Go to the CARMA website at
http://ww.carmachicago.com/profiles and download the ARC-XT files for StarCom21. Turn off all the sites except 108, 120, 126, 146, 147 and 148 (if you use it in the house...) and make sure the radio is in Talkgroup Search mode.
As talkgroups come up for things that you are not interested in you can lock them out. Remember that the Uniden has Temporary and Permanent Lockouts, if you want to lock out the TG's for good press the LO button twice, if you want it to restore the next time you turn on the radio just press it once.
In the McHenry County area, besides the county and some of the local agencies, you should be able to hear State Police and other state agencies (DNR, SOS etc.), Boone & Winnebago (and soon DeKalb) County units, Tollway maintenance and police, and other traffic, so a good lockout regimen will help.
You could also edit the scan lists within ARC-XT and add/subtract talkgroups as you wish. The CARMA Profile and the RR Database have excellent and complete listings of talkgroup assignments. so you can cherry pick the targets you want.
Enjoy!
