Is there any way to save UniTrunker logs? I have the option checked that says it logs to a file, but it doesn't seem to be making a file, or if it is, I have no idea where the file is located
They're saved in folders inside your Unitrunker program folder. R######## for receivers and S######## for systems (sites). Easier to browse them with the browse button on the software itself (magnifying glass, I think) since the folder names have no real bearing on the system. Example, S0000002 or S0000114 might refer to system XYZ-BEE00, but there's no way of knowing unless you peek inside the Unitrunker.xml manually.
Well, the first part is the date. (2010-12-22 at 05:00:06 Universal Coordinated Time). "Joins" means an affiliation (the radio signed on to the talkgroup). If I read the rest correctly (and remember it right), radio 4750 (I = Individual, or radio) joined group (G = Group) 543.
The guy who writes Unitrunker is active on these forums and will undoubtedly be here eventually to fill in any gaps I've skipped over. There's also probably some info on the RR Wiki about what all the info means.