Justy -
The NCHP patrol units in Johnston should be transmitting on 42.86 MHz when talking with Raleigh.
Raleigh dispatches to the cars on 42.82 MHz.
Your reception of the NCHP cars will be limited, unless you are using an external antenna designed for low band reception.
Some of the districts Raleigh works have recently changed channels, but not Johnston County (district 6), according to a previous thread on RadioReference.
Other channels I would monitor include:
- 42.22 ... NCHP channel 19, used for car-to-car and special events communications
- 154.680 ... the high band repeater (if still used in your area)