Modifying a stock Vertex MD-12A8J or MD-11A8J for use on an Anytone AT-5888UV

I was able to purchase three desk microphones on Ebay for $15.00 each.  Two were Vertex MD-12A8J's.  The Ebay add did not specify a model and I though there were probably universal for Vertex radios with modular microphone connectors.  Assuming can sure cause problems!  These desk microphone were designed to be used on the Vertex-Standard repeaters and their wiring was different from their mobile radios. Of course, I knew I would have to rewire them when I purchased them for the radios I planned to use them on but what I did not know was there is a almost no information on the microphones on the internet and of course Vertex-Standard is now owned by Motorola, who as a company is not very forth coming in making information available upon request.  After a lot of searching, I finally hit on a discussion on the MD-11A8J which was the older model.  The only differences I could fine were a nicer looking housing for the mic.  The discussion listed the color codes of the mic cord and some continuity testing clarified the wires I neded to be able to use it on my Anytone AT-5888UV. There is a microphone gain pot on the bottom of the microphone for adjusting the internal mic preamp.  I was not able to locate and actual schematic diagram of the microphone.

I found it neccessary, using on the air testing showed that, with 5vdc from the AT-5888UV, the amplifier had to be turned up all the way.  It normally wants 9v DC.  Reports receives were that the microphone has a better sound and crisper audio than the Anytone hand microphone from a distance of about 2 feet.

Color Codes of mike wiring:

Blue:  Hook Switch which is not used in the MD-12A8J   

Braid/shield:   around white Mic High wire                           Pins 1 and/or 4 of the AT-5888UV mike connector

Brown:            PTT                                                             Pin 2 on mic connector

White:            Mic High                                                        Pin 3 on mic connector

Red:               5 to 9 vDC from radio to Mic amplifier            Pin 7 on mic connector