i have a BCD436HP and really love it. I am new to this hobby and am still learning a considerable amount. lol The question i have is that you can set the unit with the zip code and then set the rage, which i did. 20 mile range the issue im having is that im not getting the full conversation of certain agencies. So i set up a favorites list and the set the specific channels as priority at 2 seconds. are there hidden frequencies that radio reference is unaware of? these are small communities and dont think thay are trunked or anything like that
If you know exactly what you want to scan, I would put it in the Favorites List you created. Then, I would select Menu> Set Scan Selection> Select List to Monitor. I would then make sure your Favorites List is on, and then turn the Full Database Off.
If you wish to monitor the Full Database, a 20 mile range is going to take way too long to scan, in most locations. You could bring the range to 0. And you could also select (through the menu) Select Service Types, and turn off the Service Types you are not interested in hearing.
Your issue may be simplex channels, as indicated. It can also be the scanner has so much to scan the way it is currently set, that it does not make its "rounds" back to the channel you are wishing to hear. The above should help speed the scanning up by reducing what you are listening to. If you are creating Favorites Lists (which I would, too), I would probably turn off the Full Database scan. Turn the FL on and listen to exactly what you want.
If you give us your location, we can probably give you more precise ideas. By the way, Welcome to RadioReference!