It's nearly impossible to receive PG from outside PG County -- there are many, many posts concerning this you will probably want to read.
The issues are very similar to the newly upgraded systems in Baltimore City and County County.... again, many posts for those as well here in the Forum. In my testing, it's amazing (and irritating) how the reception seems to "refuse" to come across the County lines.
If you drive down into PG County it's pretty good but you will still find some spots that appear "dead" to any scanner.
I have found that if you drive to the parking lot of the Target store on Rt 198 near Russet Green, the reception there is really good (for being in AA County). You can get it to work in other spots too but it takes alot of effort and trying different antennas.
And before you start thinking it's a PSR-800 or GRE only problem -- it's not.
Uniden and GRE are both well aware of these issues -- and hopefully will come up with a solution in the near future --- I have to believe this is true.
I still recall when I bought my first 800Mhz scanner that didn't know how to follow trunking systems - and was I thrilled when the Uniden BC-235 came out -- and then unhappy again with Uniden when systems started going digital - but then thrilled again when I tried the Radio Shack PRO-96 (a GRE product) for the first time!
It may take time, but I'm sure they'll work it out.....
