DCF technology for Arduino with a huge antenna

Projects Networking, Protocols, and Devices
1

There are now very cheap wristwatches with DCF technology on sale. Why is a DCF module for Arduino & Co. so huge? When I see the "antenna" I wonder how a similar function fits into such a small watch.
Does anyone know anything new?

2

You could buy a DCF watch, take it apart and see what is inside.

This is called a "teardown" in the trade. Be sure to make a Youtube video, because others will have the same question.

Here, a guy sacrificed a brand new $500 Starlink satellite dish, just for our edification: Starlink Teardown: DISHY DESTROYED! - YouTube

3

The active part of the Arduino modules are usually very small chip on board and a small external crystal. The large part is the ferrite antenna which can surely be miniaturised.

image
image1061×755 53.4 KB

edit
Conrad DCF77 time signal receiver module

4

Because you are the antenna. The internet was not much use in defining what you mean by DCF technology, but among the many dozen possibilities, I picked the German time signal transmitters. IS this correct?
Paul

5

Hello, you are right. DCF = Discounted Cash-Flow - far away from Arduino. DCF77 is a purely German name for the time signal transmitter. I meant that.

6

I found this:

image

at https://tf.nist.gov/general/pdf/1877.pdf (page 12)

It's not DCF77 but should be similar (WWVB 60kHz)

Incidentally, I am at this moment experimenting with a 20CM ferrite antenna for DCF77.

7

In all cases, the RF signal is only used to make corrections to the time being kept using the crystal oscillator.
Paul