Buying a radio-controlled alarm clock: what to look for
A good radio-controlled alarm clock shows the exact time, adjusts itself when the clocks change and is easy to read at night, too. When buying one, pay particular attention to digit size, lighting, alarm functions, additional displays and power supply. Here are the most important criteria, with examples from the ADE range.
Key facts at a glance
- Radio-controlled alarm clocks set themselves automatically via the DCF77 time signal – including the switch to summer and winter time.
- The digit height determines readability: for the ADE radio-controlled clocks presented here, it ranges from 19 mm (CK2112) to 110 mm (CK2302).
- Two alarm times are practical for weekdays and weekends or for couples with different wake-up times.
- Lighting at the push of a button or via a light sensor ensures that you can read the time at night.
Radio reception: the right time automatically
Radio-controlled alarm clocks receive the DCF77 time signal from Mainflingen near Frankfurt am Main. On 77.5 kHz, it transmits the official time of the Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, and has a range of around 2,000 km. This allows the clock to set itself and switch automatically between summer and winter time.
Make sure that the time can also be set manually if needed, for example in places with weak reception. This is possible with the CK1703 radio-controlled alarm clock and many other ADE models. For good reception, place the alarm clock close to a window and about 1 to 2 meters away from electrical appliances.
Display and size
Think about the distance from which you want to read the time. On the bedside table, compact models are sufficient; for people with impaired vision or for the wall, large digits make sense. You can find the digit height in the technical data of each model.
| Model | Digit height | Lighting | Alarm times | Additional displays |
|---|---|---|---|---|
| CK2112 radio-controlled alarm clock | 19 mm | 8 sec. at the push of a button or via light sensor | 2 | Temperature, humidity, date |
| CK1703 radio-controlled alarm clock | 26 mm | 5 sec. via large button | 1 | Temperature, date |
| CK2406 radio-controlled clock with projection | 29 mm | Day and night light sensor | 2 | Indoor and outdoor temperature, date |
| CK2303 table and wall clock | 46 mm | approx. 10 sec. at the push of a button | 2 | Temperature, humidity, date |
| CK2113 radio-controlled clock | 51 mm | approx. 8 sec. at the push of a button | 2 | Temperature, humidity, date |
| CK2301 wall clock | 67 mm | approx. 8 sec. at the push of a button | 2 | Temperature, humidity, date |
Many models such as the CK2113, CK2301 and CK2303 can either stand on a surface or be hung on the wall. For travel, a compact alarm clock like the CK2112 is a good choice.
Lighting
- At the push of a button: The display lights up only briefly, for 5 to 10 seconds depending on the model. On the CK1703, a large button on the top activates the light and the snooze function at the same time.
- With light sensor: The CK2112 radio-controlled alarm clock switches the lighting on automatically when it gets dark. On the CK2301, a brightness sensor can optionally be activated.
- Without lighting: Some radio-controlled clocks such as the CK1702 and CK2302 have no display lighting. If you want to look at the clock at night, choose an illuminated model.
Alarm functions
- One or two alarm times: With the CK2303 table and wall clock, you can set two alarm times for Monday to Friday, Monday to Sunday or Saturday and Sunday.
- Snooze function: On many models, the snooze interval is 5 minutes; on the CK2303, the length is adjustable.
- Alarm via slide switch: On the CK2112 and the analog radio-controlled alarm clock CK2022, you switch the alarm on or off with a switch.
- Alarm sound: On the CK2022, the alarm gets louder over 2 minutes. Whether the volume can be adjusted is stated in the technical data of the respective model.
Additional displays and projection
All radio-controlled alarm clocks mentioned here show the room temperature, in °C or °F. Models such as the CK2113, CK2301 and CK2303 also measure humidity in the range of 20 to 95 %, and the CK2112 displays it as well. This helps you air your rooms properly. On many ADE models, the date and day of the week appear in 7 languages (DE, DK, EN, ES, FR, IT, NL). If you want to monitor the indoor climate more closely, you will find suitable devices among the hygrometers.
A projection is practical if you don't want to reach for the bedside table at night. The CK2406 digital radio-controlled clock with projection projects the time and temperature onto the ceiling or wall. The projection arm swivels, and the projection can be rotated by 180°. An outdoor sensor for the outdoor temperature and a USB charging function are included.
Power supply
Most ADE radio-controlled alarm clocks run on batteries, which are included in the delivery. This means you can place the alarm clock independently of a power socket and have no cable by the bed.
- 2 × AA: CK1703, CK2112, CK2113, CK2303
- 2 × AAA: CK2301
- 1 × AAA: CK2022
- 4 × AA: CK2302
Tip: After a battery change, the clock searches for the radio signal again. Ideally, place it by the window overnight for this. You can find the steps for your model in the user manuals.
You can find all radio-controlled alarm clocks and radio-controlled clocks from ADE, the Hamburg heritage brand since 1935, in the Clocks and alarm clocks category.
Matching products
From this article
What should I look for when buying a radio-controlled alarm clock?
What matters is an easy-to-read display, lighting for the night, the right number of alarm times and a snooze function. It is also worth looking at the temperature and date display as well as the power supply.
How large should the digits on a radio-controlled alarm clock be?
That depends on the distance and your eyesight. For the bedside table, compact displays are enough for many people; if you want to read the time without glasses or from a greater distance, choose large digits, such as 46 mm on the CK2303 or 67 mm on the CK2301.
Does a radio-controlled alarm clock also work abroad?
The DCF77 time signal can be received within a radius of around 2,000 km of Mainflingen near Frankfurt am Main, i.e. in large parts of Europe. Outside this range, you set the time manually.
Does a radio-controlled alarm clock need a power socket?
No, most ADE radio-controlled alarm clocks run on batteries, for example the CK2112 and CK2303 with 2 × AA. This means you can place them flexibly.
What are the benefits of two alarm times?
With two alarm times, you can for example set one time for weekdays and one for the weekend, or wake two people at different times. Models such as the CK2112, CK2113, CK2301 and CK2303 offer this function.
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