• Noise Cancellation

  • The 38T cancels noise best when held very close to the mouth, and it discriminates against all sounds more than ½-inch away. A position at one side of the mouth is best to minimize popping, hissing and breathing sounds when speaking.
  • Microphone Gain Adjustment

  • The gain is adjustable through an opening in the side of the microphone housing using a small, flat-blade screwdriver. Clockwise rotation of the control increases gain. Adjustment by a qualified avionics technician is recommended, as excessive gain can cause transmitter overload distortion.
  • FAA TSO Approval

  • The 38T microphone is certified for aviation use under FAA TSO C58.


Microphone Sensitivity -45 - -51 dB (re: 1 V / μbar @ 1 kHz, 12 VDC)
FAA TSO Approvals C-58
Retracted ~11.5 in (292 mm)

Extended ~6 ft. (1.8 m)
Weight ~8 oz (227 g)
Microphone Type Close Talking Differential, Electret Element
Mounting External Diameter Mount
Frequency Response 300 Hz – 3 kHz
Connector Type PJ-068 or XLR-4-12C
Warranty 3 years


Name Size Date
38T EC Declaration of Conformity 101KB Nov 6, 2014
38T FAA TSO Approval 56KB Nov 6, 2014
Name Language Size Date
38T Technical Data Sheet EN 277KB Nov 6, 2014

38T Mic

38T Full

38T Speaker Close

Name Language Size Date
Maintenance & Overhaul Manual Publication Index EN 74KB Jan 4, 2021
Name Size Date
Headset Cleaning Memo 84KB Jun 12, 2020
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