E F Johnson Company 2425372 用户手册
Draft
December 2006
5300 ES Series Mobile Radio Operating Manual -3
5.3
Busy Channel Lockout
The Busy Channel Lockout (also called Transmit Disable on Busy) feature 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.
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.
The Busy Channel Lockout feature can be programmed to operate as follows. Each
conventional channel can be programmed differently.
conventional channel can be programmed differently.
“Off” - Busy channel lockout is disabled and the transmitter keys even if the channel is
busy.
busy.
“Noise” - If a carrier is detected on the channel, the transmitter is disabled when the
PTT switch is pressed.
PTT switch is pressed.
“Tone (NAC)” - If an incorrect Call Guard (CTCSS/DCS) or P25 NAC code (see
Section 5.15.3) is detected, the transmitter is disabled when the PTT switch is pressed.
An incorrect code is any code other than the one programmed for the current channel.
Section 5.15.3) is detected, the transmitter is disabled when the PTT switch is pressed.
An incorrect code is any code other than the one programmed for the current channel.
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.
when the transmitter is disabled by this feature. Release the PTT switch and then quickly
press it again.
5.4
Call Guard Squelch
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.
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 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.
5.4.1 Call Guard Squelch Enable/Disable
The SEL SQ option switch (if programmed) can be used to disable receive Call Guard
squelch on analog channels or group ID code detection on P25 channels. When selective
squelch is disabled, “SQ Normal” is flashed in the display, and when it is enabled, “SQ
Select” is flashed.
squelch on analog channels or group ID code detection on P25 channels. When selective
squelch is disabled, “SQ Normal” is flashed in the display, and when it is enabled, “SQ
Select” is flashed.