No Scanner Traffic From LAPD Frequencies

Hi:



I recently bought a Uniden BC345CRS. I have programmed a number frequencies associated with the Los Angeles County Sheriff's Department (LASD), which can be found here:



http://ift.tt/1GSwLqQ



I get a lot of scanner traffic. However, when trying the same for the Los Angeles Police Department (LAPD), the first 40-50 frequencies found below, all I get is static, white noise, or no noise at all.



Los Angeles Police Department (LAPD) | SCMA



Can anyone suggest what the trouble might be or any change I can make? Thanks.

No Scanner Traffic From LAPD Frequencies