David Clark M-1/DC Amplified Dynamic Microphone | 12948G-14 This M-1/DC microphone has a screwdriver-adjustable gain control so you can easily adjust to different modulation levels. The M-1/DC will not operate in circuits that do not supply a DC bias voltage. While this type of voltage is supplied by most modern aviation communications equipment, consult your radio technical manual or avionics shop for more information. Old Part Number 12948G-01
