E F Johnson Company 2425795 사용자 설명서

Viking™ VP600 Portable Radio Operating Manual

5-3

The Normal/Selective function disables Call Guard squelch and P25 group ID detect but 
not scanning and P25 NAC detect (see Section 5.4.6, "Selective Squelch Code Select 
(CTCSS / DCS / NAC)").

The Busy Channel Lockout feature (also called Transmit Disable on Busy) automatically 
disables the transmitter if the channel is busy when the PTT switch is pressed. When the 
transmitter is disabled by this feature, “Busy” is displayed, a busy tone sounds, and the 
transmitter is disabled.

If Busy Channel Override is permitted by programming, it is possible to transmit even 
when the transmitter is disabled by this feature. Release the PTT switch and then quickly 
press it again (within one second).

Tone or digital Call Guard squelch (also called CTCSS/DCS signaling) can be 
programmed on each conventional analog transmit and receive channel in any order 
desired. The reverse burst and turn-off code are always transmitted and also detected on 
channels programmed with Call Guard squelch.

The Call Guard squelch feature eliminates distracting messages intended for others using 
the channel. This is done by using a subaudible tone or digital code to control the squelch. 
This tone or code is unique to a user or a group on that channel. This tone or code is 
transmitted with the voice signal but is not heard because it is in the subaudible range and 
is attenuated by a filter. Call Guard squelch must be used in both the transmitting and 
receiving radio to be functional.

The Normal/Selective option button (if programmed) or menu parameter can be used to 
disable receive Call Guard squelch on analog channels or talkgroup ID code detection on 
P25 channels. When selective squelch is disabled, “Squ Normal” is flashed in the display, 
and when it is enabled, “Squ Selectiv” is flashed.