Are you trying to listen to agencies that are on a trunked radio system, like the S&P NXDN system or the AIRS P25 system? If so, you may not be able to hear traffic outside your region unless you get a better antenna that can pick up the control channels being broadcast from closer to your target zones. At least, that's assuming that you've properly programmed in those other counties' info into your scanner.
As an example, if you're in Houston County and trying to monitor agencies on AIRS in Dale County, they may not be on the Houston County AIRS sites because it's outside their target coverage zone. Unless a Dale County radio travels to your area, you won't ever hear anything off the Houston County AIRS sites. But if you can get a good antenna up higher and pick up a control channel for an AIRS site in Dale County, you would probably hear everything then. AIRS is 700/800 MHz and it's a lot like cellular, the signals don't travel all that far compared to conventional UHF and VHF.
It's not a 100% certainty, but that's been my experience with trunked radio stuff over here in Baldwin County. Sometimes I can't hear a fire department less than 15 miles from me because they're not being relayed on my local towers… but then again I often hear EMS calls from Atmore which is over 40 miles away, all because they're being carried on a tower between me and them so I get them that way. It's kind of weird to grasp at first but eventually it makes sense.
The S&P NXDN system that's popular up there is on VHF and has great range, so if it's already programmed in, an antenna in a higher location should help.
I'm using an SDR on a PC, not a dedicated scanner, so my radio reception is not nearly as good, but my limit for reception on 700/800 MHz is like 15 miles tops, and that's with a simple outdoor antenna 30 feet up. But on VHF I often hear that S&P system out of Geneva County when band conditions are good even though it's probably 80 miles away.
