Draft 02 - Sep 1 2015
4-8
Viking Mobile Radio Operating Manual
Radio Wide Features
4.9
Microphone Off-Hook Detect
The microphone hanger can be connected to chassis ground and the radio programmed to
detect an off-hook condition (Hangup Box Monitor selected). The following operation
then occurs when the microphone is taken off-hook:
Conventional Channel Selected
- Scanning temporarily halts (if applicable) and the
Monitor Mode described in Section 5.2 is enabled. However, the receiver unsquelches
only if a carrier is detected.
SMARTNET/SmartZone/P25 Trunking Channel Selected
- Scanning temporarily
halts if applicable.
If the off-hook condition is not detected (Hangup Box Monitor not selected), the
microphone hook state has no affect on radio operation.
4.10
Surveillance Mode
If the Surveillance mode is programmed, the backlight, all alert tones, and front panel
LED indicator can be disabled individually or totally, based on programming.
The transmit/receive LED indicator, display and keypad backlight, and all alert tones can
be disabled. When setting is enabled, the radio will power up in Surveillance mode with
the selected options active. A function button can also be assigned which will activate and
deactivate surveillance mode at the user’s discretion. It overrides any other programming
of these functions such as a Tone or Backlight option switch.
This feature can be turned ON and OFF by the user via menu selection or by the
Surveillance Mode option button (if programmed). The user selected mode permanently
overrides the programmed mode if applicable.
4.11
Public Address
This feature allows a single microphone to be used for either radio or public address. An
external public address system can be connected to the radio accessory pigtail cable.
External PA function without a siren controller is provided for cases when the siren
function is not required. This is a low level output, so some type of PA amplifier is
required. The Mic To PA option button (or menu selection) controls this feature.
