E.F. Johnson 5100 SERIES Service Manual - page 24
OPERATION
2-13
September 2001
Part No. 001-5100-001
you are out of range of the repeater, you cannot talk to
anyone else on that channel even though the mobile
you are calling may be only a short distance away. To
allow communication when this situation occurs,
repeater talk-around can be used to allow direct
communication with a mobile without going through a
repeater.
Repeater talk-around can be selected if the
Repeater Talk-Around option switch (if available).
When talk-around is enabled by this switch, “RTA
ON” is flashed in the display. Then when it is disabled
by pressing the switch again, “RTA OFF” is flashed.
Changing channels or turning power off does not
change the selected talk-around mode.
2.6.10 POWER OUTPUT SELECT
If the High/Low Power option switch is
programmed and power selection is permitted on the
current channel, either high or low transmitter power
can be selected. Generally, the high power setting
allows you to transmit longer distances but uses more
battery power, and the opposite occurs with the low
power setting.
Pressing the High/Low Power switch toggles the
power setting. The new level is flashed in the display
when this switch is pressed as “HI POWER” or “LO
POWER”. If power selection is not permitted on the
channel, the fixed power level is flashed and no power
change occurs. Turning power off or changing chan-
nels does not change the power setting selected for a
channel. Selectable power is not available with 800
MHz models.
2.6.11 EMERGENCY MODE (CONVENTIONAL)
On conventional channels, an emergency mode
may be programmed to be selectable by the Emer-
gency switch located next to the antenna (see illustra-
tion in Section 2.3.2). Scanning is automatically
disabled in the emergency mode, so transmissions
occur on the selected channel.
If an analog channel is selected and scrambling is
programmed, pressing the Emergency switch sends an
emergency signal on the selected channel 20 times or
until an acknowledgment is received. Keying the radio
also cancels the emergency condition.
If a Project 25 (digital) channel is selected,
pressing this switch selects the emergency mode and if
the PTT switch is pressed, an emergency status is sent.
Radio power must be turned off to cancel the emer-
gency mode on a Project 25 channel.
2.6.12 CONVENTIONAL MODE SCANNING
General
The following information describes scanning
features unique to conventional operation. Scan opera-
tion common to all modes is described in Section 2.5,
and scan operation unique to SMARTNET/
SmartZone operation is described in Section 2.7.12.
Selecting a Scan List
With full keypad (18-key) models, one of up to
three scan lists can be selected when scanning with a
conventional channel selected. These lists can be
system operator or user programmed as described in
the information which follows. With limited keypad
(6-key) models, only one scan list is available and it
cannot be user programmed. However, nuisance chan-
nels can still be temporarily deleted as described on
Section 2.5.8.
Proceed as follows to select a scan list with full
keypad models:
1. If required, enable scanning by pressing the Scan
option switch.
2. To select a list, press the number key corresponding
to the number of the desired list (1-3). The selected
list is then briefly displayed as “Scan x” where “x”
is the list number. The selected scan list is stored in
memory and does not change until this procedure is
repeated.
Transmitting in Scan Mode
Each conventional scan list can be programmed
for one of the following modes. These modes deter-
mine if priority sampling occurs and also the channel
on which transmissions occur while scanning. Refer to
the next section for more information.