Question about TFA Radio alarm clock

Works perfectly in Switzerland. As far as I know, the tower is located in Frankfurt

It does not connect to anything, but receives a long-wave transmitter called DCF77, a so-called time signal transmitter, which in turn has an atomic clock as its signal source. Reception is possible over a distance of approx. 3000km with the centre in Germany.

Works very well with the Swiss timetable, is done automatically.

No idea with which atomic clock.
Emofang in Switzerland works perfectly