La Crosse Technology RADIO CONTROLLED PROJECTION ALARM CLOCK Instruction Manual page 4

In addition or instead of inserting batteries, the AC adapter can be used:
1. Connect the power adapter to a wall socket
2. Insert the adapter into the jack at the bottom of the clock
3. The Projection clock will now start receiving the DCF time signal. After
approximate 3 to 5 minutes, the DCF time will be displayed
Note: User shall also refer to Manual Setting for detailed Setting up procedures.
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