Stationary FM Transmitter (150 MHz)
LT-800-150
Highlights
- Superior Audio Quality – 80 dB signal-to-noise ratio, setting the industry’s sound quality standard.
- With a choice between 32 channels, Listen products are ideal for a wide range of applications.
- 100 % Digital – Listen receivers are digitally-tuned so transmission won’t drift; assurance that when a channel is selected, it stays on that channel.
- Up to six (6) simultaneous transmitted channels.
- Look & Listen™ LCD shows channel, channel lock, and programming information.
- Balanced/Unbalanced Inputs – user can interface with any audio source on the market.
- Designed for installation – rack mountable with optional remote antennas make installation easy and service reliable.
- Limited Lifetime Warranty .
- Auto Processor – to condition the audio for voice/music prior to transmission.
- VU level meter and test tone – simply makes the installation easier to set-up.
- 30-day no obligation demonstrations available.
- Many accessory options make Listen products ideal for a wide range of applications.
Overview
Thanks to its outstanding audio quality, the Listen LT-800-150 Stationary FM Transmitter can be used in a variety of applications. The LT-800-150 is excellent for assistive listening, language interpretation, or other applications where running cable may not be an option. This transmitter is a great choice for interfacing to an existing sound system and broadcasting the desired sound throughout a venue. The LT-800-150 offers versatility with many different types input connections; line or mic level, balanced, unbalanced. It can be rack mounted with our optional universal rack mount kit or can be placed on a shelf. The LT-800-150 offers 32 frequencies for easy set up for a clear interference free channel. The end result – the audience can hear and understand the presentation.
Note: for use in Australia
Includes
Architectural Specs
The stationary FM transmitter shall be capable of broadcasting on 32 channels. The transmitter shall have an SNR of 80 dB or greater. The output power shall be adjustable to quarter, half or full. Channel tuning shall be capable of being locked. The device shall have an audio frequency response of 50 Hz to 15 kHz (±3 dB). It shall have two (2) mixing audio inputs and a mixed signal output. The device shall have the following audio controls: input level, mix level and an adjustable low pass filter (contour). The device shall have an audio processor that is capable of automatic gain control and limiting. The Listen LT-800-150 is specified.
Line Drawing

- POWER on/off on front of unit for easy access.
NOTE: For more detailed Line Drawing see LT-800 Datasheet under "Support Info" tab.
Specifications
| Specifications | LT-800-150 | |
| Audio | RF Frequency Range | 150.8000 MHz - 152.3500 MHz |
| Number of Channels | 6 wideband, 26 narrowband | |
| Number of Simultaneous Transmitters | 6 | |
| Frequency Accuracy | ± .005% stability 32 to 122º (0 to 50ºC) | |
| Transmitter Stability | 50 PPM | |
| Transmission Range | Up to 762 m (2500 ft.) | |
| Output Power | 100 mW | |
| Antenna | Various | |
| Antenna Connector | BNC | |
| Compliance | CE, ETSI, RoHS | |
| System Frequency Response | 50 Hz - 15 kHz (±3 dB) | |
| System Signal to Noise Ratio | SQ enabled 80 dB, SQ disabled 60 dB | |
| System Distortion | <2% total harmonic distortion (THD) at 80% deviation | |
| Audio Input 1 | Rear panel, one (1) Female XLR and 1/4 in combo connector, balanced, 0 / -55 dBu (line/mic) nominal input level adjustable, -30 / +21 dBu (line/mic) maximum input level, impedance 20k / 1k ohms (line/mic), phantom power +12 VDC | |
| Audio Input 2 | Rear panel, two (2) phono connectors, unbalanced, -10 / +10 dBu nominal input level adjustable, +30 dBu maximum, impedance 100k ohms | |
