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When the scanner receives a transmission on a channel
set to the PL mode, it first decodes the PL tone included
with the transmission. In the Open mode, the scanner
stops on the transmission and displays the PL tone on
the bottom line of the display (or displays None if no tone
is included). In the Closed mode, the scanner only stops
on the transmission if the PL tone matches the tone that
you specified for the channel.
PL tones range in frequency from 67 Hz to 254.1 Hz. You
select a PL tone by pressing
STEP
while programming a
channel.
DPL Mode
This sets the scanner to decode digital PL tones used
with some FM transmissions. Similar to PL, DPL is a digi-
tal “signature” encoded on a subaudible carrier. In addi-
tion to preventing interference from other nearby radio
systems, DPL can also identify a specific user or group of
users on a radio system. When you select the DPL mode
for a channel, you can also set a specific DPL code for
that channel.
When the scanner receives a transmission on a channel
set to the DPL mode, it first decodes the DPL code in-
cluded with the transmission. In the Open mode, the
scanner stops on the transmission and displays the DPL
code on the bottom line of the display (or displays None if
no code is included). In the Closed mode, the scanner
only stops on the transmission if the DPL code matches
the code that you specified for the channel.
DPL codes range from D017 to D754 (only 100 codes are
actually used within this range). You select a DPL code
by pressing
STEP
while programming a channel.
DPL is not as popular as PL, because the effective range
of DPL-encoded signals is less than PL.
20-522.fm Page 30 Friday, September 17, 1999 12:46 PM
