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33

Changing the Priority Channel

If a fixed priority channel is associated with the 

current scan list, it can be changed if the Priority 
option switch or menu parameter is programmed. With 
dual priority, this function changes only the first 
priority channel. To change both priority channels, use 
the Scan List Edit function described in Section 4.9.1. 

Proceed as follows to change the priority channel 

using the Priority option switch/menu parameter:

1. Make sure scanning is disabled (

 icon not 

displayed) and the desired scan list is selected (see 
Section 4.9). 

2. Select the channel you want to be the priority 

channel and then press the Priority option switch or 
select that menu parameter. “Priority” is then 
flashed to indicate that the current channel is now 
the priority channel when scanning that list. Other 
indications that may occur are as follows:

•

If “No Priority” is displayed, priority sampling 
may not be enabled on the scan list.

•

If “Sel Chan” is displayed, the priority channel is 
always the selected channel and cannot be 
changed.

•

If no indication displayed, the scan list may not be 
user editable or the channel may not be in the scan 
list. 

Standard conventional calls are placed to other 

radio units monitoring the selected channel. The 
proper coded Call Guard squelch tone or code or P25 
NAC may need to be transmitted by your radio for 
them to receive a call (see Sections 5.5 and 5.17.3).

Placing a Standard Conventional Call

1. Turn power on and set the volume as described in 

Section 3.1. Select the channel programmed for the 
radio you want to call as described in Section 3.3.

2. Monitor the channel automatically or manually as 

described in Section 5.2.

3. Press the PTT switch and if the Busy Channel 

Lockout feature is programmed on the channel (see 
Section 5.4), the transmitter is automatically 
disabled if the channel is busy. Otherwise, busy and 
out-of-range conditions are not indicated. 

4. Press (and hold) the PTT switch to talk and release 

it to listen. 

Receiving a Standard Conventional Call

1. Select or scan the channel programmed for the call 

you want to receive (refer to Sections 4.8 and 4.9 for 
more scanning information).

2. When the call is received, press the PTT switch to 

talk and release it to listen. If scanning, responses 
may occur on the priority, selected, or receive 
channel as described in Section 5.11.2. 

DTMF (Dual Tone Multi-Frequency) tones can 

be generated for ANI (Automatic Number Identifica-
tion) and other purposes on conventional analog 
channels. One of the following options may be 
enabled on each channel:

Pre-Tx ANI - A preprogrammed ANI sequence is 
automatically sent each time the PTT switch is 
pressed.

Post-Tx ANI - A preprogrammed ANI sequence is 
automatically sent each time the PTT switch is 
released. 

When an emergency alarm or call is placed, this 

ANI signaling is replaced by the Emergency DTMF 
ID (see Section 5.10). Refer to Section 5.15 for 
information on MDC1200 ANI.

This feature allows the user to transmit a single 

tone by pressing the Single Tone Encoder option 
switch or selecting that menu parameter. Each conven-
tional system can be programmed for a tone of 500-
2500 Hz in 1 Hz steps with a duration of 0.5-2.5 
seconds in 0.1 second steps.