The MD-100 typically uses an 8-pin round connector or an RJ-45 modular plug for connection to Yaesu transceivers. RigPix Database Wire Color Description Scanning control: Up / Fast speed Power for active filtering circuits Scanning control: Down Scanning control: Fast speed toggle Chassis and logic ground Push-To-Talk control Mic Ground Dedicated audio return ground Microphone audio signal output Circuit Overview
Most connection issues happen at the plug. If you're building a patch cable or repairing the original, here is the standard 8-pin wiring color code for the MD-100: Typical Wire Color 2 3 DOWN (Scan) 4 FAST (Scan) 5 6 PTT (Push-to-Talk) 7 Mic Ground (Shield) Shield/Clear 8 2. Technical Schematics & Diagrams Yaesu Md 100 Schematic
Understanding the schematic requires understanding the pinout of the 8-pin connector (RJ-45 or Round DIN depending on the adapter used). The MD-100 typically uses an 8-pin round connector