Gideon Wrote:
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> Well, getting a scanner would be a good idea in
> BFE, but Fairfax County converted an 800Mhz
> trunked dispatch and communications system about
> five years ago and scanners are pretty much
> useless unless you are willing to drop serious
> $$$. I am far from a technical wizard, but my
> understanding is that there are hundreds
> (thousands?) of 'frequencies' and a computer
> controls how they are managed. Even when an
> incident moves to Channel 'x', you still cannot
> eavesdrop unless you have a compatible radio.
Fairfax County currently has an 800MHz Digital (APCO25) Trunked Radio System that they use for Fairfax County Police, Fire, Rescue, Sheriff, School Security, Fairfax City Police, Herndon Police, and Vienna Police.
What this means, is that they have about 20 actual frequencies, but they have about 180 channels. Whenever a cop, firefighter, EMT, or anyone with a radio transmits, the signal goes to a central computer, which tells the radio that is transmitting to go to a specific frequency, and tells everyone else listening to that channel to go to that frequency. Fairfax County also has a digital system, which means that everyone voice is converted to data before it is sent over the air.
Basically, what this means is you need a special Digital Trunking scanner to monitor them. Any scanner that can do "Digital" or "P25" will probably be good, I have a Uniden BCD396T (List $529.95), and I am able to listen to pretty much anything. If there's a fire, I hear it. If police are going somewhere, I hear about it.
One other thing to note is that almost every police car has a computer in it, so with many calls, all you'll hear is the initial dispatch (units assigned, address of incident, details of incident). Officers generally will run tags, run people, give dispositions of calls, etc, on their computer.
If you want some more info about scanning, check out
http://www.radioreference.com/modules.php?name=TRSDB&sid=182