If you are trying to add your own radio into what could be construed as a "safety of the public" system, please do not, unless you know what you are doing otherwise it could come to bite you in the arrse.. Not trying to be a spoilsport but if something were to happen and an unauthorised ra...
When you get a programmable radio you first of all 'Read' the radio contents and save them as a file so that if it all goes wrong you can reload the original read contents back into the radio..