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Busy Indicator - With scanning disabled, note if the multi-function indicator on the 
front panel is steady green. If it is not, the channel is not being used and a call can be 
transmitted. If it is green, a carrier is being detected, so the channel may be busy.

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 5.4.1).

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:

• Call Guard (CTCSS/DCS) squelch is disabled on analog channels and NAC and group 

ID detect are disabled on P25 (conventional) channels.

• Busy Channel Lockout is overridden (see next section).

• 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) and the 
receiver unsquelches.

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.

3 To disable the monitor mode and return to normal operation, press the MON option 

switch again.

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 4.8). Pressing the SEL SQ option switch disables Call Guard squelch/P25 
group ID detect but not scanning and P25 NAC detect (see Section 5.4).