Zaxcom TRX743


The TRX743 is a wide-band plug-on style digital wireless transmitter with interchangeable cones, it’s the only plug-on transmitter that supports all professional microphone varieties – mono analog, stereo analog, AES and AES42 – making it an ideal choice for wireless transmission directly from boom poles or handheld microphones.

Its body is constructed from a combination of high strength nylon polymer and aluminum. It features Zaxcom High Density (ZHD) Modulation.

SKU: zc009 Category:


The TRX743’s cones are easily swapped in the field for ultimate flexibility. It comes standard with one cone of your choice, extra cones can be purchased seperately.

Cone choices:
Mono Analog – 3-Pin XLR
Stereo Analog – 5-Pin XLR
AES (not powered) – 3-Pin XLR
AES42 (powered) – 3-Pin XLR


The TRX743 transmits using 100% digital modulation allowing audio to be fully encrypted. Digital encryption is the only way to keep all audio transmission private. A digital transmission also provides audio quality superior to analog systems.


The TRX743 also sends a Quality Control audio signal over ZaxNet™, so when micing someone you don’t have to go all the way to the cart to hear how it sounds, you can use an ERX to listen to the mic right on the spot.


NeverClip™ is a standard feature of the TRX743 and works with all mono transmission types. It works by utilizing two A-D converters to extend the dynamic range of the transmitter to 126 dB, so there’s never any limiter distortion.


Audio is simultaneously transmitted and recorded to a removable microSD card using the highly reliable MARF (Mobile Audio Recording Format) which eliminates file corruption common to recordings due to a dead battery or early card removal.


TRX743 is equipped with ZaxNet™, a long-range remote-control system allowing the user to change the frequency, pre-amp gain, sleep mode, and place the internal recorder in record, playback, and stop modes – all without ever needing to disturb talent.

The units can also replay audio via a timecode reference, giving production sound mixers the ability to replay and remix audio, creating a virtual multi-track playback and re-record system.


To extend battery life, PowerRoll™ adjusts the TRX743’s power level to 100mW when the audio received from it is being recorded by a ZaxNet™ compatible recorder. When the transmitter audio isn’t being recorded the power is automatically reduced to 25mW.


The range will always vary depending on your environment, but you’ve got choices to optimize transmission for peak performance. Zaxcom High Density modulation (ZHD) increases the number of available channels from 4 to 9 for every 1 MHz of spectrum space, perfect for reflective environments like busy city streets. XR gives you the maximum distance in less dense / more controlled spaces.


The TRX743 runs on 3 x AA battery cells, the runtime is completely dependent on battery type and the power requirements of the microphone you’re using.


TRX743 is available in the following frequency bands:
“.5 band” (512-608 MHz)
“.6 band” (578-698 MHz) (not available in the U.S.)

Zaxcom Digital Recording Wireless Transmitters are protected under patent #’s: 7,711,443 & 7,929,902


  • Transmitter
    • RF ModulationProprietary Digital Method
    • TRX743.5 RF Frequency Range512 – 614 MHz
    • TRX743.6 RF Frequency Range596 – 698 MHz
    • RF Frequency Step100 KHz
    • RF Bandwidth in ZHD Mode50 KHz
    • RF Bandwidth in XR Mode200 KHz
    • Channel Separation in ZHD Modeas close as 100 KHz (receiver dependent)
    • Channel Separation in XR Mode400 KHz
    • Antenna Connector50 Ω SMA Female
    • Emission Designator180 KV2E, 100 KV2E, 50 KV2E
    • FCC Part74.861
  • Transmitter Audio
    • Dynamic Range126 dB (Stereo model 106 dB)
    • Distortion0.002%
    • Frequency ResponseMode 0
    • High Pass FilterOff or 30 to 220 Hz, Steps
    • Mic Connector3-Pin or 5-Pin XLR
    • Analog Mic Power48 V Phantom (10 mA max)
    • Digital Mic Power10 V AES42 compatible (200 mA max)
    • Input Range-60 to -30 dBu
    • Mic Impedance4.7 k Ω
    • ADC Bit-Depth24 Bits
    • Audio InterfacesBalanced analog mono, balanced stereo, AES42, AES
  • Timecode Reader / Generator
    • Clock Accuracy1.54 PPM (1 Frame Out in 6 Hours)
    • Timecode TypeSMPTE
    • Timecode Frame-Rates23.98, 24, 25, 29.97NDF, 29.97DF, 30NDF, 30DF
  • Internal Recording
    • MediaMicroSD Card (Flash Memory)
    • File Format.ZAX
    • Recording Time
  • 2.4 GHz ZaxNet Receiver
    • RF Frequency Range2.403 to 2.475 GHz
    • RF ModulationDigital Spread Spectrum
    • RF Frequency Step0.001 GHz (1 MHz)
    • RF Bandwidth1 MHz
    • Channel Separation2 MHz
    • Sensitivity-96 dBm
  • Physical
    • Weight7.5 oz with Battery
    • Dimensions (H x W x D)5 cm x 11.5 cm x 4 cm
    • DisplayGraphic OLED
  • Power
    • Power Output25, 50 or 100 mW – Software Selectable
    • Battery Type3 AA cells
    • Battery LifeBattery Type / Mic power requirement dependent