This from Chris Ranck:

this from carma chicago;  NORTHWEST CENTRAL is switching to a new radio system , it will be a new STARCOM 21 system . It will be a new tdma system which is a non-monitorable radio system . They are supposed to switch on MARCH 26 2013 . They will be switching the old digital system first, towns like ELK GROVE ,  ARLINGTON HEIGHTS, BUFFALO GROVE etc……  2) SCHAUMBURG system and finally STREAMWOOD and HOFFMAN ESTATES systems.  Since it’s tdma, scanners won’t be  able to recieve it .

Tags: CARMA Chicago, Chris Ranck, new radios for Northwest Central Dispatch, Northwest Central Dispatch, Northwest Central Dispatch System, NWCD