/diy/ - Do It Yourself

I have a Uniden 436HP scanner That I built an off center dipole antenna from 3/4" copper tubing. I'm on a hill / very large farm in the sticks and the antenna is roughly 30' off the ground. I receive some police departments / fire etc... as far away as 260 miles. Short of a signal amp is there a better option? I realize that you need to tune the antenna to a specific wavelength to get more range or maybe a yagi. I'm trying to cover the entire spectrum. I realize it's a give and take. Should I be more appreciative of my results?