E F Johnson Company 2425M70 Benutzerhandbuch
6-2
Conventional Features
Busy Indicator - With scanning disabled, note if the multi-function indicator on the
front panel is steady green. If it is green, a carrier is being detected, so the channel may
be busy. If it is not, the channel is not being used and a call can be transmitted.
front panel is steady green. If it is green, a carrier is being detected, so the channel may
be busy. If it is not, the channel is not being used and a call can be transmitted.
Monitor Mode - There may be times when the busy indication is displayed even
though no one is using the channel. Monitoring should then be performed by disabling
Call Guard squelch (or group ID detect on P25 channels). This is usually done by
selecting the Monitor Mode (see following) or by the Normal/Selective option switch
(see Section 6.4.1).
though no one is using the channel. Monitoring should then be performed by disabling
Call Guard squelch (or group ID detect on P25 channels). This is usually done by
selecting the Monitor Mode (see following) or by the Normal/Selective option switch
(see Section 6.4.1).
6.2
Monitor Mode
The monitor mode unsquelches the receiver and monitors the channel even if a carrier is
not detected. Other features of this mode are as follows:
not detected. Other features of this mode are as follows:
• Call Guard (CTCSS/DCS) squelch is disabled on analog channels and NAC and group
ID detect are disabled on P25 (conventional) channels.
• Signalling-dependent Busy Channel Lockout options for Tone/NAC and P25 status are
ovrerridden (see next section). (Noise option is not overridden: Monitor mode disables
the protocol-signalling events that the Busy Channel Lockout option Tone/NAC/Status
depend on, but not carrier events.)
the protocol-signalling events that the Busy Channel Lockout option Tone/NAC/Status
depend on, but not carrier events.)
• Scanning temporarily halts.
The Monitor Mode operates as follows:
1 To monitor the transmit frequency for activity before transmitting, briefly press the
MON option switch. The display then indicates “MON” (see Figure 2.3). The receiver
unsquelches and noise is heard even if carrier not present. The transmit frequency can
also be monitored by selecting TX Channel from the menu.
unsquelches and noise is heard even if carrier not present. The transmit frequency can
also be monitored by selecting TX Channel from the menu.
2 To monitor the receive frequency instead, press and hold the MON option switch until a
tone sounds (approximately two seconds). This can be used, for example, to improve
reception if intermittent squelching is making a weak message difficult to understand.
The receive frequency can also be monitored via the Squelch Override option of the
menu.
reception if intermittent squelching is making a weak message difficult to understand.
The receive frequency can also be monitored via the Squelch Override option of the
menu.
3 To disable the monitor mode and return to normal operation, press the MON option
switch again (or select Off from the menu).
If off-hook detection is enabled, taking the microphone off-hook monitors the receive
frequency similar to Step 2. However, the receiver unsquelches only if a carrier is detected
(see Section 5.9). Pressing the SEL SQ option switch disables Call Guard squelch/P25
group ID detect but not scanning and P25 NAC detect (see Section 6.4).
frequency similar to Step 2. However, the receiver unsquelches only if a carrier is detected
(see Section 5.9). Pressing the SEL SQ option switch disables Call Guard squelch/P25
group ID detect but not scanning and P25 NAC detect (see Section 6.4).
Draft 4/29/2014