Specifications
8
• Aircraft
• Amateur radio
• PMR users
• Broadcast AM/FM/TV stations
• Many other business radio users
When you want to store a conventional system, all you need to
know is the frequencies they operate on. When you are
scanning a conventional system, the scanner stops very briefly
on each channel to see if there is activity. If there isn’t, 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.