DEAR TOM: I DO NOT HAVE THE INFO YOU WANT TO MODIFY THE MLA-2500 BUT I HAVE A MLA- 2500 UNIT AND I DO WANT TO MODIFY IT. SO, IF YOU GET THE INFO ON THE 400 MOD. I SURE WOULD LIKE A COPY OF IT. MY FAX IS (716) 433-1099. BEST REGARDS & THANK YOU FRED (DUANE FREDERICKS) K2GKM