see next page). To enter PROGRAM mode, press and hold the UP and DOWN keys until the PGM icon appears in the display. To exit PROGRAM mode, let the unit sit idle for 5 seconds. Indicates the currently tuned channel Battery level indicator.
Setup Instructions LT-700 Setup Instructions Remove the product Remove outer packaging and plastic cover. Inspect for physical damage. If damage is aparent, please contact Listen Technologies Corporation technical support for assistance. See page 29 for contact information. 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.
Setup Instructions LT-700 Setup Instructions continued Set SQ switch The SQ switch is inside the battery compartment next to the Battery Select switch. The unit is shipped with SQ in the ON position. To turn it off, use a small screwdriver or pen to slide the switch to the OFF position (to the right). See page 20 for more information on SQ.
Setup Instructions LT-700 Setup Instructions continued 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. (ALK should be selected for all battery types other than NiMH). NOTE: Listen uses 1800mAh (milli-Amp-hour) constant current NiMH (Nickel Metal Hydride) batteries.
Setup Instructions LT-700 Setup Instructions continued Optional - Connect the Line Input Cable. 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 (it is 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.
Make sure the unit is on When you press the power button, the LED on top of the unit will be illuminated and the LCD display will be visible. Operating Instructions LT-700 Operating Instructions Select the channel for transmitting Please refer to Channel Selection on pages 18-19 for guidelines on choosing an interferencefree channel. To select a channel, press either the channel UP or DOWN button until the display reads the channel you want.
Operating Instructions LT-700 Operating Instructions continued Close the Access Door Lock it if desired by turning the locks on the side of the unit to the vertical position. See diagram on page 7. Using the red MUTE / TALK switch on top of the unit The red mute/talk switch on top of the unit is a handy way to “turn off” the audio from the microphone. 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 flashes rapidly.
Programming LT-700 Programming Instructions 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), and you don’t want them to have to scroll through all of the available channels, this feature is ideal. You can set up the LT-700 so that only the channels they need to use are available for selection with the UP and DOWN buttons.
Charging Batteries LT-700 Charging Batteries The LT-700 and all Listen receivers are unique because they have SmartCharge™ chargers built in. When any of these units are connected to an LA-202 wall transformer or dropped into a Listen charging case, NiMH batteries will be charged. To charge the batteries using the LA-202 wall transformer, plug the transformer into the jack marked “PWR/CHG” on the side of the unit. The unit can be operated while the batteries are charging.
During the charge cycle, the red LED on top of the Listen product will flash 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. Charging Batteries LT-700 Charging Batteries continued When not using the LT-700, it is recommended to leave the unit on the charger.
Wall Transformer Operation LT-700 Wall Transformer Operation The LT-700 will operate normally when connected to a wall transformer. Use Listen part number LA-202, available from any Listen dealer. Connect the wall transformer to the jack on the side of the LT-700 marked “PWR/CHG” and plug the wall transformer into a grounded AC outlet. You do not need to have batteries installed in the LT-700 to operate it with a wall transformer.
Channel Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Listen SQ™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 RF Reception Maximization Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 72 MHz Frequency Compatibility Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Channel Selection Channel Selection 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 72MHz and channels that start with a “2” for 216MHz when using a Listen receiver). Listen to the audio through the headphone or on a Listen receiver or receiver / speaker. Choose a channel with the least amount of interface.
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 LT-800, press both the UP and DOWN buttons simultaneously for 5 seconds. Repeat the process to unlock. Notes in regard to using 72MHz and 216MHz systems: Wide Band Recommendation Listen recommends that you always use a wide band channel unless you need to be compatible with existing narrow band receivers from other manufacturers.
Listen SQ™ Listen SQ™ 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, have more inherent noise compared to most sound systems. To reduce noise of our systems, Listen uses a noise reduction technology called ListenSQ™. Both the transmitter and receiver must have the SQ feature enabled to achieve the desired results. SQ is available on new Listen systems, including the system you received in this shipment.
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: a. When using your system, keep in mind that the location of both the transmitter and receiver is critical to maximizing signal strength. b. Eliminate or minimize obstructions between the transmitter and the receivers. c. Minimize the distance between the transmitter and the receivers. d.
