Listen Technologies LT-803-072-01 3-Channel 72 MHz RF Transmitter

Listen Technologies LT-803-072-01 3-Channel RF Transmitter (72 MHz)

The Listen Technologies LT-803-072-01 3-Channel RF Transmitter is a stationary assistive listening transmitter that broadcasts one audio program on a selectable 72 MHz channel. It accepts microphone and line-level sources, combines two audio inputs, and provides audio processing and front-panel monitoring for installed listening systems in public spaces.

Designed for houses of worship, lecture halls, theaters, and other venues, this transmitter connects existing sound systems to compatible personal listening receivers. Choose from channels A, E, or H to configure a 72 MHz assistive listening installation without requiring a separate transmitter for each listener. Its balanced XLR/1/4" combination input, stereo RCA input, and mixed RCA output accommodate common professional and consumer audio connections. The transmitter supports installations requiring reliable audio distribution for assisted listening, guided presentations, and spoken-word programming.

The front-panel Look & Listen LCD identifies the selected channel, lock status, and RF power setting, while ten-segment meters help operators monitor incoming audio levels. Automatic gain control, limiting, adjustable compression, and contour processing support speech and music reproduction. The half-rack-width chassis fits a 1U rack space with an optional mounting kit. A separately purchased 72 MHz antenna and compatible receivers complete the wireless listening system. Legacy Listen Technologies receivers must use the matching channel with SQ mode disabled.

Key Features

• Three Selectable RF Channels: Choose between 72.100 MHz, 72.900 MHz, and 75.900 MHz for single-channel assisted listening applications.
• Flexible Audio Connectivity: Balanced XLR/1/4" microphone and line input plus unbalanced RCA connections accommodate various audio sources.
• Built-In Audio Processing: Automatic gain control, limiting, adjustable compression, and contour processing help maintain consistent audio levels.
• Look & Listen LCD: Displays channel selection, channel lock status, and RF transmission power for convenient system monitoring.
• Adjustable RF Transmission Power: Select low, medium, or high output settings to accommodate different installation requirements.
• Integrated Audio Monitoring: Front-panel headphone output and LED level indicators simplify signal monitoring and troubleshooting.
• Compact Rack-Compatible Design: Half-rack-width, 1U-high chassis supports optional rack mounting with the LA-326 mounting kit.
• Compatible Receiver Support: Works with appropriately configured Listen Technologies 72 MHz receivers, allowing multiple listeners to receive the same program.

Technical Specifications

General Information

• Brand: Listen Technologies
• Model: LT-803-072-01
• Product Type: Stationary RF Assistive Listening Transmitter
• Operating Band: 72 MHz
• Application: Installed assistive listening systems
• Transmission Configuration: One channel at a time from three selectable frequencies
• Color: Dark gray with white markings

RF Transmission Specifications

• RF Channels: 3 wideband channels
• Channel A: 72.100 MHz
• Channel E: 72.900 MHz
• Channel H: 75.900 MHz
• Frequency Accuracy: +/-0.005% stability from 32 to 122 degrees F
• Transmitter Stability: 50 ppm
• Transmission Range: Up to 1,000 ft. line of sight with a remote antenna
• RF Output Power Settings: Low, medium, and high (quarter, half, and full power)
• RF Output Measurement: 80,000 microvolts at 9.8 ft.
• Antenna Connection: 50-ohm BNC
• Compatible Antennas: Optional Listen Technologies 72 MHz antennas
• Recommended Antenna Cable: RG-58 for runs under 100 ft.; RG-8 for runs over 100 ft.

