By high UHF, are you referring to the UHF T-Band (470 to 512 MHz)? I'm in the North Shore area, and I never had a problem receiving anything in that band while using my SDS100. I agree with the above post that there's many factors that may contribute to your issue. Also, agencies in many cities, including Chicago, have reported issues with the UHF T-Band ever since DTV channels started changing frequencies. That's why the Chicago Fire Department is currently using the city's 800MHz P25 system, and eventually will switch over to 460MHz due to issues with their T-Band freqs.