IT IS ON PPM MODE LIKE YOU SAID BUT SOME ONE AT OUR LOCAL HOBBY SHOP TOLD ME THAT SINCE THE RADIO IS A PCM THAT THE CRYSTAL IN THE MODULE WOULD ONLY WORK ON PCM RECEIVERS AND I MIGHT HAVE TO PUT A REGULAR DUAL CONVERSION CRYSTAL IN THE MODULE TO MAKE IT WORK? IS THIS TRUE? LIKE I SAID BEFORE ON ONE SIDE OF THE CRYSTAL IT HAS A (TYPE 72-7) AND THE OTHER SAYS (TYPE 72-10) DOES THIS MATTER ARE BOTH YOUR CRYSTALS READING THE SAME #? THANKS FOR YOU TIME AND HELP!! RICHARD JAMES