72MHz Compatibility Chart 22 72MHz Compatibility Chart Wide band frequencies in shaded sections *Parenthesis indicate T35 and T20 narrowband. Frequency MHz 72.0250 72.0500 72.0750 72.1000 72.1250 72.1500 72.1750 72.2000 72.2250 72.2500 72.2750 72.3000 72.3250 72.3500 72.3750 72.4000 72.4250 72.4500 72.4750 72.5000 72.5250 72.5500 72.5750 72.6000 72.6250 72.6500 72.6750 72.7000 72.7250 72.7500 72.7750 72.8000 72.8250 72.8500 72.8750 72.9000 72.9250 72.9500 72.
Wide band frequencies in shaded sections *Parenthesis indicate T35 and T20 narrowband. Frequency MHz 74.6250 74.6500 74.6750 74.7000 74.7250 74.7500 74.7750 75.2250 75.2500 75.2750 75.3000 75.3250 75.3500 75.3750 75.4000 75.4250 75.4500 75.4750 75.5000 75.5250 75.5500 75.5750 75.6000 75.6250 75.6500 75.6750 75.7000 75.7250 75.7500 75.7750 75.8000 75.8250 75.8500 75.8750 75.9000 75.9250 75.9500 75.
216MHz Compatibility Chart 216MHz Compatibility Chart Wide band frequencies in shaded sections Frequency MHz Listen 216.0125 216.0250 216.0375 216.0625 216.0750 216.0875 216.1125 216.1250 216.1375 216.1625 216.1750 216.1875 216.2125 216.2250 216.2375 216.2625 216.2750 216.2875 216.3125 216.3250 216.3375 216.3625 216.3750 216.3875 1A 2A 3A 1B 2B 3B 1C 2C 3C 1D 2D 3D 1E 2E 3E 1F 2F 3F 1G 2G 3G 1H 2H 3H 216.4125 216.4250 216.4375 216.5125 216.
Frequency MHz 216.5375 216.5625 216.5750 216.5875 216.6125 216.6250 216.6375 216.6625 216.6750 216.6875 216.7125 216.7250 216.7375 216.7625 216.7750 216.7875 216.8125 216.8250 216.8375 216.8625 216.8750 216.8875 216.9125 216.9250 216.9375 216.9625 216.9750 216.
Troubleshooting LT-700 Troubleshooting The LT-700 has no power Make sure the unit has fully charged batteries, or has a Listen LA-202 wall transformer connected to it. Press the ON 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 in to the input jack.
The audio doesn’t have much fidelity Troubleshooting LT-700 Troubleshooting continued If your receivers all have SQ capability, activate SQ in all units by moving their switches to the ON position. In the LT-700 and all SQ-equipped receivers, the SQ switch is located inside the battery compartment. See page 20 for more information. 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.
Troubleshooting LT-700 Troubleshooting continued There is not sufficient range The LT-700 is a portable transmitter that uses the microphone cable as an antenna and the range will vary depending on the location of the receivers compared to the transmitter. You can only expect about 100 feet of average effective working range. It’s confusing for users to have 57 channels when switching between channels Use the PROGRAM function to lock out unwanted channels.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) These devices may not cause harmful interference, and (2) these devices must accept any interference received, including interference that may cause undesirable operation. Compliance Notice Compliance Notice Listen’s LT-700 Transmitter (216MHz only) Listen’s LT-700 transmitter is authorized by rule under the Low Power Radio Service (47 C.F.R.
FCC Statement FCC Statement This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
Warranty Warranty Listen Technologies Corporation (Listen®) warrants the LT-700 Portable Transmiter 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. 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 within 90 days of purchase.
Optional Accessories 32 Optional Accessories LT-700 Microphones Lavalier Over-the-Ear Conference Hand Held LA-261 LA-268 LA-277 LA-274 Over-the-Head Collar Noise Canceling LA-262 LA-276 LA-270
Optional Accessories Optional Accessories Microphones with Active Earphones Over-the-Head Mic with Earphone Over-the-Ear Mic with Earphone LA-272 LA-273 Use Both an Audio Source and Mic Line/Microphone “Y” Cable These headsets combine cabling for both a transmitter and a receiver LA-263 33
34 Notes
Notes 35
Listen Technologies Corporation 8535 South 700 West, Suite A Sandy, Utah 84070-2515 USA Telephone: +1.801.233.8992 Toll Free (North America): 1.800.330.0891 Fax: +1.801.233.8995 E-mail: info@ListenTech.
