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the scanner quickly moves to the next channel. If there is,
then the scanner pauses on the transmission until it is over.
Simplex Operation
Simplex systems use a single frequency for both transmit
and receive. Most radios using this type of operation are
limited to line-of-sight operation. This type of radio is
frequently used at construction job sites, and with
inexpensive consumer radios such as PMR radios. The
range is typically 1.5-12 km, depending upon the terrain and
many other factors.
Repeater Operation
Repeater systems use two frequencies: one transmits from
the radio to a central repeater; the other transmits from the
repeater to other radios in the system. With a
repeater-based system, the repeater is located on top of a
tall building or on a radio tower that provides great visibility
to the area of operation.
When a user transmits (on an input frequency), the signal is
picked up by the repeater and retransmitted (on an output
frequency). The user’s radios always listen for activity on the
output frequency and transmit on the input frequency. Since
the repeater is located very high, there is a very large line of
sight. Typical repeater systems provide coverage out to
about a 40 km radius from the repeater location.
Where To Obtain More Information
By itself, this manual really only provides part of what you
need to know to have fun scanning – how to program and
use the scanner.
Information On The Internet
The Internet is a great source for current frequencies and
information about scanning.
Many web sites have lists of frequencies for your area. You
can use a search engine to find and use them.
Make a list of the agencies you want to listen to, then look
up the frequencies and systems used by those agencies.
