Abstract: A magnetic tape recording/reproducing apparatus for recording video signals on a magnetic tape without providing a guard band between each two adjacent signal tracks. The apparatus comprises a first switching circuit for exchanging 2-channel component signals every nH period to obtain two combined signals each composed of the 2-channel signals which alternate every nH period, two modulators for modulating the two combined signals, a head section having two pairs of rotarty magnetic heads for recording the modulated signals on the magnetic tape so that each two adjacent blocks contain a same channel component signal and for reproducing the recorded signals from the magnetic tape, two demodulators for demodulating the reproduced signals, and a second switching circuit for exchanging the demodulated signals every nH to obtain the 2-channel component signals. With this arrangement, the recording density is remarkably increased and the cross talk interference hardly occur.

Abstract: A recording/reproducing system is provided with a PLL circuit for outputting data pulses and clock pulses on the basis of the read data reproduced from a magnetic recording medium. An external synchronization detection circuit is provided which detects the synchronization data (predetermined zero pattern data), recorded in synchronization areas of the magnetic recording medium, on the basis of the read data. When the synchronization data is detected, the synchronization detection circuit enables the PLL circuit to oscillate in synchronism with the read data. An internal synchronization detection circuit is provided, which detects the synchronization data (predetermined zero pattern data), as recorded in the synchronization areas of the magnetic recording medium, on the basis of data pulses derived from the PLL circuit and the clock pulses. A preventing circuit is further provided.

Abstract: A magnetic disk apparatus has a magnetic head in contact with a flexible magnetic recording medium, for reading out data stored in the recording medium. The magnetic head of the apparatus is of the preceding-erase type. A converting circuit converts the output signal of the magnetic head to digital read data, and outputs it to the PLL circuit. The magnetic disk apparatus includes a preventing circuit for preventing the converting circuit from outputting to the PLL circuit the digital read data which corresponds to read out data from the DC erased areas in the tracks of said magnetic recording medium. The preventing circuit comprises an AGC amplifier for amplifying the signal read out of the magnetic head, a circuit for obtaining an envelope of the output signal of the AGC amplifier, and a circuit for preventing the converting circuit from outputting the read data when the signal level of the envelope is lower than a predetermined value.

Abstract: The present muting control apparatus comprises a first circuit for indicating selection of the error signal relative to N-m (N and m are natural numbers satisfying N>m) data blocks of N data blocks reproduced by a first rotary head when all of the first m data blocks thereof have errors. The first circuit also indicates selection of the error signal relative to N-m data blocks of N data blocks reproduced by a second rotary head when at least one of the first m data blocks reproduced by the first rotary head has no error. The muting control circuit also comprises a second circuit for generating a muting control signal indicating whether to mute the reproduced audio signal, by using error signal which is indicated by the first circuit.

Abstract: A tape recorder comprising a cassette tape compartment for detachably housing a first and second cassette tapes, a capstan for driving the first and second cassette tapes coaxially mounted thereon, a mode selector member for selecting the driving mode for the first and second cassette tapes, operation means for causing the second cassette tape to perform a first or a second function and causing the first cassette tape to perform the first function, a device for allowing the second cassette tape to achieve the first or second function, in response to operation of the operation means corresponding to the first or second function, when the second cassette tape-driving mode has been selected by the mode selector member, a device for allowing the first cassette tape to achieve the first function, in response to operation of the operation means corresponding to the first function, when the first cassette tape-driving mode has been selected by the mode selector member, and a function blocking device for hindering th

Abstract: A reproducing apparatus for reproducing main information from a tape-shaped record bearing medium on which many recording tracks are formed in parallel and additional information recorded along with the main information in a predetermined position within each of a plurality of areas extending in parallel in the longitudinal direction of the medium is arranged to have one operation mode in which the main information and the additional information are reproduced from one of the plurality of areas and another operation mode in which the additional information is solely reproduced from two or more of the plurality of areas.

Abstract: An output signal switching circuit for a video tape recorder which has an RF signal changeover switch which is automatically connected to the output terminal of an RF converter during reproduction mode and the video tape recorder is prevented from being automatically switched when a connecting line is connected to a composite video or base band video signal output terminal, thus assuring that the video tape recorder is easier to operate than prior art systems.

Abstract: In a magnetic head drive apparatus of this invention, a coil of an erasing head is connected to a center point of the coils of a read/write head, and a drive current from a constant-current source is alternately supplied to both terminals of the coil of the read/write head, according to the polarity of the write data. When the read/write head is driven to write data in a magnetic recording medium, the erasing head and the read/write head are driven at an identical timing. In this case, the drive currents for the read/write head and the erasing head are supplied from a single-current source. For this reason, separate constant-current sources are not necessary for the read/write head and the erasing head.

