Coming at it from the other side, not too hard to make a long-case ('grandfather') clock using the per-second signal from MSF (WWV, DCF etc) to drive the pendulum and so lock the clock to 'atomic' time.
An old 6 volt relay coil worked for me, main issue is needing a local backup oscillator stable enough to cope with period of signal loss/power outages.
Obviously simpler to use GPS 1PPS to derive the drive signal but that's a challenge to pick up with a coil of wire and a capacitor.
An old 6 volt relay coil worked for me, main issue is needing a local backup oscillator stable enough to cope with period of signal loss/power outages.
Obviously simpler to use GPS 1PPS to derive the drive signal but that's a challenge to pick up with a coil of wire and a capacitor.