First, go back and read the article I linked.
The range settings in the database reflect how far a site can be received, or the service area of an agency, and shouldn't be changed by novices. If you mess with those settings, you're going to screw things up.
If using a handheld or indoor antenna, the scanner Range setting (in the location menu) should be set to 0, or no more than 5. In a mobile, the max scanner Range setting should be 10-15. If you have a base station outdoor antenna on a high tower with good coax, you can set the scanner Range setting up to 30. But the higher you set the scanner Range, the more stuff the scanner will try to monitor, and you are more likely to miss traffic. Unless you live in an extremely rural area and have a huge antenna tower, you should never use a range setting of 50.