Abstract: In rotating mass memories, for example magnetic disk memories, write or, respectively, read operations are controlled by a static status signal. A plurality of read heads having assigned preamplifiers is selectively activatable with the assistance of a selection signal and is through connectible to a common signal shaping device for further amplification and filtering of the read output signal. The signal shaping device has an input stage assigned thereto in which the differential outputs of the preamplifiers are respectively connected in parallel to the signal shaping device via a respective coupling capacitor. The input stage also comprises first analog switches arranged between an operating voltage and the coupling capacitors and comprises second analog switches in series in the signal lines.

Abstract: A video cassette recorder and taping system is disclosed in which two video cassette decks are included within a single housing. Selection switches are provided so that a prerecorded tape may be displayed from a tape located in one video cassette unit deck while one of a plurality of inputs is being recorded on another video tape located in the deck of the second video cassette unit.

Abstract: For use with master reproducing apparatus which reproduces a visual signal and a corresponding first audio signal, apparatus for substituting a second higher quality audio signal reproduced by slave reproducing apparatus for the first audio signal during reproduction of the visual signal and the first audio signal, includes a synchronizer detector for detecting the amount of synchronization between the first and second audio signals in response to the first and second audio signals and for producing an error signal corresponding thereto; a controller for controlling the slave reproducing apparatus in response to the error signal, to bring the first and second audio signals into synchronization; and a switch for switching the first audio signal to a sound system when the first and second audio signals are out of synchronization, and for switching the second audio signal to the sound system when the first and second audio signals are in synchronization, in response to the controller, whereby the higher quality

Abstract: A video tape recorder for recording a plurality of skewed recording tracks on a video tape includes a recording head, an auxiliary head and an erasing head mounted on a rotary body of a tape guide drum about which the tape is helically wrapped, a rotary transformer for transmitting signals to the recording head, auxiliary head and erasing head rotating with the rotary body, an erase signal generator for generating an earsing signal to be supplied to the erasing head by way of the rotary transformer, and a short circuit arrangement coupled to a signal path connected with the auxiliary head for short circuiting the latter upon applying the erasing signal form the erase signal generator to the erasing head by way of the rotary transformer.

Abstract: An information recording system comprising a read/write device including a read/write head for reading and writing information from and on a rotatable data-storage medium rotated by a first drive motor, and electrically operated elements such as a second drive motor for moving the read/write head relative to the data-storage medium, reading and writing amplifiers, and detectors for sensing operating conditions of the recording system such as the angular position of the data-storage medium. Electric power is supplied to such electrically operated elements from a power source via power disconnect switches connected between the power source and the respective electrically operated elements for selective power supply to the individual elements.

Abstract: Pulse code modulated signal apparatus has a recording mode and a reproducing mode and comprises input terminals for respectively receiving input signals, a digital-to-analog converter for receiving a reproduced digital input signal in the reproducing mode and producing an analog output signal corresponding thereto, and switch circuitry for making a selection of the input signals, the analog output signal and a non-signal and producing a switched output corresponding thereto. A filter filters the switched output. A control circuit controls the switch circuit in the recording mode to select one of the input signals and in the reproducing mode to select alternately the analog output signal and the non-signal, thereby providing aperture compensation.

Abstract: A head swtiching signal producing circuit produces a head switching signal by electrically compensating for a phase error on a rotational plane of a rotary drum between a mounting position of a rotary head on the rotary drum and a mounting position of a rotational phase detector which is used to detect a rotational phase of the rotary drum, so as to produce an accurate head switching signal without controlling the mounting position of the rotational phase detector within a small tolerance.

Abstract: A flexible magnetic disk drive is disclosed which has a disk drive motor for imparting rotation to the magnetic disk under the control of a "motor on" signal, and a stepping motor capable of stepwise rotation in response to stepping pulses for transporting a transducer head or heads radially of the magnetic disk for track to track accessing. Connected to the transducer heads for processing data transferred between them and the magnetic disk, a read/write circuit is connected to a supply terminal via a switching transistor. This switching transistor has connected to its base a switch control circuit for holding the switching transistor nonconductive when the disk drive motor is out of rotation and when the stepping motor is in rotation, and for holding the transistor conductive at least during the progress of data transfer between the transducer heads and the magnetic disk.

