The complete schematic for the Yaesu MD-100/100A8X Go to product viewer dialog for this item.
The mic uses operational amplifiers (often listed as μPC4572Cmu cap P cap C 4572 cap C
Understanding the Yaesu MD-100 Schematic and Technical Design
covers the microphone head, the active filtering circuitry in the base, and the output wiring for both 8-pin round and modular (RJ-45) connectors. Key Circuit Sections
: Adds a +6 dB boost at 3000 Hz, designed to provide "DX punch" by emphasizing speech frequencies that cut through interference. Interface and Pinout Structure