As has been said District police dispatch and Fire, medic dispatch are in the clear but Philadelphia does have encrypted channels that they use, even on the fire department.
Also as has been mentioned and listed, it is a phase one simulcast system that is very vulnerable to simulcast distortion. Your best radio is the SDS 100 or 200 which work very well, I agree that reception outside of the city can be poor but in my case reception does work up the Route 13 corridor into Bucks County and with a Motorola radio I can easily pick it up in Trenton, however in Montgomery County and Northern bucks and other areas it does die off as soon as you get out of the city.
This is all been covered very well in this thread. Just reinforcing what's been said.
The Citywide frequencies are in the clear such as J-band which is Administration, and certain city-wide Police Services. You will hear Citywide Flash information no matter what district it is in. The T band is your Highway Patrol and traffic units.
