The database have ranges set to frequencies and talk groups and those have been put there by a human person. That person might not have the proper info or knowledge when setting the range value. You probably have to be almost a radio expert to actually be able to determine a sites actual coverage. The database depend of what people report in to it, but if no radio knowledge person are in that area then the range values might be way off.
Some frequencies have been set to 5 miles when they can be heard at least 20 miles by scanner listeners. Sometimes sites do not have the correct GPS positions and can be miles from where they are actually placed.
When you set the scanners range to zero you are using the exact range values from the database. If you set the scanner to a 10 mile range you'll add that to the database values. The need to set larger values in the scanner are crucial and are made available by Uniden due to errors in the database and different antennas used and how well the listening location works to receive different sites. Also time of season and wheather will influence a sites coverage range. The database values are likely set to work when you drive and use GPS control and with a limited antenna and only loads the extreme local systems as they are probably your first priority to monitor. But it is probably far from what the scanner can actually hear and monitor, especially if you are at home and using external antennas.
What you could do when starting fresh and monitoring from home are to set the range to the highest value and input your loacations coordinates. Then when you hear a site or a frequency, write that down and avoid the site or frequency and later move that to a favorite list in Sentinel. Do not avoid talkgroups, they do not slow down scanning, only frequencies and sites do. After a while you have a favorite list containing only the things you can hear and will be scanning from home. You can do different favorite lists for the stuff that are out of state and/or noninteresting but could be useful to have prepared for use at another time. You usually don't need to use location controlled scanning in favorite lists so turn that off in Sentinel or in the scanners menu for the favorite lists.
/Ubbe
