OK - the Pro-94 is a "trunking" scanner... so far, so good.
Here's how is works ...
A "system" (i.e. your local government) is given a
set of frequencies to use for public safety and/or
general public services.
Unlike older HF/VHF/UHF frequencies assignments which
designated a frequency to a specific use (i.e. 154.01 =
fire department dispatch), the trunking systems share
all of the frequencies across all users of the system.
In the old systems as described above, when a radio
was programmed, it was set to transmit and receive on a
specific frequency.
Today's radio systems are programmed with an ID and
a group of frequencies to communicate on.
When the user pushes the button to talk, the radio sends
it's ID to a central computer and based on a variety of
factors (user type, priority, etc.), the computer immediately
assigns that radio a frequency to talk on (could be one of
almost any in the "system" of frequencies. Each time the
user pushes the button to talk, the computer could assign it
a completely different frequency in the system.
Instead of programming the radios with specific frequencies,
the radios are programmed with "talkgroups" (16, 57360, etc.)
which are effectively the channels the users talk on.
So, you need both programmed (unless you have a radio
that can program itself once you identify the "control"
channel frequenc(ies).
Best thing to do is program your system frequencies, and
then use the "search" function on your radio to watch for
the "talkgroups". Additionally, you can look at the Radio
Reference trunk system database info for your area. It will
tell you the frequencies AND the talkgroups and who is
assigned to each of the talkgroups.
