Abstract: In a digital tape recording system for video and sound signals, in which information in each track is stored in plural sectors having synchronizing preambles that aid in synchronizing the playback of the information, special preambles containing a frequency component that is lower than normal are used for the first sector of the first track in each video frame or field. The normal and special preambles are produced by passing the binary code". . . 01010101 . . . " (in the case of all but the first sector of each frame or field) or ". . . 011011011011 . . . " (in the case of the first sector) through a Miller Channel Code encoder to produce, in the first case, a synchronizing square wave fluctuating at one-fourth the bit presentation frequency, and in the second case, a synchronizing square wave fluctuating at one-sixth the bit presentation frequency.

Abstract: An uncorrected composite color television signal, including frequency-modulated luminance and frequency-transposed chrominance components is recovered from a storage medium and separated by filters into its luminance and chrominance components. The chrominance component is coupled to a frequency converter for converting it back to its nominal frequency, i.e., its frequency prior to the frequency transposition. The frequency and phase of the output provided by the frequency converter is determined by a chrominance subcarrier reference signal provided by a generator. The uncorrected luminance component is employed to adjust the frequency and phase of the signal provided by the generator so that the provided reference signal is coherent with the uncorrected luminance component. This causes the frequency converted chrominance component to be stabilized to the reference signal and to be coherent with the uncorrected luminance component.

Abstract: Circuit and method for generating a ramp signal having an incrementally changing slope. The invention is particularly useful for ramping magnetic recording bias or erase signals by providing a relatively slow slope within the non-linear region of the magnetic medium characteristic while providing a relatively steep slope in the linear region to reduce recording of disturbing "pop" signals.