To Enable Or Disable Ptt Id Transmission; To Change The Default Squelch Modes; To Select The Frequency Step Size - Motorola GP68 Service Manual

GP68 Portable Radios Service Manual
A valid keypress tone sounds when the memory
channel data has been successfully copied over
to the MHz mode.

To Enable or Disable PTT ID Transmission

The radio transmits a programmable DTMF identification
code (unit ID), indicating which portable is in operation. The
PTT ID can be edited using the S pecial Programming
Mode (see page 4-10).
During a conversation, the code is normally sent only on the
initial PTT press (unless PTT ID has been disabled). The
' TX ' indicator lights for the duration of the PTT ID. If there
is no PTT or receive activity for 7 seconds, or if you change
the frequency or channel (or scan resumes), the PTT ID is
once again transmitted on the next PTT press.
NOTE
PTT ID can be enabled/disabled by pressing
and holding . Upon pressing the button
you will hear a beep; hold the button down
until you hear a second beep, indicating that
the PTT ID status has been changed, then
release the button. When PTT ID is disabled ,
the "dot" indicator flashes on the display.

To Change the Default Squelch Modes

Carrier squelch (CSQ), Tone Private-Line (PL) and Digital
Private-Line (DPL) operations are configurable on a per
channel basis. If an option board is installed, Signalling
squelch (SelCall) operation will also be configurable on a per
channel basis. If the Squelch Mode is set in Megahertz mode,
then it will become the channel's default squelch mode when
the information is programmed into a channel.
SIG SQL
B
A
Figure 4-8 Changing the Default Squelch Modes.
To change squelch modes temporarily for a channel:
SIG
Momentarily press
1
Coded (PL/DPL) and Signalling squelch modes.
IMPORTANT
Squelch modes reset to the previous pro-
grammed values when the channel is
changed. Squelch mode changes in MHz
mode are permanent.
When ' CTCSS ' is off, the radio operates in CSQ mode. In
this mode, you will hear all conversations on the selected
receive channel.
When ' CTCSS ' is on continuously, the radio operates in
Coded (PL/DPL) squelch mode. In this mode, you will hear
March, 1997
LOW SCAN
D
C
N-DEL
to change between CSQ,
A
Figure 4-9 LCD Display for Changing Default Squelch
only those conversations on the selected receive channel
which have the same PL/DPL code as your radio.
When ' CTCSS ' is flashing (which requires that an option
board is selected first via the Option Board Setup Mode), the
radio operates in Signalling squelch mode, and unmutes only
after a valid Voice Selective Call (SelCall) has been decoded.
The radio automatically enters CSQ mode for a period of
time. If there is no receive activity, the radio resumes Signal-
ling squelch mode and the LCD reverts to the appropriate
receive mode display.
When transmitting in Signalling squelch mode, PL/DPL is
transmitted if the Transmit PL/DPL code is non-zero (unless
the Transmit PL/DPL is programmed for ' 000 '). After PTT
is released, the radio automatically enters CSQ mode for a
period of time. If there is no receive activity, the radio
resumes Signalling Squelch mode. No visual indication is
given.
Refer to Receiving a Voice Selective Call in the User's
Manual for more information on this squelch mode.
A radio equipped with a Voice SelCall option
operating in the PL/DPL mode unmutes for
the correct PL/DPL code, or if a SelCall is
decoded.

To Select the Frequency Step Size

The frequency step size determines the incremental steps
that the receiver will take when you rotate the Channel
Selector Knob , or when the radio is scanning the frequency
band.
The available frequency step sizes are 5, 10, 12.5, 15, 20, and
25 KHz.
Press and hold
1
rent frequency step size (takes about 3 seconds). For
example, the following display (Figure 4-10) represents
a frequency step size of 12.5 KHz.
2 Rotate the Channel Selector Knob to scroll through the
available frequency steps until the desired frequency
step size is displayed.
6881086C09-O
Radio Programming Information
Programming the GP68 Radio
CTCSS
Modes.
NOTE
LOW
until the display indicates the cur-
C
Figure 4-10 .
4-5