E F Johnson Company 2425770 User Manual

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3-14 
Viking Portable 600 Radio Operating Manual
General Operation
3.10 Operation At Extended Range 
When approaching the limits of radio range, the other party may not be able to hear your 
transmissions and there may be an increase in background noise when messages are 
received. You may still be out of range even though you can hear a message. The reason 
for this is that the signal you are receiving is usually transmitted at a higher power level 
than the one transmitted by your radio. Communication may be improved by moving to 
higher ground or away from shielding objects such as tall buildings or hills.
3.11 Radio Operating Modes
Each selectable channel can be programmed for the conventional (analog or Project 25 
digital), SmartNet/SmartZone, or Project 25 digital trunking operating mode. For example, 
Zone 1/Channel 1 could be a conventional channel, Zone 1/Channel 2 a P25 Trunking 
channel, and so on. More information on these modes follows.
Note
All operating modes utilize certain functions that are activated/deactivated by pressing 
and holding a particular key/button or switch. The “hold” interval is preset. When 
instructed to “press and hold”, do so until the desired action occurs. For other operations 
(not specified “press and hold”) only momentary pressing is required.
 
 
The user has the ability to use two different timers for Emergency mode (Conventional 
system) - one to enable and one to disable emergency mode, preventing accidental 
enabling and disabling of emergency mode. With Emergency Press and Hold enabled, 
emergency mode is enabled when the Button Press/Hold Duration Timer expires. In both 
cases, emergency mode is cancelled when the Button Press/Hold Emergency Cancel Timer 
expires. 
3.11.1 Conventional Mode
This is a non-trunked operating mode which accesses independent radio channels. There is 
no automatic access to several channels. Selecting a conventional channel selects a 
transmit and receive frequency and other channel parameters such as squelch control 
coding.
Conventional channels can be either standard (analog), Project 25 (digital) or mix mode. 
With digital operation, the Digital Signal Processor (DSP) converts the audio signal to 
digital data packets. Another difference is that analog channels use Call Guard (CTCSS/
DCS) squelch control and Project 25 channels use a Network Access Code (NAC) and 
talkgroup ID codes.
Preliminary Draft 3/9/12