The 602T is a handheld dynamic microphone designed for highly articulate speech transmission under high ambient noise. The 602T is the result of a continuous study of the need of the communications industry so that it uniquely meets the specialized requirements of airline, two-way radio, and industrial applications. The 602T is a transistorized, pressure-gradient microphone utilizing three sound entrances for reduction of interfacing ambient noise. Stated simply, if sound pressure and phase are reasonably identical at all three sound entrances, as in the case of relatively distant sounds, then little or no output results. The 602T is unexcelled at discriminating between near and distant sounds for maximum ambient noise rejection. The compact single-stage transistor amplifier is specially stabilized and will operate uniformly from -20°C to +55°C. Output of the transistor amplifier is designed for carbon microphones. A screwdriver accessible potentiometer is provided for adjustment of output level.