Abstract: A test control circuit includes a channel selector circuit and input and output buffers, which cooperate with input/output buses and respective latches of the multichannel apparatus, to allow an operator to select one or more input buses, and one or more output buses, of a respective channel or channels of the multichannel apparatus. Thus the circuit allows selectively applying an input test signal to one or more channels via the front of the apparatus, while selectively monitoring the resulting output signal from the channel or channels also via the front of the apparatus. An exemplary purpose of the test control system is to facilitate the channel alignment and head azimuth adjustment of, for example, a multichannel audio tape recorder.

Abstract: A system for transmitting an audio signal in pulse width modulated form on a video signal is disclosed. The audio signal is modulated by varying the time occurance of at least one edge of a pulse as a function of the voltage level of said audio signal at a selected time. The pulse is then added to the video signal during each horizontal blanking interval. Upon receipt of the transmitted signal, the video signal is processed to reform said edge varying pulse. An output pulse is then generated for each varying edge of said pulse, whose pulse width is a function of the time of occurance of said edge with respect to a stable reference edge. This output pulse is then used to generate a voltage signal whose level is determined by the pulse width of said output pulse. The successively generated voltage levels comprise the reformed audio signal.

Abstract: Filters are coupled to receive an uncorrected composite color television signal, which signal has been subjected to recording and reproducing operations and processed to have incoherent luminance and chrominance components, with the chrominance component color corrected. The filters separate the composite signal into its luminance and chrominance components. The chrominance component is coupled to a decoder to prepare it for subsequent encoding relative to a chrominance subcarrier reference signal that is coherent with the luminance component. The chrominance subcarrier reference signal is provided by a generator that is frequency and phase adjusted relative to the luminance component. A following encoder receives the decoded chrominance component and reference signal. The encoder responsively operates to provide a newly encoded chrominance component stabilized to the reference signal. This causes the newly encoded chrominance component to be coherent with the luminance component.

Abstract: To provide measurement of horizontal and vertical spatial errors, as well as shading errors, the active video picture is divided horizontally into 13 equal blocks, and vertically into 14 bands of checkers. During the setup mode, the signal from a selected camera is fed to an A/D converter in the video signal path, and to sync and pattern validation circuits which provide control and timing signals and an electronic test pattern signal. Horizontal error measurement is provided via a horizontal adder/memory loop whereby selected samples within the blocks of successive horizontal lines are selectively summed to provide successive pairs of summed horizontal digital data. Vertical error measurement is done simultaneously by a vertical adder/memory circuit whereby selected adjacent samples of alternate checkers are selectively delayed and added, to provide successive pairs of summed vertical digital data.

Abstract: The checkered black/white test pattern used during a television camera setup mode for the automatic correction of spatial registration, shading, and gamma errors, is also used to obtain digital data for automatically focusing the camera. The system detects the variation of the optical and the electrical focus by detecting the corresponding variation in the risetime of the signal generated as the electron beam spot scans across a transition in the test pattern. At an optimum focus condition the digital data is at a maximum value, i.e., the risetime is at a maximum rate. The focus data is stored for subsequent use during the camera operating mode.

Abstract: A method and apparatus for detecting errors in the accuracy of multi-bit data words, i.e., a parity method and apparatus, is disclosed. The invention is intended for use in determining the accuracy of multi-bit data words that are being transmitted through a communication channel or are being recorded and reproduced using magnetic recording or other technique.

Abstract: Highly orientable acicular iron particles are made by reducing an acicular ferric oxide in powder form by contacting the granular acicular ferric oxide with hydrogen in the presence of a dehydrating agent selected from calcium hydride, calcium, calcium carbide, and mixtures thereof.

Abstract: In an apparatus for automatically maintaining a transducing head assembly on the proper track, which is particularly adapted for a helical scan recording and/or reproducing apparatus capable of providing special motion effects, an automatically compensated movable head servo is disclosed. The apparatus is of the type which utilizes transverse positioning of the transducing head assembly to accurately follow a track during reproducing and, at the completion of the reproduction from the track, to properly position the head in position to either reproduce the next adjacent successive track, reproduce the same track or reproduce another track so that the appropriate special motion effect is achieved. Proper tracking is maintained by applying a small oscillatory motion to the head to cause it to vibrate laterally of the track, examining the resulting modulation of the reproduced signal's envelope to generate a tracking error correction signal and applying the error correction signal to the head assembly.

Abstract: The process provides practical manufacture of a two-piece, dielectric filled, ferrite toroid assembly while providing optimum electromagnetic characteristics presently not consistently available by manufacturing the toroid in a pressed one-piece configuration. A pair of complementary ferrite blanks of selected shapes are machined to dimension, and the mating surfaces thereof are selectively lapped. The complementary ferrite parts are then permanently assembled about a pre-machined dielectric insert, and the composite toroid is secured together by a selected adhesive selectively disposed therein.

Abstract: Highly orientable acicular iron particles are made by reducing an acicular ferric oxide which has been formed into a porous matrix by combining it with sodium tripolyphosphate and reducing the oxide with hydrogen in the presence of a dehydrating agent.