Abstract: A method and apparatus permits interfacing of several independent program sources so that a secondary program source is operated in a playback mode while a search mode is engaged for a primary program source. For example, an audio cassette device may be operated in a playback mode while a video cassette device is under the automatic search control of a conventional programmable auto search control unit. The interfacer apparatus of the present invention permits completion of any previously started audio cassette message before playback operation of the video cassette device begins. The method and related apparatus permits maximum retention of the attention span of display users by preventing any significant lapse or gaps in presentation, thereby making the present system particularly suitable for holding the continuous attention of potential customers and students.

Abstract: A signal transmission circuit includes a switched capacitor and a control circuit. The switched capacitor includes a capacitor and a plurality of switching means. The control circuit controls the frequency or level of a control signal to be applied to the switching means of the switched capacitor. By varying the frequency of the control signal with the control circuit, the equivalent resistance of the switched capacitor can be varied. By controlling the level of the control signal with the control circuit, at least one of the plurality of switching means is held in the "off" state thereof, to substantially inhibit the signal transmission of the switched capacitor.

Abstract: A floppy disk driving circuit comprises a memory circuit for storing a plurality of items of delay time of a pair of erase heads from the switching-ON and the switching-OFF of a read/write head for all the tracks of a floppy disk, a control circuit responsive to the memory circuit for controlling ON- and OFF-delay timing of the pair of erase heads based on the plurality of items of delay timing. The plurality of items of suitable timing are previously calculated in connection with the respective tracks of the disk and stored within the memory circuit.

Abstract: Circuit means for recorders in which the same external pin receives a play signal, a record signal, and a noise reduction signal generated by a user. The circuit means is comprised of a differentiating means for receiving the play and record signals and differentiating between them. A memory means is connected to the differentiating means and stores an indication of the last received of the signals. A first switch means is connected to the memory means and is operable to a first condition to control the play function when the memory means indicates the play signal was last received and to a second condition to control the record function when the memory means indicates the record signal was last received. A second switch means is connected to the external pin receiving the noise reduction signal and generating an ouptut signal to turn on noise reduction means during either the play or record mode.

Abstract: A magnetic disc reproducing apparatus for reproducing analog or digital information signals selectively recorded in a plurality of tracks of a magnetic disc includes a transducer placed in transducing relation with the plurality of tracks for reproducing the information signals recorded in one of the tracks, a checking circuit connected to the transducer for checking a portion of the reproduced information signals and an identifying circuit connected to the checking circuit for identifying whether analog or digital information signals are being reproduced.

Abstract: In an apparatus having a record mode for recording video or other information signals in successive parallel information tracks on a record tape by means of a plurality of rotary heads repeatedly scanning across said tape and having respective gaps with different azimuth angles, and in which the apparatus is changeable to a playback mode for causing each of said heads to provide a respective output when it is scanning an information track in which information signals have been previously recorded by a head with a gap having the same azimuth angle; clogging of one or more of the head gaps which would prevent further recording is detected, in the playback mode, by switching from one to another of the outputs of the heads during each period required for the scanning of the tape by each of the heads, detecting the levels of the head outputs during such switching therebetween, and operating a clog indicator when the detected levels of the head outputs are insufficient during the scanning of the tape by each of the

Abstract: A portable tape recorder for remote location news-gathering including a rugged metal housing having operating controls and input-output connections located at one end for ease of access. An audio output suitable for direct interconnection to telephone circuitry is provided in addition to internal speaker and external headset audio output connections. A talk-over preamp operatively interconnects the microphone or other audio input to the recorder output when the recorder is in the pause mode facilitating the use of the recorder microphone for direct telephone line connection. This permits live reporter commentaries, introductions, or `wrap-arounds` to be conveniently interspersed with pre-recorded news story segments. The speaker audio output is muted in the talk-over mode to preclude acoustic feedback while reporter `side-tone` monitoring is available through the external headset or telephone handset connections.

Abstract: A video tape recorder which is capable of reproducing video signals from either of the VHS system and .beta. system tape cassettes. The video signal recorded on a magnetic tape of either one of the VHS system or .beta. system tape cassettes can be recorded on the magnetic tape of the other type tape cassette and reproduced therefrom.

Abstract: A position control system for controlling a motor-driven mechanism capable of occupying a plurality of specified positions comprises a plurality of switches for specifying a position to be occupied by the mechanism and an encoder for generating a specified position signal representative of the specified position and a loading circuit for providing a present position signal representative of the position presently occupied by the mechanism. A read-only memory circuit uses the specified and present position signals to provide a control signal for controlling the motor to move the mechanism to a particular position and a comparison signal and a particular position signal indicative of that particular position. A position detector responsive to the position of the mechanism provides a detection signal representative of the particular position when the mechanism reaches it.

