I own a Uniden Bearcat BCD396XT MOBILE scanner and only listen to Fire/EMS and police frequencies, which are from 151-155 MHz VHF, and occasionally a 453 MHz channel. I am curious what antenna to get for my portable scanner to pick up one of the dispatch centers around 20 mi away. Also, what gain to get and good antenna brands and type of antenna, as I am relatively new to the scanning world. Thanks!