I have a Yaesu MD-100A8X Desktop Mic , I'd like to use it on my Yaesu FT-757GX II ? I bought a cord on ebay that was suppose to be able to match the mic to the radio , there's keyup but no audio . Has anyone else ever put an MD-100A8X on a FT-757GX II , how difficult would it be for me to get them to match up and work right together ?