[michaelt]

Experiences with these things vary a lot, depending on your location, the construction of your home, and (I assume) the cost of the receiver.

I had a ~$15 radio-synchronised clock when I was quite a long way from the transmitter, in a solid brick building. It would get a signal in some locations and orientations in the building.

I don't have firm information on how good the signal reception was, as of course it would keep ticking even if it didn't have a signal.

[layer8]

Just to clarify, I always lived in solid-brick/concrete buildings and never had issues with DCF77 clocks (and never heard of anyone having issues), which usually cost in the 15-30 € range. It’s an inexpensive technology that just works, at least in Western Europe.