| Audio Processing (Process) | Compression can be turned on/off. Slope internally adjustable from 1:1 to 4:1. Default 2:1 | |
| Contour | Cuts and boosts frequencies above 5 kHz | |
| Combined Audio Output (Mix) | Input 1 and input 2, mixed output (rear panel), two (2) phono connectors, unbalanced, -10 dBu nominal output level, +15 dBu maximum, impedance 10 ohms | |
| Headphone Output (Monitor) | Front panel, one (1) 3.5 mm (0.14 in.) stereo connector, unbalanced, adjustable output level, +3 dBu maximum, impedance 10 ohms | |
| Controls & Indicators | Front Panel | Power, Test Tone on/off, Channel up/down, Input Levels, Mix Level, Contour, Monitor volume control |
| Rear Panel | Input 1 Level, (Line, Mic, Mic-Phantom Power), Input 2 level (-10 / +10 dBu), RF power level (low, mid, high) | |
| Internal Adjustments | Compression ratio for audio processor | |
| Programming | Process on/off, SQ on/off, channel lock | |
| Input1, Input 2, Mix Level VU | Indicates Input 1, Input 2, and Mix audio levels; 10 segment LED's (8 green, 2 red) | |
| Processing | Indicated by a green LED when on (front panel) | |
| RF Power | Indicated on the LCD (low, mid, high) | |
| LCD Display | Channel Designation, lock status, RF power level, programming (front panel) | |
| Test Tone | Red LED illuminates when test tone is enabled. | |
| Power | Power Supply | In line power supply (Listen part number LA-207) |
| Power Supply Input | Input: 100-240 VAC, 50-60 Hz, 0.4 A | |
| Power Supply Output | Output: 12 VDC, 1.3 A, 15.6 W | |
| Power Supply Connector | Output Connector: 0.02 in (5.0 mm) OD, 0.01 in. (2.5 mm) ID, barrel type | |
| Power Supply Compliance | UL, CE, GS, TÜV, RoHS | |
| Physical | Dimensions (H x W x D) | 1.75 x 8.50 x 9.13 in (4.5 x 21.5 x 23 cm) |
| Color | Dark Grey with white silk screening | |
| Unit Weight | 2.6 lbs. (1.2 kg) | |
| Unit Weight with LA-207-03 Power Supply | 3.5 lbs. (1.6 kg) | |
| Shipping Weight | 6 lbs. (2.7 kg) | |
| Rack Mounting | One (1) rack space height, 1/2 rack space wide. One (1) or two (2) transmitters can be mounted in one rack space, optional rack mount (LA-326) | |
| Compliance | ||
| Environmental | Temperature - Operation | -10 ºC (14 ºF) to +40 ºC (104 ºF) |
| Temperature - Storage | -20 ºC (-4 ºF) to +50 ºC (122 ºF) | |
| Humidity | 0 to 95% relative humidity, non condensing | |
| Specifications are subject to change without notification | ||
Used With
-
LR-500-150 Portable Programmable Display FM Receiver (150 MHz)
The most advanced of Listen’s portable receivers, the LR-500-150 Programmable Display Receiver can be programmed so users can only tune to desired channels.
Note: for use in Australia -
LR-400-150 Portable Display FM Receiver (150 MHz)
The LR-400-150 Portable Display FM Receiver is our most popular model of receiver.
Note: for use in Australia
Accessories
-
LA-207 12 VDC Replacement Power Supply for LT-800
The power supply is used to power the LT-800 Stationary Transmitter.
-
LA-304 Assistive Listening Notification Signage Kit
An important part of the American’s with Disabilities Act compliance policy is signage to identify the availability of auditory assistance equipment. Listen provides a simple kit to meet these needs.
-
LA-326 Universal Rack Mounting Kit
This kit is for mounting the LT-800 Stationary Transmitter or the LR-100 Stationary Receiver/Amplifier.
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LA-390 RG-8 50 Ohm Preassembled Coaxial Cable (Per ft.)
Gives the right amount of cable for your FM/IR predesigned system.
-
LA-391 RG-58 50 Ohm Preassembled Coaxial Cable (Per ft.)
Gives the right amount of cable for your FM/IR predesigned system.
