Microphone Connections answers virtually any microphone question.http://ed.ref93.free.fr/effets/micros%20RA.pdf
Yaesu MD-1C schematic/wiringhttp://www.qsl.net/g4wpw/md1c.html
Both of mine have 3 wires in the cable going to the radio. What are the odds they both would be changed. And why. These came from 2 different parties. Just seems odd. Mike
Depends on who was selling the microphones (when new) ... some CB shops set up "mod operations" to sell amateur equipment to the freeband/pirate radio crowd.