Icom IC-F610 Instruction Manual page 27

Either Trunking or Conventional mode;
[Mode]
Push this key to toggle between Trunking mode and
Conventional mode.
[Null]
No function is assigned.
[High/Low]
Pushing this key will toggle in the order of Low1 power,
Low2 power, High power and Auto power.
[Public Address]
Use the transceiver as an amplifier.
[RX Speaker]
Output the receive audio to an out of vehicle speaker.
CONVENTIONAL MODE
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