I don't really want to dash too many hopes here but if you're talking about the Baltimore county P25 system (it's VERY important to be specific), you might as well forget it. The 396 does not deal very well with the new LSM modulation that this system uses; any bit of overloading or multipath problems and you won't decode anything at all. I also have a 396 and work in the Woodlawn area. The XTs seem to do a better job with this.
In more general terms, you should get a
premium subscription and download the new freqs from the database. However if you want to do this manually, set up a new system as a
Mot Type II/P25, and the site (really isn't a site, because a 396 cannot do multi site) form should be set up as
Mot 800 Standard Type II. I use FreeScan for my programming, as its freeware.
According to the latest intel, the analog system is on standby as a fallback in case the P25 system runs into issues, so I wouldn't delete the analog system just yet.
You can find a full discussion on the issues in the Maryland forum here...
http://forums.radioreference.com/ma.../219410-new-baltimore-county-p-25-system.html
and here is our wiki article on the subject...
Baltimore County P25 - the RR Wiki
Don't fall into the trap of just reading new entries - read all the entries. Become familiar with all the forums we have here.
HTH Mike