Abstract: A switching arrangement for activating a plurality of electrical devices connected to a communication line. The switching arrangement monitors the communication line for the reception of activation signals, and also transmits activation signals to the communication line. The switching arrangement activates an electrical device (from the plurality of electrical devices) connected to the communication line, in response to the detection of the an activation signal, to shift the electrical device from a dormant state (in which electrical consumption by the electrical device is minimized) to a normal, functional operational state (in which a maximum electrical consumption of the electrical device occurs) only when the electrical device is actually being operated. By switching the electrical device between a dormant state and an operational state, the amount of electrical power required to operate the plurality of electrical devices is reduced.

Abstract: A method for correction errors in radar systems that operate using a crossfeed principle (CFR), in which echo signals are directly received from flying objects, such as an aircraft. In particular, the present invention is used in connection with low-flying objects, in which radar signals are indirectly reflected from the surface of the earth to an antenna of the radar system. Correction terms are determined and weighted, using correction factors, so as to improve the capability of the crossfeed radar system to accurately determine the exact elevation of the flying object. The correction factors that are used to improve the accuracy of the radar system are based upon sea state numbers, or Beaufort numbers, which vary in relation to the shape and/or structure of the reflecting surface.

Abstract: A method and apparatus for conducting a conference call among a plurality of subscriber stations. Each subscriber station contains a transmitter, a receiver, and an auxiliary receiver. An output of the auxiliary receiver can be selectively connected to an adding member that is located between a microphone and an input of the transmitter. The subscriber stations establishing the conference call connection form a transmission chain. Each subscriber station involved in the conference call, with the exception of the first subscriber station on the transmission chain, receive a user signal of a preceding subscriber station. The user signal of the preceding subscriber station is added to its own user signal to produce a compound signal that is transmitted to the next subscriber station on the transmission chain. A compound signal created in the last subscriber station of the transmission chain is supplied to the receiver of all the subscriber stations on the transmission chain.

Abstract: A radar system, such as a tracking radar installation or other radar installation which is of the pulse compression type, transmits data during transmission of the radar signal. The data is transmitted by inserting, into the radar signal, at least one short nonpulse interval. The position of the nonpulse interval within the radar pulse can be modulated.

Abstract: An attenuation network comprises a T or a .pi. network and first and second regulating circuits for controlling it. The T or .pi. network has at least two variable resistances. A switch S1 permits selection of a desired attenuation value which is set through the operation of the second regulating circuit on the T or .pi. network, while the first regulating circuit acts on the T or .pi. network such that its input and output resistances are kept constant.

Abstract: A frequency synthesizing device generates periodic electrical oscillations of a frequency that can be arbitrarily determined, in which, after changing the frequency and resetting it to any desired value that has previously been generated, phase coherence is maintained. In addition to the elements of a direct digital frequency synthesizing device, the arrangement according to the invention has a time measuring unit (ZME) and a control logic (SL). The time measuring unit (ZME) periodically counts through a time interval from t=0 to t=t.sub.z and transmits the count status or a time signal to the computing system (R). The frequencies f.sub.i to be emitted and the time interval from t=0 to t=t.sub.z are chosen in such a manner that the phases of all the frequencies f.sub.i take on a constant value at the time t=0. This makes it possible to compute the coherent starting phase .phi..sub.N, so that the new frequency f.sub.N can be generated, with phase coherence, as of the time t.sub.

Abstract: A frequency synthesizing device comprises two reference frequency generators RG1 and RG2, an offset stage OS and a phase-locked loop PLL. In the phase-locked loop, which operates as a tracking filter, the output frequency fs.sub.A is generated by the addition of the frequencies f.sub.RG1 and f.sub.OS. The output frequency fs.sub.A has a very high spectral purity, since all interfering spurious signals are blocked by the tracking filter. By a proper selection of the reference frequencies f.sub.RG1, f.sub.RG2 and f.sub.OR, it is ensured that all interfering spurious signals lie outside the bandwidth B.sub.TF of the tracking filter and are accordingly blocked. As a result, it is not necessary to filter the signals S.sub.RG1, S.sub.RG2 and S.sub.OS.

Abstract: A radar system operating by the line-of-sight method requires an accurate measurement of the relative position of at least two objects. By sending out coded radar transmission pulses, control data are transmitted to a guided flying body in a radar beam, which sends back an echo signal to the receiver via a transponder. In order to measure the passive signal and the transponder echo signal in the radar beam as accurately as possible, common reception channels are provided for both echo signals containing, inter alia, arrangements to equalize the dynamic levels of the echo signals. The returned transponder echo signal corresponds with respect to coding and bandwidth to the transmission pulses originally generated in the transmitter and that are phase-coded but not provided with the control code.

Abstract: In a radar system, comprising a digital expander, two analog modulation signals are generated with two digital to analog converters and raised to an intermediate frequency range through a quadrature modulator. The amplitude and phase ripple of the output signal occurring in the quadrature modulator due to limited carrier and image frequency suppression are compensated through a multiple regulating circuit. To this end, if necessary calibration signals, of constant amplitude and different phase positions, are generated sequentially by means of the two digital to analog converters and the amplitude of their output signals measured in an amplitude detector. Setting values for the multiple regulating circuit are determined from the averaged amplitude measured values in a phase and amplitude correction unit which via setting elements set the requisite offset and phase and amplitude symmetry values until the deviations of the output signal in amplitude and phase disappear.

