[Scanner] Scanning a digital system?

[John Burch]

Newbie question - how can one determine what the digital 
format or type of system is before plunking down $600 for 
a "digital ready" scanner?  (As far as I can determine, Motorola
built the system a year ago, and when listening to the assigned 
frequencies, all I hear is buzz saw or machine gun-sounding 
racket.  No analog voice is ever heard anywhere.)

How does one determine the data speed on the control
channel?  I assume that the two popular choices are
3200(?) or 9600 bps?

Thanks very much for any assistance or hints.

John
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