The 508.1875 frequency elias listed is the County Fire Dispatch frequency. County does all dispatching for Jackson fire. After county tones them out, communicatons between county and the fire units are on the Jackson Fire Tac 1 frequency listed in the database here (the link that elias provided in his post). They rarely use the Fire Tac 2 frequency. The Fire Ground A, B, & C frequencies are low power, so you would have to be near the scene of the incident in order to hear them on any of those frequencies.