I am wondering what features i need on a scanner. I live in NYC but will mostly be using it in the Suffolk County, NY. I think that i need trunk tracking but i have seens differnt numbers of trunktracking and don't know what i need. Do i need digital. 155.58000 159.15000 KEB705 RM 146.2 PL 6 Police 6th Precinct (Corum) this is an example of one of the frequencies i will be trying to listen to.