Antenna Boost for Scanners
I have a different model digital scanner from Uniden, and I really like this antenna:
Diamond D220 Mobile Scanner Antenna (it's a mobile mini discone antenna 100 to 1600MHz for receiving). I have mine mounted on a metal stand with a magnetic mount (Diamond SPM-35) with a coax cord plugging into my scanner using a BNC plug To 'N' Type Socket adaptor. For extra boost (not needed but nice to have), consider a GRE Super Amplifier for scanner which mounts on the top between your BNC and scanner unit. Note that you can also mount the Diamond D220 on a rooftop and bring into your room, but then you'd want some kind of grounding to avoid any issues.
For something more portable, you also can't go wrong with the Diamond and RH77ca with a BNC connection.
Good luck!