Maycom AR-108 User's Operation Manual page 12

2) DW (Dual Watch) Button
To operate Dual Watch :
(1) Not in the Scan Mode, select the channel in which you want to monitor
which we will refer to as your "A" channel.
(2) Press the "FUNC + SC/DW" button, then "DW" will appear on the
LCD.
(3) Use Up/ Down key to select the "B" channel which you want to
monitor. Once "B" channel has been selected, the radio will begin
its dual watch monitoring.
▶ Display of Dual Watch Feature.
To turn off the "Dual Watch" channel, simply press the "FUNC +
SC/DW " button. Note that the radio will return to the "A" channel for
normal operation. If you press the "FUNC + SC/DW" button when a
signal is receiving on the channel "A" or "B", the "Dual Watch" feature
will be turned off, on the "A" or "B". If a signal is being received at A
channel, Unit will stay on channel A until the signal disappears. But, if
a signal is being received at B channel, the unit will switch to A
channel to check the signal of A channel every 3 seconds. Even
though a signal is disappear at A (B) channel, which will be remaining
there to check another receiving signal during scan delay time. After
that A (B) channel will be changed to other channel.
If you press the "▲ or ▼" button in dual watch mode, B channel will
move to higher (lower) channel than is currently chosen In dual watch
feature, power save function does not operate.
7. ST(Channel Step), LOCK Option
To enter channel space setting mode press "ST(Channel Step)" button.
This option lets the user select from the following channel steps using
Up or Down button. Channel steps 5KHz, 10KHz, 12.5KHz, 15KHz,
25KHz and 1MHz.
To store the channel step value and enter the normal operational mode
press "ST" button again. Press "FUNC + ST(LOCK)" to lock all the buttons
apart from monitor and function button from taking any action.
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