User's Manual

GENERAL OPERATION
16
The following additional low battery indications
and conditions may be enabled by programming:
• A chirp sounds once a minute in the receive standby
and transmit modes.
• A chirp sounds each time the PTT switch is pressed.
• The top panel LED indicator flashes red every 30
seconds in the receive mode.
• Low power is selected when transmitting.
As indicated in the preceding note, the radio may
need to be connected to a constant power source to
preserve the encryption keys in memory. This is
required if “infinite key retention” is not
programmed.
To allow the battery to be changed without losing the
keys with this feature disabled, storage capacitors
maintain the supply voltage to memory for approxi-
mately 30 seconds without a battery attached. There-
fore, be sure to reattach a battery within that time. Refer
to Section 10.2 for more information on encryption
keys.
There is a battery saver feature that can be
enabled by programming. This feature functions on
trunked channels only, and it automatically selects low
transmit power when the receive signal strength
(RSSI) indicates that the site is nearby.
3.4.2 BATTERY CHARGING
NOTE: When a battery is charged while attached to
the radio, make sure radio power is off (see following).
The battery can be charged separately or while
attached to the radio. When it is charged while
attached to the radio, radio power should be turned off.
If it is not, the battery begins slowly discharging when
the charger enters the trickle charge mode. This mode
is indicated by a green Ready indication, and it is
entered automatically when the battery is nearly fully
charged. Gradual discharging occurs in the trickle
mode because the charge current of approximately 50
mA is less than the radio standby current of approxi-
mately 200 mA.
CAUTION: Do not transmit in close proximity to the
charger base (see following).
Do not expose the charger base to high level RF
signals while a battery is being charged because this
may cause a charger fuse to blow (especially in the
UHF range). Radios programmed for SMARTNET/
SmartZone operation, for example, may affiliate while
in the charger which causes them to automatically key.
Therefore, do not leave radio power on while charging
as described above.
3.5 BACKLIGHT
The backlight for the display and option keys can
be programmed to automatically turn on when any key
is pressed. It then automatically turns off after a
programmed delay of 0-7.5 seconds so that battery
drain is minimized. If the Backlight option switch or
menu parameter is programmed, the user can manually
turn the backlight on and off (it then stays on). If the
Surveillance mode is programmed, the backlight is
disabled (see Section 4.7). The radio can be
programmed so that the backlight turns on in the
keypad lock mode when a key is pressed (see next
section).
3.6 KEYPAD LOCK
The Keypad Lock feature temporarily disables
the front panel keys to prevent keys from being acci-
dentally pressed. This feature is available if the
Keypad Lock option switch is programmed. To lock
the keypad, simply press the Keypad Lock option
switch. Then to unlock the keypad again, press and
hold this switch until a tone sounds (approximately 1
second).
Permanent Keypad Lockout can also be
programmed. The keypad is then permanently disabled
and cannot be enabled by the user. Additional informa-
tion on this feature is as follows:
• A global “Front Keypad Lockout Only” function
can be selected by programming. The front panel
keys but not the side panel option keys
are then
disabled by the preceding Keypad Lock and Perma-
nent Lock functions. If this function is not selected,
both the front and side panel keys are disabled. The
PTT switch is never disabled.
• The Channel Selector and Volume controls can be
programmed so that they are locked by the Keypad
Lock function.
• The “Channel Selector Enabled” function can be
programmed globally. If this is not selected, the