I monitor about a dozen sites in Maryland with Unitrunker, but only one dongle, not the voice following two dongle setup.
The key is to get the offset on the dongle determined so you can properly tune the control channels. I use the Sharp application for this, tune in a known control channel, and then play with the offset until it is the clearest. Then I set Unitrunker's receiver for that offset. This results in Unitrunker being properly tuned. You can uncheck the mute selection on the receiver when you set the offset to verify the improvement in tuning. Each dongle is a little different. I have 3 and none are the same.
So, once you fire up Unitrunker, go to the receiver, and set up a receiver for the dongle. Enter the setup, and start the receiver. Once it is running, it should open up a monitor window for that system, populating all the frequencies and starting to show active talkgroups and radio ID's
You can click on either and using the label field, name them wit text descriptions.
Mark
536/436/WS1095/HP1/HP2/996T/996XT/996P2/396XT/325P2/PSR800/15X/others