Abstract: Transmission lines for digital signals may include a large number--for example, several hundred--of intermediate generators. In this case, telemetering units are provided at the end points and at intermediate points, by means of which the digital telemetry signals are generated and sent over the transmission lines together with the digital information signals. In the event of interference, a problem arises, due to the fact that the telemetry signal that is needed to identify the interference is only available after a comparatively long time. Therefore, according to the invention, a method is recommended for the initial synchronization, at bit rate, of the pulse generators which generate the bit pulse in the telemetering units. The pulse generation is accomplished with a phase-control loop which generates a signal pulse with a comparatively high frequency.

Abstract: The delay elements of a signal energy transmission network are divided into separate portions through which the transmitted energy is phase shifted by substantially equal amounts. A phase correction circuit reverses the phase shift through one of the divided delay portions by providing a locked oscillator operating at twice the frequency of the signal at a reference phase angle and subtracting therefrom the input frequency of the signal phase shifted through said one of the divided delay portions in order to maintain a constant frequency vs. phase relationship.