Understanding Your Pro-92'S Modes - Radio Shack PRO-92 Owner's Manual

20-522.fm Page 28 Friday, September 17, 1999 12:46 PM
Low Freq. Hi Freq.
(MHz) (MHz)
452.1875 452.9625
470.0000 512.0000
150.7750 150.9650
Note: The steps shown above are default values. You
can select any desired step setting.
UNDERSTANDING YOUR
PRO-92'S MODES
You can program each channel with any of seven receive
modes. Each mode affects how your scanner operates
when scanning and receiving transmissions, and also af-
fects what transmissions you receive when you set the
scanner to the Closed mode (see "Open and Closed
Modes" on Page 63). The following sections describe
each mode and how they affect your scanners operation.
See "Changing the Receive Mode" on Page 53.
PL, DPL and trunking systems all use some form of cod-
ed squelch . Coded squelch techniques involve the trans-
mission of a special "code" signal along with the audio of
a radio transmission. A receiver with coded squelch only
activates when the received signal has the correct "code."
This lets many users share a single frequency, and de-
creases interference caused by distant transmitters on
the same channel.
In all major metropolitan areas of the United States, every
available radio channel is assigned to more than one us-
er. Public safety radio systems on the same frequency
are usually set up at a distance of forty miles apart, or
more. This means that you may hear transmissions from
a distant system when your local system is not transmit-
ting. By entering the PL for a local system, and operating
the bank in closed mode, the scanner will not stop on
transmissions from the distant system.
28
Step
Description
(kHz)
25 Taxi/Busses
12.5 T-Band
5 Tow Trucks