Audio Performance

• Frequency Response: 50 Hz to 15 kHz (+/-3 dB)
• Signal-to-Noise Ratio: 62 dB (A-weighted)
• Total Harmonic Distortion: Less than 2% at 80% deviation
• Audio Processing: Automatic gain control, limiting, and adjustable compression
• Compression Control: Selectable on/off
• Compression Ratio: Internally adjustable from 1:1 to 4:1
• Default Compression Ratio: 2:1
• Contour Processing: Adjustable attenuation and enhancement of frequencies above 5 kHz
• Audio Mixing: Two audio inputs with adjustable mixed output

Audio Inputs

• Audio Input 1 Connector: 1 x XLR/1/4" combination connector
• Audio Input 1 Location: Rear panel
• Audio Input 1 Configuration: Balanced microphone/line input
• Audio Input 1 Nominal Level: 0 dBu line / -55 dBu microphone, adjustable
• Audio Input 1 Impedance: 20 kilohms line / 1 kilohm microphone
• Microphone Phantom Power: +12 VDC
• Audio Input 2 Connectors: 2 x RCA connectors
• Audio Input 2 Configuration: Unbalanced
• Audio Input 2 Nominal Level: -10/+10 dBu, adjustable
• Audio Input 2 Maximum Level: +30 dBu
• Audio Input 2 Impedance: 100 kilohms

Audio Outputs

• Mixed Audio Output: 2 x RCA connectors
• Mixed Output Configuration: Unbalanced
• Mixed Output Nominal Level: -10 dBu
• Mixed Output Maximum Level: +15 dBu
• Mixed Output Impedance: 10 ohms
• Headphone Output: 1 x 1/8" stereo connector
• Headphone Output Location: Front panel
• Headphone Output Configuration: Unbalanced, adjustable
• Headphone Maximum Output: +3 dBu
• Headphone Output Impedance: 10 ohms

Controls and Indicators

• Front-Panel Controls: Power, test tone, channel up/down, input levels, mix level, contour, and monitor volume
• Rear-Panel Controls: Input 1 microphone/line selection, phantom power, Input 2 level selection, and RF output power
• Internal Adjustment: Audio compression ratio
• Programmable Functions: Audio processing on/off and channel lock
• LCD Display: Channel designation, channel lock status, and RF power level
• Audio Level Monitoring: 10-segment LED indicators for Input 1, Input 2, and mixed audio
• Level Indicator Colors: 8 green and 2 red LEDs per meter
• Processing Indicator: Green LED
• Test Tone Indicator: Red LED
• RF Power Indicator: Low, medium, or high on LCD

Power Requirements

• Power Supply Model: Listen Technologies LA-207
• Power Supply Type: External in-line AC adapter
• AC Input Voltage: 100-240 VAC
• AC Input Frequency: 50-60 Hz
• AC Input Current: 0.4 A
• DC Output Voltage: 12 VDC
• DC Output Current: 1.3 A
• Power Supply Rating: 15.6 W
• Power Connector: Barrel type, approximately 0.2" outer diameter and 0.1" inner diameter

Physical Specifications

• Dimensions (L x W x H): 9.1" x 8.5" x 1.8"
• Unit Weight: 2.6 lb
• Weight with Power Supply: 4.5 lb
• Manufacturer-Specified Shipping Weight: 6 lb
• Rack Mounting: 1U height, half-rack width
• Rack Capacity: Up to two transmitters per 1U rack space using optional mounting hardware
• Compatible Rack Mount Kit: LA-326 Universal Rack Mounting Kit, sold separately

Environmental and Regulatory Specifications

• Operating Temperature: 14 to 104 degrees F
• Storage Temperature: -4 to 122 degrees F
• Relative Humidity: 0-95%, non-condensing
• Listed Certifications and Compliance: UL, CE, GS, TUV, and RoHS
• RF Regulatory Compliance: FCC Part 15, FCC Part 90, and Industry Canada

What's in the Box

• 1 x Listen Technologies LT-803-072-01 Stationary 3-Channel RF Transmitter (72 MHz)
• 1 x Power Supply
• 1 x Quick Reference Card

Installation Note: The transmitter broadcasts on only one of its three selectable channels at a time. A compatible antenna and RF receivers are required for a complete listening system and are sold separately. Rack mounting hardware is also sold separately.