You'll need to program the radio frequencies into your scanner before it will scan . For a list of frequencies in Anoka County CLICK HERE .
For specific programing instructions for your UNIDEN refer to your owner's manual. They will give you a step by step instruction on how to program the frequencies into your scanner memory (If you need a manual, CLICK HERE
...be sure to select the scanner option on their pull-down menu.
THEN when you have the radio frequencies stored into your scanner, you'll be able to press scan and away you go.
Be sure to adjust the squelch just high enough to eliminate the static...turn the squelch counterclockwise until you hear loud static, then turn Clockwise just enough to silence static...
Let us know if you still have trouble.