Abstract: A deflection device for the electron beam, in, for example, an image pick-up tube, comprising an annular yoke of a magnetic material, having at least two pairs of diametrically arranged, inwards directed cores which are enveloped by deflection coils. On the inner end of each core there is provided a poleshoe in the form of a ring segment, said poleshoes enclosing a deflection space. In order to ensure that the shape of the generated deflection fields can be accurately and reproducibly defined, each coil is situated, viewed from the deflection space, completely behind the associated poleshoe, the spaces between the poleshoes being bridged by intermediate pieces of a non-magnetic material.

Abstract: An amplifier arrangement with a class-B output stage comprising two complementary current mirrors whose output circuits are included in series between supply terminals. The input circuits of these current mirrors are driven by output circuits of a third and a fourth current mirror, which current mirrors each couple the drain electrodes of two transistors which respectively constitute a first and a second differential amplifier with common input terminals.

Abstract: A device for the acquisition and storage of an electrical signal.The signal is divided into adjoining elementary time intervals of specific duration. During each of them the amplitude minimum and amplitude maximum of the signal are established, which values are first stored in analog form and subsequently in digital form.The device may be utilized in oscilloscopes, in particular those of the type comprising a matrix display panel.

Abstract: A line sawtooth deflection current generator with modulating means for the purpose of correcting the amplitude variations of the current produced, the said modulating means including a stage operating in the switching mode.

Abstract: Electric network for use in a subscriber's loop, comprising at least two connecting terminals for supplying thereto a current flowing in the subscriber's loop, the network comprising the series arrangement of a capacitive element and a switching device and a threshold device coupled to the connecting terminals and the switching device for either coupling or not coupling, depending on the polarity and the value of said current, said capacitive element to the terminals of the network. This results in a network whose pattern of behavior is optimum for the various signals which are exchanged in the loop.

Abstract: A sawtooth generator for producing a sawtooth voltage of constant amplitude, comprising a transistor having, in the emitter lead, a resistor in series with a capacitor, a switch being in parallel with this capacitor. A second capacitor is included between the base and the junction point of the resistor and said first capacitor. A high-value resistor is connected between a d.c. voltage source and the base. The generator can also be made self-oscillating.

Abstract: A multiplex system has an inverse Fourier transformer that is unequal to its forward one, therefore an optimum distribution of elements is possible.

Abstract: A data receiver with synchronizing-sequence detection circuit which comprises a bandpass filter for selecting a channel signal component of carrier frequency f.sub.c, a zero-crossing detector, pulse interval measuring means and a pulse pattern analyzer, which detection circuit detects on the basis of the substantially constant period duration of f.sub.c the synchronizing period associated with the synchronizing sequence of which detects on the basis of the no longer constant period duration of f.sub.c the training period following after the synchronizing period.

Abstract: A digital filter and demodulation arrangement for passband signals, whose corresponding baseband signal has a bandwidth limited to a given maximum frequency. The passband signals are filtered according to two bandpass characteristics which, apart from their asymmetrical distortion relative to their central frequency, are versions from one another shifted 90.degree. in phase. The filtered passband signals are demodulated with an in-phase carrier and a quadrature carrier and the demodulated signals are combined to a baseband signal.In the digital filtering process the sampling frequency is reduced from a value higher than twice the highest frequency in the passband signals to a value which is not higher than twice said maximum frequency in the baseband signal and in the digital demodulation and combination processes the reduced sampling frequency is also used so that a considerable reduction in the internal processing speed is obtained.

Abstract: A circuit for detecting changes in the amplitude of a video signal features a sampler for sampling the signal. The sampled signal is then held and delayed by a selected amount. The delayed and undelayed signals are then compared and when the difference exceeds a threshold, an output signal is supplied.

Abstract: A line sawtooth deflection current generator with modulating means for the purpose of correcting the amplitude variations of the current produced, the said modulating means including a stage operating in the switching mode, a switch of which is connected via a smoothing inductance. A winding coupled to an inductance in the deflection circuit is provided in the branch of the smoothing inductance between the scan capacitor and the switch.

Abstract: Phase-locked loop having a controllable oscillator and a phase detector for generating an output signal which is applied as control signal to the oscillator through a loop filter comprising a storage element, which loop filter is switchable under the control of a control circuit between a first state wherein the loop filter has a wide passband and a second state wherein the loop filter has a narrow passband, provided with an arrangement connected to said storage element for determining the instants at which the instantaneous value of the signal stored in the storage element is equal to the average value of the control signal for the oscillator, the control circuit being arranged such that, after locking, switching-over of the loop filter from the first to the second state is done at one of the instants determined by said arrangement.

Abstract: An arrangement for simultaneous two-way data transmission of data signals with a given symbol frequency over two-wire circuits of a type found in telephone networks or of a comparable type. The arrangement comprises an echo canceler with an adaptive filter for producing from transmit channel signals approximated echo signals which are differentially combined with receive channel signals for forming substantially echo-free residual signals. A special type of code conversion is employed in the transmit channel, whereby p-level data symbols are converted into modified p-level data symbols which are thereafter converted into (2p-1)-level data symbols. The echo canceler comprises a digital adaptive filter to which the modified p-level data symbols and the residual signals with a sampling frequency equal to the symbol frequency are supplied.

Abstract: A method for aligning a deflection unit on an in line CRT uses a multipole field generated by the deflection unit. The center beam is turned on and the deflection unit aligned until it makes a single dot pattern on the CRT screen.

Abstract: A system for recording a color television signal. The color information is recorded as an amplitude modulation. This color information consists of a first and a second color-difference signal, which two color-difference signals are transmitted in a line-sequentially alternating exhibiting a 90.degree. phase-shift during consecutive line periods. Third and fourth additional signals are quadrature-modulated with the first and second signals, respectively. Each of these additional signals comprises the difference between one of the color-difference signals during a selected line period and the value of the same signal during the preceding or next line period.

Abstract: A black-white or color television camera comprising a pick-up tube, provided with a signal electrode composed of separated strips. Prior to a line scan to be performed by an electron beam, the signal electrode strips are connected to a reference potential. After a scan the strips are through-connected successively through associated switches for supplying information. The switch outputs are alternatingly, in at least two groups through-connected and connected to at least two output leads. Always two stitches, which are connected to two adjacent strips are closed simultaneously. In this way it is avoided that a capacitive voltage distribution across the strips and switch inputs influence the picture signal obtained in a disturbing manner.

Abstract: A television player adds an identification signal to the recorded video signal so that a receiver with a recognition circuit can distinguish between the played back signal and a broadcast one. The identification signal is compatible so that a receiver without the recognition circuit can receive the played back signal.

Abstract: In a delta-modulation encoding arrangement having step-size control drift voltages and miss-match between the charge and discharge pulses for the first integrating network in the feedback circuit produce an additional DC voltage on this integrating network. This additional DC voltage is compensated by an additional feedback circuit comprising a second integrating network. However, if the signal to be encoded rapidly decreases from a large to a small amplitude and when after this rapid decrease the information signal only has a small amplitude an additional distortion is introduced for these small signals. To obviate this a modulation arrangement is included in the extra feedback circuit, which modulation arrangement is controlled by a control signal which derives a control signal from the delta modulation output pulses.

Abstract: By using a double potentiometer one of which is used for tuning and the other for adjusting a level whose variation suppresses an automatic tuning correction, a great freedom can be obtained in designing the tuning section of a receiver with automatic tuning correction suppression.

Abstract: An in-line CRT features a static convergence means. It has at most two permanent magnets in or around the tube neck before the deflection coils.