Abstract: A tape player with a built-in radio for a car, includes a station selection circuit and a tape scanning circuit. A single group of preset switches for selecting a desired station as well as a desired piece of music recorded on the tape is connected to both circuits. A change-over switch is provided for selectively changing over from one of the station selection circuit and tape scanning circuit, to the other. A switching circuit such as a gate circuit, for rendering one circuit inoperative and placing the other in a waiting state for operation in response to the change-over operation of the change-over switch, is also provided, so that manipulation of each preset switch of the group of preset switches, operates either the station selection circuit or the tape scanning circuit, which is kept in the waiting state for operation. The change-over switch is activated by loading a tape, to switch from the station selection circuit to the tape scanning circuit.

Abstract: A mode switching mechanism comprises a driving toothed wheel driven by a motor, a driven wheel having first and second coaxially mounted cams for rotation therewith, a toothed circumferential portion for providing meshing contact with the driving wheel and a toothless circumferential portion for providing out of meshing contact with the driving wheel. The driven wheel is normally urged so that it comes into meshing contact with the driving wheel. A spring-biased rotatable trigger lever is arranged to lock the driven wheel in a position out of meshing contact with the driving wheel and unlock it in response to the operation of any one of tape operating mode keys to establish the meshing contact to thereby allow the driven wheel to be rotated by the driving wheel.

Abstract: An apparatus for processing an audio stereo signal having left and right channels, for use with a video tape recorder having a monoral audio head comprises an analog switch assembly having an electronically controlled switch for each audio channel. A line connects the audio switch assembly to the monoral audio head and control equipment is connected to a video signal terminal of the VTR or video tape recorder. The control equipment utilizes a horizontal sync or synchronization pulse to produce a pair of complementary control pulses. The horizontal sync pulse is processed in a pulse multiplier to step up the frequency to at least twice and preferably about four times the highest audio signal frequency. By alternately controlling the electronically controllable switches to provide a sample of first one and then the other channel, a composite stereo signal can be recorded and then reproduced using the monoral audio head.

Abstract: A video disc recording and reproducing system in which a program is stored on a video disc to eliminate the need for the user to manually input a control program. A program and control signal is recorded in place of at least a portion of one of two audio tracks on a video disc along with video signals. The video disc player of the system includes modulator circuits which demodulate the video and audio signals from the disc, a central processing unit connected to the output of the demodulator circuit for demodulating the audio signal for detecting the control signal and program recorded on the video disc, and a memory for storing the control signal and program. The central processing unit controls the memory for storing the program and control signal at predetermined locations corresponding to the state of the control signal.

Abstract: A floppy disc device having a read/write head, a pair of erase heads and a delay mechanism for delaying the operation of the erase heads with respect to the operation of the read/write head is provided. The pair of erase heads is provided in the downstream direction of the read/write head with respect to the movement of a floppy disc recording medium, thereby avoiding cross coupling between the read/write and erase heads. In accordance with one aspect of the present invention, the delay mechanism delays energization and deenergization of the erase heads with respect to those of the read/write head. Another aspect of the present invention is that the delay mechanism delays energization of the erase heads with respect to energization of the read/write head for some of a plurality of concentic recording tracks. The present invention made it possible to carry out proper tunnel-erasing without under-erasing and/or over-erasing.

Abstract: A record/reproduce circuit for VTR comprising two normal reproducing heads with different azimuth angles, a special reproducing head with the same azimuth angle as that of the one normal reproducing head, a rotary transformer through which signals from these heads are supplied to a static circuit section, a change-over means for alternately switching a signal from the special reproducing head and a signal from the other normal reproducing head with a different azimuth angle from that of the special reproducing head, a feedback type preamplifier for amplifying the output of the change-over means, and another feedback-type preamplifier for amplifying a signal from the normal reproducing head with the same azimuth angle as that of the special reproducing head.

Abstract: A signal copy device for a digital record/reproduction system includes an encoding circuit for producing a first digital encoded signal corresponding to an analog audio signal. The encoding circuit is connected to a first VTR through a switch section of a switch circuit and a first digital signal processor. A second VTR reproduces and generates a digital encoded audio signal to be copied. The switch circuit is connected to the encoding circuit and the second VTR. The switch circuit includes two switch sections which operate in cooperation with each other. When a reproduction signal is generated from the second VTR, the two switch sections are switched. The reproduction signal is supplied to the first VTR through these switch sections, thus accomplishing copying.

