TM400 Test and Measurement Wireless System

Block A1 (470.100 - 537.575 MHz)


  • System does not include microphone
  • Replaces long cable between calibrated microphone and test equipment
  • 24-bit, 88.2 kHz digital signal handling for compandor-free audio
  • 256 synthesized UHF frequencies for wide choice of tunings to avoid interference
  • Rugged all-metal construction
  • R400a Receiver:
    • Low noise, robust RF front end
    • Balanced XLR audio output
    • SmartTuning™ with graphic display for easy selection of clear RF frequencies
  • HMa Transmitter:
    • Converts microphones with XLR jacks to wireless operation
    • Selectable 5, 18, 48 Volt powering
    • 100 mW RF output power for long range
    • Membrane switch control panel with LCD display

Consumer Alert

Starting in 2017, the 617-652 MHz and 663-698 MHz frequencies are being transitioned by the Federal Communications Commission (FCC). Users of wireless microphone devices that operate in any portion of those frequencies must cease operating on these frequencies no later than July 13, 2020. In addition, users of this device may be required to cease operations earlier than that date if their operations could cause harmful interference to a 600 MHz service licensee’s wireless operations on these frequencies. For more information, visit the FCC’s wireless microphone website at or call the FCC at 1-888-CALL-FCC (TTY: 1-888-TELL-FCC).

Most users do not need a license to operate this wireless microphone system. Nevertheless, operating this microphone system without a license is subject to certain restrictions: the system may not cause harmful interference; it must operate at a low power level (not in excess of 50 milliwatts); and it has no protection from interference received from any other device.