I ran into this YouTube video on how you can amplify the signal for your radio controlled watches: https://youtu.be/wI4FwQMCN9w
In short, the guy in the video said he stumbled on a way to amplify the signal by accident. All you need to do is hang your watch on a metal pipe and it will help it receive the signal successfully and sync. Later on, I found out some people on the internet claim even wearing a watch on your wrist will help it get reception.
As someone living too far away from the German DCF77 transmitter (https://en.wikipedia.org/wiki/DCF77?wprov=sfla1) to ever receive the signal with my radio controlled watch, I found the video useful. By hanging the watch on my bike's handlebar, I got my first sync ever. I also tried syncing it on my wrist once when I was up late and it also worked.
But how does this work? The metal pipe can't add any energy to the signal so it doesn't really amplify anything, does it? And the watch's metal case doesn't really touch the pipe, just the plastic strap, so can it even act as some sort of an antenna or something? So does it just focus the signal somehow? Obviously, I know nothing about radio reception, but I am interested in how this works.
Also, is there a way to increase the reliability of the reception? I still can't receive the signal 100% reliably, even with the metal pipe over night. Would a certain length, shape or material of the pipe help? Maybe orientation?