Abstract: Apparatus is disclosed for providing compensation for missing, incorrect or otherwise defective data in a data stream preferably comprised of video information. The apparatus is particularly useful in a magnetic recording and reproducing system for digital video data signals. The apparatus effectively stores the digital video data that occurred 262 video lines prior to the current data at the input and continuously updates, (i.e., stores in place of) the stored data with current data unless defects occur in the current data, in which case the defective current data is not stored. The data from the store is inserted in the video data streams when the drop-outs or parity information associated with the data stream indicates that the current data is defective.

Abstract: Apparatus is disclosed for providing error compensation for a digital video information signal and is particularly adapted for use with a PAL format video information signal. The apparatus takes advantage of sampling being done in a precise manner, i.e., at a rate of four times the chrominance subcarrier frequency of the PAL information signal, and alternately along the U and V vector axes. The apparatus generates a substitute value for a defective sample that is the average of selected samples which are in close proximity to and which are of the same type as the defective sample. More particularly, replacement samples taken along the U vector axis (U samples) are generated by averaging the nearest in proximity U samples and the replacement V samples are obtained by averaging the nearest in proximity V samples. Switching means appropriately substitute the generated values for the defective values so that V samples replace V defective samples and U samples replace defective U samples.

Abstract: Trim signals are removed from the fuel control computers of aircraft propulsion engines to increase thrust upon detection of a predetermined difference between engine speeds.

Abstract: Minimal realization of an optimum amplitude and phase equalizer is disclosed. A first amplifier circuit including first respective passive filter elements provides both high and low frequency amplitude equalization. A second amplifier circuit including second respective passive filter elements provides first, second or higher order phase equalization, respectively, with gain. The equalizer operates between voltage sources and virtual ground to minimize noise picked up from parasitic capacities and external sources.

Abstract: A deflection coil driver includes a current driver stage comprising three power transistors, a first power transistor being caused to turn on via a class B transistor stage when an input signal of a first polarity is input to the class B stage, second and third power transistors being caused to turn on via said class B stage when the input signal has an opposite polarity. When turned on, the first power transistor couples current from a positive voltage source to the deflection coil, the second power transistor couples current from a negative voltage source to said coil, and the third power transistor couples said coil to ground. A transistor switch determines whether the second or the third power transistor is on, as a function of the voltage across the deflection coil. The current through the coil is also sensed and provides negative feedback to an input amplifier to ensure that the shape of such current matches the shape of the input signal.

Abstract: A low cost, low power inhibit current drive circuit includes a pair of sense-inhibit conductors each inductively coupling 16K low drive memory cores and having sufficiently low resistance to permit steady state inhibit current magnitudes to be energized by a 5 volt source which is diode coupled thereto, a switch coupled to selectively pass inhibit current in response to a command signal, a storage capacitor coupled to the transistor collector, and a series combination of an inductor and a resistor coupled to charge the capacitor to a voltage greater than 5 volts and thus provide a rapid rise of inhibit current to the steady state level upon closure of the switch. Use of the charged capacitor to provide high voltage energy at switch closure reduces the required maximum current from the high voltage source while the inductor reduces capacitor charging time for a given size of series resistor to further reduce the maximum current requirement from the high voltage source.

Abstract: An input video processor utilizes the characteristics of a modulator having two differential pairs of transistors with respective gain control terminals, in combination with a switch. The processor performs four distinct functions utilizing the same basic modulator; it provides blanking the video signal from the preamplifier to provide a clean pulse for clamping at a later stage; it clamps the output during black level firmly to ground potential to allow subsequent blanking; it allows the manipulation of the master gain of the three channels in a color television while independently adjusting the gain of the channels, while further maintaining absolute tracking between channels; and it provides an independent gain control input for a white shading control voltage input to perform white shading corrections.

Abstract: A simplified automatic error correction setup system is coupled to the remote control multiplex/demultiplex circuitry in a color camera to generate and store respective error correction control voltages for selected operating parameters during a camera setup mode, with subsequent automatic retrieval of the stored error correction control voltages during camera operation. The automatic control voltages are digitally generated from incoming error signals via a control system loop generally formed of an error selector switch, a digital register, a digital-to-analog converter (DAC) and a random access memory (RAM). The register and/or RAM data are converted to analog control voltages via the DAC for each parameter (i.e., channel) being automatically corrected, which voltages are linearly summed with the corresponding control voltages. During the automatic setup mode, the RAM contents are updated via the register for any existing errors in the specific operating parameters.

Abstract: Highly orientable acicular iron particles are made by reducing an acicular ferric oxide which has been coated with sodium tripolyphosphate.

Abstract: Precise, point-by-point correction of spatial and shading errors in a camera television picture are performed manually. The errors to be corrected are determined by visually examining a picture on a video monitor, by selecting an area for error correction which area corresponds to the type and extent of the specific error selected for correction. A position command increments or decrements an address by preselected steps to locate a movable "cursor" which, in turn, identifies the area being corrected. A correction command retrieves the data from the area identified, and which contains the error, selectively increments or decrements the data in preselected steps, and stores the new data back in memory. The process continues until the operator is satisfied with the correction results. Correction thus may be made point-by-point, along horizontal or vertical lines or areas, in selected corner areas, etc., of the picture.