Abstract: An electronic switching circuit coupled between a magnetic head driving circuit and transducing windings utilizing an electronic switch whose internal resistance changes substantially linearly in response to an increasing or decreasing control signal. Particularly useful in magnetic bias recording or erase circuits to eliminate erase of useful information and recording of disturbing noise spikes due to induced high frequency noise signal when the switch is activated.

Abstract: A tape recorder with a cue signal recording function is arranged to record input signals on corresponding recording tracks of at least two channels, at least one of which is also utilized as a track for cue signal recording. When the cue signal is not being recorded, the cue signal recording track is utilized for recording a given input signal other than the cue signal, in cooperation with recording of other input signals on recording tracks other than the cue signal recording track. During recording of the cue signal on the cue signal recording track, the given input signal is recorded on one of the other recording tracks.

Abstract: A magnetic tape recording and playback apparatus, selectively changeable between recording, playback, and stop modes, includes a recording/playback transducer, a line amplifier connected during recording to amplify the signal to be recorded by the transducer and during playback to amplify the signal picked up by the transducer; a power amplifier to amplify the signal provided by the line amplifier to drive an acoustic transducer; and a level indicator for selectively indicating the output level of the line amplifier and of the power amplifier. A switch circuit automatically connects the level indicator to the line amplifier when the recording mode is selected and to the power amplifier when either the playback or stop mode is selected. When the apparatus is in the playback mode, the level indicator can be coupled to the line amplifier by actuation of a push button or other manual switch.

Abstract: In a recording apparatus for performing magnetic recording onto different parts of a magnetic recording medium as it runs in sequence, a switching element is connected in series in a signal path to a magnetic head which is connected to the output of the signal amplifier and to a bias oscillator. Accordingly, the signal current flowing to the magnetic head can be interrupted. A delay circuit is provided for controlling the operation of the switching element so as to defer initiation of the signal current flow to the magnetic head. This is done pending attainment of the speed of movement of the magnetic recording medium to a substantially constant level after the magnetic recording starts. Connected in parallel to the switching element is a by-pass circuit of which the impedance is relatively low at a frequency equal to that of the bias supplied to the magnetic head. A stabilized muting effect from the low to the high sound region thus can be produced.

Abstract: Apparatus is provided wherein signals which are reproduced from a record medium and which are supplied to head-phones are selectively attenuated and, concurrently, audio electrical signals produced by a microphone are superimposed onto these attenuated signals. An attenuator is coupled between a record/playback transducer and an amplifier; and a switch exhibits a first condition to short-circuit the attenuator, and a second condition to enable the attenuator to attenuate the signals reproduced by the record/playback transducer and also to superimpose the audio electrical signals produced by the microphone onto the attenuated signals. In one embodiment, a record/reproduce selector selectively establishes either a recording mode, whereby the audio electrical signals produced by the microphone are amplified and supplied to the record/playback transducer, or a reproducing mode, whereby the signals reproduced from the record medium by the record/playback transducer are supplied to the amplifier.

Abstract: A two speed or multi-speed video tape recorder of the conventional helical scan type in which the audio signal is capable of being recorded as a time compressed signal at one end of each helical video scan, or alternatively, in conventional longitudinal fashion by means of a stationary magnetic head engaging one edge of the tape.At low tape transport speeds, improved bandwidth (and therefore sound fidelity) is obtained by use of the time compression technique; while at higher transport speeds, there are advantages in utilizing the stationary audio head.Circuitry is provided to automatically utilize the time compression technique at lower tape transport speeds and the stationary head longitudinal recording technique at higher tape transport speeds.

Abstract: A photographic still provided with a magnetizable coating is inserted into a recording/playback device provided with a movably mounted head unit having a set of heads. A rotary motor drives an endless belt in a single direction, the upper and lower runs of the belt always travelling in opposite directions. The head unit is alternately coupled to the upper and to the lower run of the belt, for travel in one and then the opposite direction. Upon each reversal of the travel direction of the head unit, a successive one of the magnetic heads is activated, so as to track a meandering track on the magnetic coating.

Abstract: A magnetic tape device having two independently operative tape transports incorporated in one common deck which comprises means for selectively performing recording by a first transport in combination with reproducing by a second transport and reproducing by the first transport in combination with recording by the second transport, and means for recording a reproduced signal from either one of the transports on the other transport through a common reproducing and recording process circuit, thereby to effect dubbing in either direction.

