Uniden UBC72XLT Scanner User Manual


 
11
Understanding Scanning
Understanding Scanning
This section provides you with background on how
scanning works. You don’t really need to know all of
this to use your scanner, but some background
knowledge will help you get the most from your
UBC72XLT.
What is Scanning?
Unlike standard AM or FM radio stations, most two-
way communications do not transmit continuously.
Your UBC72XLT scans programmed channels until
it finds an active frequency, then stops on that
frequency and remains on that channel as long as
the transmission continues. When the transmission
ends, the scanning cycle resumes until the scanner
receives another transmission.
What is Searching?
The UBC72XLT can search for active frequencies.
This is different from scanning because you are
searching for frequencies that have not been
programmed into the scanner. When you select
frequency bands to search, the scanner searches
for any active frequency within the lower and upper
limits you specify. When the scanner finds an active
frequency, it stops on that frequency as long as the
transmission lasts. If you think the frequency is
interesting, you can program it into one of the banks.
If not, you can continue to search.
Conventional Scanning
Conventional scanning is a relatively simple concept.
Each group of users in a conventional system is
assigned a single frequency (for simplex systems) or
two frequencies (for repeater systems). Any time one
of them transmits, their transmission always goes
out on the same frequency. Up until the late 1980’s
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