100 Schematic: Yaesu Md
Radio (RJ-12) | Pin 1 (5V) ----+----> [C1 10uF] ---> [78L05 Reg] ---> +5V to Electret | Pin 6 (GND) ---+--------------------------+----------> GND for Electret | Pin 2 (MIC) <-----------------------------+----<----- [C2 1uF] <--- Electret Output | Pin 4 (UP) ----[ Switch ]-----------------+ Pin 5 (DOWN) --[ Switch ]-----------------+
increases this to 300 Hz to improve clarity in noisy conditions. High Emphasis Switch Yaesu Md 100 Schematic
Many brilliant hams have traced the PCB and drawn their own schematics. These are often clearer than the factory originals. Look for PDFs titled "Yaesu MD-100 Preamp Mod Schematic" or "MD-100 to Elecraft K3 Wiring Diagram." Radio (RJ-12) | Pin 1 (5V) ----+----> [C1