BlackMax Transmitter Module

Audio Transmitter

The DRTXM4 Synchronized Audio Transmitter is the highest-efficiency HAR transmitter manufactured. It produces a strong signal to broadcast your highway advisory messages at the maximum legal power allowed by the FCC. Comprehensive metering is clearly displayed on the front panel to indicate the transmitter is performing. 

The DRTXM4 Synchronized Audio Transmitter is power adjustable to use the full 10W allowed by FCC and can be adjusted from 0-10W by an adjustment knob located on the side of the transmitter. When used in conjunction with the TCM-1 amplifier module, output wattage of up to 30W can be attained. 

Quick Facts

  • Capable of 100% modulation
  • Modular design provides easy access and maintenance
  • Front-panel status indicators provide quick visual feedback on transmitter status



  • Front panel power switch and RF output connector.
  • Overload mismatch output protection
  • 5 level LED modulation display

Technical Specifications

Interface, Port Data

RF Output 0 to 10W as allowed by FCC
Audio Distortion <1.5% from 200Hz to 3.5kHz
Frequency 530 to 1700 khz
Modulation 100% • Speech limiter controls
Audio Response Better than ± 1 dB • Better than 20 dB down at 100 Hz Better than 30 dB down at 60 Hz • Attenuation above 3 kHz conforms to FCC specifications
Inputs Normal audio input from recorder/player through backplane Auxiliary balanced, high-impedance, phone-line

Environmental Data

Dimensions 10.3” (h) x 3.2” (w) x 9.2” (d
Power Requirements 10 to 14 VDC at less than 2A
Operating Temperature -40° C to +85° C
Storage Temperature -40° C to +85° C
Humidity 20%-95% RH, non-condensing
FCC Certification O2Q-DRTMX4

Get in touch

Technical Support

US Toll-Free: (800) 380 1718
+1 (614) 873 5216

Contact MH Corbin

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