For radio traffic on DEC 80 / HEX 50 / Dispatch-2 South, at approx. 23:00-06:00 hours you must switch over to DEC 112 / HEX 70 / Dispatch-3. The two channels South and West (Baker and Charlie Precincts) seem to be merged into two channels. I'm not 100% about the time slots but you just have to check each one. Also, dispatch/police personnel will somtimes refer to channels as Ax (how their MTS2000 radios are listed); make note of these:

A1 - North Dispatch (Alpha)
A2 - South Dispatch (Baker)
A3 - West Dispatch (Charlie)
A4 - Records Div.
A5 - Common (All Precincts)
A6 - Supervisor Channel (Designated: Unit x) (Very Rare Trans.)
A7 - North (Alpha) Common
A8 - South (Baker) Common
A9 - West (Charlie) Common

There are also channels Bx and Cx, on the MTS2000, for miscellaneous type channels. Also if your wondering about what the unit descriptions are, it works like this:

Unit "Designator" and "10-8" times

First Shift (10's; 0600-1400 / 20's; 0630-1430)
Alpha/Baker/Charlie - 11/21 (First Shift Sergeants)
Alpha/Baker/Charlie - 1x/2x; x>1 (First Shift Officers)

Second Shift (30's; 1400-2200 / 40's; 1430-2230)
Alpha/Baker/Charlie - 31/41 (Second Shift Sergeants)
Alpha/Baker/Charlie - 3x/4x; x>1 (Second Shift Officers)

Third Shift (50's; 2200-0600 / 60's; 2230-0630)
Alpha/Baker/Charlie - 51/61 (Third Shift Sergeants)
Alpha/Baker/Charlie - 5x/6x; x>1 (Third Shift Officers)