Abstract: Radar systems that operate in accordance with the crossfeed method require an exact balancing of the individual Doppler frequency evaluation channels in the receiver. According to the invention, a special method is used first to make the amplitude levels in the individual channels equal to one another and then to determine and balance the phase differences between the channels. A radar system using this method is also described.

Abstract: An expander system for pulse signals with enhanced output power level is disclosed. The expander system, which comprises an expander filter and subsequently connected amplifier means, is provided with a supplementary 180 degree phase modulator connected in front of the expander filter. The phase modulator is switched on and off by a control signal delivered from a control stage in such a manner that, during the duration of a pulse signal, the phase modulator produces at least two phase shifts of approximately 180 degrees.

Abstract: An expander system for pulse signals with enhanced output power level is disclosed. The expander system, which comprises an expander filter and subsequently connected amplifier means, is provided with a supplementary 180 degree phase modulator connected in front of the expander filter. The phase modulator is switched on and off by a control signal delivered from a control stage in such a manner that, during the duration of a pulse signal, the phase modulator produces at least two phase shifts of approximately 180 degrees.

Abstract: A housing suitable for an electrical or electronic component such as a relay, including a wall having apertures (5, 6) and gaps (7) wherein distribution ribs running on the outside form with the housing surface a sharp inner edge (10). Due to these sharp inner edges, capillary action of the sealing compound is developed on the distribution ribs whereby the sealing compound is transported from a dispensing site to the apertures (5, 6) and housing gaps (7).

Abstract: An operation support system architecture for a telecommunication system contains a control arrangement (BWS) inserted between the system (S) to be operated and an opertor station (DSS). The control arrangmeent comprises, besides a processor and an input/output unit (EAB), a memory (RSP) which contains the operating and maintenance knowledge of the system (S), namely in the form of the CCITT Specification Language SDL/PR. Further the control arrangement (BWS) comprises a correlation memory (ZSP) in which are stored the definition for the formation of MML commands to the system (S) and the formal description of the reactions expected by the system (S). On the basis of the data in the two memories (RSP, ZSP), a translator (I), also present in the control arrangmeent (BWS), can send the correct and properly structured commands directly to the system (S) or respectively evaluate the reactions of the system (S).

Abstract: The controlled switching array comprises four commutator components and four associated signal distributors. Each signal distributor has an input side to which an input signal is applied which, in turn, is fed to a respective input on the input sides of the commutator components. The commutator components are symmetrically arranged on both sides of a printed circuit board. There thus results a favorable decoupling of signal lines from each other as well as from the output side.

Abstract: During the pre-soldering or tinning of printed circuit boards, as a rule, also the drill holes or bores and, in particular, the through-metallized drill holes are filled in an undesirable manner with solder. This solder must be removed before mounting the electrical components or elements upon the printed circuit boards. A simple apparatus is disclosed for this purpose, affording a faultless de-soldering of the drill holes, without deleteriously affecting the properties of the solder material. The printed circuit boards, in a condition where the solder applied during the pre-soldering operation is still molten, are accelerated at least once and thereafter suddenly brought to standstill in such a fashion that the excess solder is knocked or propelled out of the drill holes.

Abstract: A type of transmitter, that transmits an unexpanded continuous unmodulated signal following a predetermined number of transmission pulses, is disclosed for the regulation of a multichannel pulse compression system. At least two compression channels are available which are inserted between a microwave receiver stage and a demodulator. A respective monitoring signal is extracted from the output of each compression channel and these monitoring signals are compared in a control circuit in order to obtain a phase difference signal and an amplitude difference signal. A respective control signal is derived from each difference signal in order to regulate a phase shifter and an attenuation circuit, which are provided in at least one of the compression channels, in such a manner that the phase difference signal and the amplitude difference signal are compensated towards zero.

Abstract: In order to compensate the unwanted echo caused by the movement of a moving radar device, an arrangement is provided between the output of a coherent oscillator and the input of a phase discriminator. This arrangement comprises a signal processing stage containing two series-connected phase regulating circuits, namely phase-locked loops. The output signal of the first phase-locked loop displays a mixed frequency which is formed by the sum of the frequency of the output signal of a signal generator and a displacement frequency modulated by the Doppler frequency of the unwanted echo caused by the movement of the radar device. In the second phase-locked loop the output signal of the first phase-locked loop is mixed with a further signal containing the displacement frequency.

Abstract: A surface acoustic wave (SAW) filter features a ground lead in a transducer that has an aperiodic meander structure. This arrangement permits the self-capacitance and inherent resistance of the transducer to be utilized in forming the RC networks of a phase shifter associated with the transponder.

Abstract: An oscillating device has an electro-mechanical drive, a pivotal or oscillating armature and a regulating circuit, wherein a capacitor, the capacitance of which varies with oscillation of the armature is used as a displacement transducer or pickup. A signal generated by a signal generator is conducted by way of the series-connection of the displacement transducer, a rectifier and a filter to an amplifier circuit, the frequency of said signal being much greater than the natural resonant frequency of oscillation of the electro-mechanical drive. An output voltage which is substantially in phase with the angular movements of the armature i.e. angle-proportional thereto, appears at the output of the amplifier circuit and is supplied to a set value input of a differential amplifier contained in the regulating circuit.