Abstract: A portable paging device comprises a beeper portion for real time listening of a received message and a magnetic tape recorder for recording a received message and playing it back at the convenience of the recipient. After a message has been recorded, an indication is given which may be reset after the message has been played. Means are provided to disable the tape recording portion of the device if an end of tape signal has been generated or if there is no tape in the tape recording portion.

Abstract: Multichannel magnetic heads are connected to record and reproduction signal lines through electronic switching elements. The electronic switching elements are successively switched by the switching control signals to be successively connected to said magnetic heads.

Abstract: A recording/playing circuit includes a noise reduction circuit, a switching circuit and a control circuit. The noise reduction circuit includes a pre-amplifier, a combining network, an inverter circuit and a side chain. The switching circuit has first, second and third input positions and an output terminal. The first input position is coupled to the output of the pre-amplifier, the second input position is coupled to the output of the inverter circuit, and the output terminal is coupled to the side chain. The third input position is connected to a muting circuit. The control circuit controls the switching circuit so that one of the electric signals applied to the first, second and third input positions of the switching circuit may be selectively transmitted to the output terminal of the switching circuit.

Abstract: A mode switching circuit has external terminals, a mode selection means for selecting a mode in accordance with the kind of a signal applied to the terminals, and a means for designating a mode selection state in the mode selection means by a mode selection signal. The external terminals are used commonly for a plural kinds of signals.

Abstract: A microphone sensitivity-changing apparatus used with a tape recorder whose recording or playback mode can be paused and whose microphone has its sensitivity changed in accordance with the object for which said tape recorder is applied, the improvement being that a first switch for instructing the pause mode and a second switch for instructing the changeover of the sensitivity of the microphone are operated interlockingly with each other.

Abstract: A switch set in the power supply section of a microphone is actuated at the initial stage of the slide of an operation button which is carried out to shift a tape recorder operation from the recording mode to the stop mode. The switch is actuated at the terminal stage of the slide of the operation button which is carried out to changeover the tape recorder operation from the stop mode to the recording mode. Therefore it is possible to eliminate the unnecessary recording in the built-in microphone of noises disagreeable to the ear of the user which are caused by, for example, the slide of the operation button.

Abstract: A pulse-operated mode switching mechanism for tape recorders comprises a single solenoid operated in response to a pulse of different periods depending on the function of the operating key. A rotary wheel is driven by a motor to provide a 360.degree. revolution in response to the energization of the solenoid. Electromagnetic transducer heads are mounted on a carrier plate which is movable between a first position in which the heads are remote from the tape and a second position in which the tape is in contact with the heads. The carrier plate is moved from the first to second position by the rotation of the rotary wheel when the solenoid is energized for an interval greater than a first predetermined interval and returned to the first position in response to the energization of the solenoid. During playback or recording mode the solenoid is energized for an interval greater than the first predetermined interval so that the transducer heads are brought into contact with the tape.

Abstract: Apparatus for compensating for the absence of signals among a plurality of correlated signals, which occur simultaneously and which have carrier components, is disclosed herein. Such apparatus comprises detector means responsive to the absence of the carrier for longer than a predetermined time for selectively connecting output signals from channels where the carriers are present to the outputs of those channels where carriers are absent. The apparatus of the invention operates in real time without delay devices. Preferably, the invention is embodied in an apparatus for reproducing magnetically recorded, stereophonic signals, functioning to prevent dropouts from affecting the quality of the output signals and the sound corresponding thereto.

Abstract: A recorder for the recording and the playback of analog information on a movable magnetic medium, e.g. a magnetic tape, has a limiter for reducing the gain of the record section in response to excessive input amplitudes, has a playback section that cancels noise which the transducer unit picks up, and has a muting circuit that diminishes playback gain during certain operations.The recorder applies the limiting function to the compressor portion of a dynamic compandor and applies the muting control to the expandor portion of the compandor.The noise cancellation introduces a relative phase reversal to noise present with different playback signals, and sums selected portions of those signals to cancel the noise.

Abstract: A device for compensating for an inequality between the d.c. magnetic fields set up by the two oppositely acting windings, respectively, of the magnetic heads of a data storage device, particularly a disc memory, and a data storage apparatus including such a device, the device comprising means for generating a compensating direct current and feeding this current at the appropriate time to a predetermined one of the two windings of the magnetic heads. The magnitude of the compensating direct current is advantageously adjusted in dependence on the instantaneous magnitude of the write current.