Abstract: A device for producing a switching pulse used to compensate for dropout in a video signal received from a recording apparatus and for compensation of time error in the video signal, comprising, a manipulated variable producing device within the recording apparatus, a transit time section having an input connected to the recording apparatus for receiving the video signal produced thereby and the manipulated variable and a dropout recognition device having an input connected to the recording apparatus for receiving the video signal and an output connected to the input of the transit time section. The dropout recognition device produces a flag signal which corresponds to a dropout which may occur in the video signal. The output of the dropout recognition means containing the flag signal is connected to a first switching device which, in turn, is connected to the input of the transit time section for forming a marking pulse which has the duration of the flag signal in the video signal.

Abstract: The disclosure is an improvement in a three-line sequential transmission system for a color television signal, particularly for recording, and where the sequential signal is transformed again, during reproduction with a series-connection of line delay lines, into three simultaneous color signals, and a luminance signal is obtained by composing the signals from several successive lines. In accordance with the disclosure, the luminance signal has an amplitude ratio between these signals, to increase the picture sharpness in the vertical direction, such that the amount of the luminance transmission function of the entire system, including recording and reproduction, at the frequencies (n+1/2)f.sub.H is substantially equal to those of the frequencies n.multidot.f.sub.H where n=0, 1, 2 . . . and f.sub.H is the line frequency. The composition is effected such that zeros appear in the low frequency range of the transmission function at the frequencies (n.+-.1/3)f.sub.

Abstract: In a playback circuit for a three-line sequential color television signal, which includes a memory presenting four outputs providing, respectively, the undelayed sequential signal and the sequential signal delayed by one, two and three horizontal picture line scanning periods, a combining arrangement connected to the four outputs to combine the signals thereat into a difference signal, and a further combining arrangement for adding the difference signal to the original three-line sequential signal, the circuit is simplified by constructing the memory to cause the signals at its four outputs to have identical amplitudes and by combining the signals at the four outputs of the memory by means of four electrically identical combining components, the undelayed sequential signal and the signal delayed by three picture lines having their polarities reversed relative to the signals delayed by one and two picture lines.

Abstract: A grinding foil which is to be used for grinding a record cutting or playback stylus is manufactured by providing a surface layer of a plastic foil with indentations for accommodating a grinding agent in granular form, filling the indentations with such grinding agent, and thermoplastically deforming the surface layer to smooth the foil surface and to bond the grinding agent into the surface layer.