Uniden UBCT8 - Manual (Page 8)

Terminology
What is Scanning?
What is Searching?
What is Trunk Tracking?
Unlike standard AM or FM radio stations, most two-way communications do not transmit
continuously. The UBCT8 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.
The UBCT8 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 band
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.
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 MHz, the fire department on 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.
467.850 161.250
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.