| 968 / | HD | HOROLOGY |
| 506 | | SYNCHRONIZATION OF INDEPENDENTLY DRIVEN CLOCKS (synchronization between master and slave pendulums subclass 532; synchronization of electronic oscillators in general H03L 7/00) [G04C 11/00] {7} |
| 507 | DD | .~> By changing the driving speed [G04C 11/00B] |
| 508 | DD | .~> By changing the ratio of the driving gear [G04C 11/00C] |
| 509 | DD | .~> By positioning of the index or by regulating the length of the pendulum in dependence on the time difference with a standard [G04C 11/00H] |
| 510 | DD | .~> By radio (time setting brought into action by radio subclass 499) [G04C 11/02] {2} |
| 513 | DD | .~> Over a line (transmitting time signals over telephone networks H04M 11/06; time setting subclass 498) [G04C 11/04] {2} |
| 516 | DD | .~> With direct mechanical action on the time-indicating means (time setting subclass 498) [G04C 11/06] |
| 517 | DD | .~> Using an electro-magnet or -motor for oscillation correction [G04C 11/08] {2} |