Abstract: A simple and inexpensive demagnetizer for the magnetic heads of a tape cassette recording and/or reproducing device includes an intermediate gear which is rotated by either one of two hub gears engaging respective drive spindles of the recording and/or reproducing device. A push-pull rod has one end pivotally connected to an outer radial position of the intermediate gear and another end pivotally connected to a source of alternating magnetic field of constant intensity. Rotation of the intermediate gear causes the magnetic field generator to be cylically and linearly reciprocated with respect to the head so as to produce a decreasing magnetic field at the head.

Abstract: A cleaning apparatus for cleaning the heads of tape player/recorder units in which, when the cleaning apparatus is operably loaded into the unit, movement of the pinch roller and capstan of the unit turns a cleaning element positioned against the head. Transmission of the rotary movement of the pinch roller and capstan is achieved by a rotatably mounted drive belt connected to a cleaning element, such as a felt pad, so that as the pinch roller and capstan rotate, the belt is driven, thus causing the cleaning element to be rotated against the head about an axis substantially perpendicular to the plane of the face of the head of the unit. A tape drive cleaning assembly is included which cleans the pinch roller and capstan of the unit when the cleaning apparatus is turned upside down.

Abstract: An improved video synchronizing signal separator for separating luminance and synchronizing signal components, respectively, from a composite video signal. Separate luminance and synchronizing channels are supplied with the composite video signal, each channel including a biased diode and an output attenuator. The diodes are poled in opposite directions to conduct when the particular threshold level established by the bias voltage applied thereto is exceeded. As an example, the diode in the luminance channel may be positively poled to conduct when the luminance signal component exceeds a positive threshold level and the diode in the synchronizing channel may be negatively poled to conduct when the synchronizing signal component exceeds a negative threshold level. The positive-going luminance signal component serves to cut off the diode in the synchronizing channel and the negative-going synchronizing signal component serves to cut off the diode in the luminance channel.