I have downloaded a trunked system but in my area it contains so many other (non Law Enforcement) frequencies on the trunked system that it is not user friendly. Is there any way to only get the LE channels and not Fire/Public works, etc?
When you select the trunked system to download you should see the system below listed with plus signs (+) next to each click on the plus sign to drop it down and select the things you want to down load.
You can always just delete the talkgroups that you're not interested in. Or, if you are only interested in a few, you can just cut and paste those into a new group that you create and delete all the other groups.
In a trunked system you only need the control channel programmed and maybe the alternates if they rotate control channels. The main system I monitor uses about 20 different frequencies but I only program in the main control channel.
Marc if you still need more help tell us what state and system you're scanning and what scanner you're using and someone can probably even tell you what keys to punch.
On Radio Reference you rarely see someone giving too much information when seeking help.