-
LA-82 6-Way RF Antenna Combiner
A passive device (no power supply needed) that takes six (6) incoming RF signals and combines them into one (1) outgoing antenna source.
-
LA-81 4-Way RF Antenna Combiner
A passive device (no power supply needed) that takes four (4) incoming RF signals and combines them into one (1) outgoing antenna source.
-
LA-80 2-Way RF Antenna Combiner
A passive device (no power supply needed) that takes two (2) incoming RF signals and combines them into one (1) outgoing antenna source.
Support Documents
FAQ
No, but an LA-326 Universal Rack Mounting Kit is available for purchase.
Yes.
Up to 762 m (2,500 ft.)
Yes. There can be up six (6) simultaneous channels with 150 MHz.
As many as wanted. The transmitter simply transmits a signal and you can have as many receivers pick that signal up as necessary. It’s like a radio station transmitting and the receivers are the radios tuning into the “channel.”
Troubleshooting Guide
What is the range of this transmitter?
- Depends on the following:
- The frequency of the transmitter.
- The transmitter's location.
- The antenna being used on the transmitter and receiver.
- The location of the remote antenna (if applicable). In general, the higher the antenna the more range.
- The length of coaxial cable ran to the antenna from the transmitter (if applicable). Every foot of cable creates a power loss.
- The RF power setting on the transmitter.
- The objects between the transmitter and receiver. All material, especially metal, will weaken the signal strength.
- When using 72 MHz, a direct line of sight distance of 1500 feet from the transmitter can be achieved.
- When using 216 MHz, a direct line of sight distance of 3000 feet from the transmitter can be achieved.
What channels should I be transmitting on?
- It is recommended that wideband channels are used for best audio quality. If transmitting multiple simultaneous channels, narrowband frequencies may be required.
How many transmitters can I have operating simultaneously?
- 72 MHz: 6 simultaneous transmissions
- 216 MHz: 3 simultaneous transmissions
The signal being transmitted is inconsistent, my receiver cuts in and out.
- The receiver may be out of range of the transmitter.
What type of microphones can I use with this transmitter?
- Dynamic microphones can be used when the Input 1 level select switch is in the "MIC" position.
- Condenser microphones can be used when the Input 1 level select switch is in the "MIC + Phantom Power" position.
I can't change the channel on my transmitter.
- The unit is locked on a channel. To unlock, hold the channel select "Up" for 3 seconds. The padlock icon will extinguish from the LCD display.
I can't access the narrowband channels on my transmitter.
- The transmitter is in "Basic mode" and all narrowband channels are locked out. To enter "Expanded mode" and transmit on a narrowband channel, hold the channel select "Down" button while turning on the unit.
What does the "contour" knob do?
- The contour knob boosts or cuts frequencies above 5kHz. It is recommended that this knob be turned counterclockwise for voice and clockwise for music.
What does the "process" feature do? When should I use it?
- The process feature is a type of Automatic Gain Control. If your input signals to the transmitter are inconsistent in level and you wish to have gain control, then this should be turned on.
Where should I have the input level switches positioned on the back of my transmitter?
- Depends on the level of audio being input.
- When using Input 1:
- MIC position: For a microphone or MIC level input of -55dbu.
- MIC Phantom Power: For a condenser microphone that needs a 12VDC phantom power supply supply at a -55dbu level input.
- When using Input 2:
- +10dbu/SPKR position: When connecting a speaker or any other higher line level audio input.
- -10dbu/Line position: When connecting a regular line level input of -10dbu.
My transmitter seems to have lost power/range.
- Make sure that the antenna is connected properly.
- Make sure that the RF power switch is in the correct position.
- A more efficient transmit antenna may be needed.
Can this transmitter be powered with a DC voltage?
- NO. The transmitter must use the supplied 15VAC power supply.
Can I use this transmitter with other manufacturer's receivers?
YES. Please refer to the frequency compatibility charts in the manual or on the website for channel conversions. When using other manufacturers products, SQ (Super Quiet) must be turned OFF.