Uniden UBCT9 - Manual (Page 8)

4
Terminology
What is Scanning?
Unlike standard AM or FM radio stations, most two-way communications do not
transmit continuously. The UBCT9 scans the Frequencies you have programmed
into the Scanner’s channels until it finds an active frequency.
Scanning stops on an active frequency and remains on that channel as long as
the transmission continues. When the transmission ends, the scanning cycle
resumes until another transmission is received.
What is Searching?
The UBCT9 can search each of its 12 bands to find active frequencies. This is
different from scanning because you are searching for frequencies that have
not been programmed into your Scanner’s channels. The scanner automatically
chooses between two speeds while searching. During search mode the scanner
will search 100 frequencies per second for bands with 12.5 kHz steps and during
Turbo SEARCH mode the scanner can achieve up to 300 frequencies per second
for bands with 5 kHz steps.
What is Trunk Tracking?
Conventional scanning is a simple concept. You enter a radio frequency in your
scanner’s memory which is used by someone you want to monitor. For example,
the police in your area may broadcast on 467.850 MHz, the fire department on
161.250 MHz, etc.
So when your scanner stops on a frequency, you usually know who it is, and more
importantly, you can stop on a channel and listen to an entire conversation.
As the demand for public communications has increased, many public radio
users don’t have enough frequencies to meet their needs, and this has created
a serious problem. Trunking radio systems have been implemented to solve this
problem.
In a trunked radio system the frequencies are shared among the police and fire
departments and a computer systematically assigns available frequencies when
they are needed for communications.
UBCT9 OM 4 12/11/07 3:52:26 PM