Abstract: A rotatable guide having both a conical and a cylindrical surface on opposite sides thereof is provided, within a coaxial-reel cassette, for orienting a magnetic tape along two different tape paths, depending on whether the tape is wound within the cassette between the coaxial reels or is withdrawn from the cassette and wrapped around a helical recording drum. By providing such a guide, with appropriate selective orientation, the tape may be translated directly between the reels by means of the conical surface, or guidedly directed to and from the recording drum, about which it helically wraps, by means of the cylindrical surface.

Abstract: A helical-scan tape recorder has a pair of tape wrapping guides, for engaging a magnetic tape and helically placing it around a recording drum, which are mounted on a pair of coaxial ring gears. Each guide is biased for cooperation with the ring gear upon which it is mounted. By providing a stop member on the recorder to intercept and restrain the yieldable guides, against their bias and before the ring gears stop, any "play" in the gearing is taken up and the guides are optimally and accurately positioned for precisely placing the span of tape around the drum.

Abstract: Time base instability of signals in a train thereof is corrected by use of analog shift registers. As employed in the correction of time base instability of video signals, plural analog shift registers are used. The same clock rate is used, respectively, to clock video signals into and out of analog shift registers. The clock rate is set so that samples of a video signal which has a normal duration may load all stages of an analog shift register within the duration of the normal signal. Thus, samples of a stretched signal fully load all stages of the analog shift register, the trailing part of such stretched signal being discarded. Conversely, a video signal which has been compressed, although being fully loaded into the analog shift register, loads less than all of the analog shift register stages.

Abstract: Time base instability of signals in a train thereof is corrected by use of analog shift registers. As employed in the correction of time base instability of video signals, plural analog shift registers are used. Two clock rates are used, respectively, to clock video signals into and out of the analog shift registers. The clock-in rate is set so that samples of a video signal which has been stretched a predetermined amount may load all stages of an analog shift register within the duration of the stretched signal. The clock-out rate is set to unload all stages of an analog shift register within the nominal duration of a video signal.