Abstract: For generating an RF signal modulated by a message and distorted by a predetermined fading profile for testing RF receivers, a sequence of digital phase and amplitude values which corresponds to the message modulation is arithmetically processed by a predetermined fading profile and stored in memory, and an RF carrier is amplitude and phase modulated by the stored values to produce a testing signal for the RF receivers.

Abstract: In an apparatus for automatic component insertion in p.c. boards by means of an industrial robot, the gaging means for optically gaging the components is disposed on the outer robot arm so as to be directly associated with the range of motion of the component gripped by the robot.

Abstract: For determining the transmission function of a video camera, a bar pattern is taken in which the width of the bars is selected to be sufficiently small so that their influence on the amplitude and phase response of the electric pulse that is produced upon scanning of a bar in the camera is negligible; the narrow electric pulses thus produced at the output of the video camera are selected and subjected to Discrete Fourier Transformation.

Abstract: A sine-wave oscillator produces a sine-wave signal of a digitally predetermined frequency f in successive steps by only one multiplication and one addition under control by a clock generator having a clock frequency p. During a first step the value A.sub.(i+l) =A.sub.i +B.sub.i .multidot.k is determined and during a subsequent second step the value B.sub.(i+l) =B.sub.i -A.sub.(i+l) .multidot.k is determined therefrom, A.sub.(i+l) and B.sub.(i+l) being the respective newly calculated values, A.sub.i and B.sub.i being the respective previous values calculated in a preceding step, and k being a factor k=2.multidot.sin (.pi..multidot.f/p) calculated in a computer. The period of the successive steps is selected to be 1/2 p, and for the first step A.sub.(o) =0 and B.sub.(o) =cos (.pi..multidot.f/p) are selected. At least one of the two factors A.sub.(i+l) and B.sub.(i+l) is finally converted to an analog sine-wave signal in a digital-to-analog converter.

Abstract: For recombining a message transmitted by a frequency hopping transmitter at a fast changing transmitting frequency, there are used a digital FFT search receiver for cyclically evaluating the frequency band occupied by the frequency hopping transmitter, at least one interception receiver capable of being switched by the FFT search receiver to the respective instantaneously used transmitting frequency of the frequency hopping transmitter, and a digital storage in which the stream of digital output data from the output of the permanently operative analog-to-digital converter of the FFT search receiver is temporarily stored, the delayed stream of output data from the storage being supplied to the input of the interception receiver.

Abstract: A network for compensating the non-linearity of an amplifier has an auxiliary network provided either before or behind said amplifier.

Abstract: For the synchronized display of MAC signals on a monitor designed to display standard video signals, a decoding device derives synchronizing pulses from the data component of the MAC signal which contains the line-frequency and field-frequency information, and a blanking stage is triggered by the synchronizing pulses for the periodic blanking of a partial segment of the MAC signal to a predetermined constant voltage level in a standard-suitable temporal relationship to the synchronizing pulses.

Abstract: In a power sensor for RF power measurments, comprising a thin-film absorbing resistor formed on the top surface of a support member and a thermocouple which is electrically isolated from the circuit of said absorbing resistor, the absorbing resistor is formed on an insulating film of a silicon support member so as to increase the sensitivity and to facilitate manufacture thereof, the silicon support member including an island formed beneath the absorbing resistor, a thermally conducting portion formed in spaced relationship thereto with a narrow bridge portion provided inbetween, and said thermocouple being constituted by the bridge portion and by mutually spaced contact zones formed thereon.

Abstract: A logic analyzer has a plurality of data channels and clock channels which are connectible to a digital circuit. Each clock channel has associated therewith a temporary memory connected to all of the data channels, and the data stored in the temporary memories are successively delivered to a data memory under the control of master clock signals.

Abstract: For a fast and accurate frequency response compensation of a spectrum analyzer, the frequency-dependent control values for controlled amplifier are stored as digital values in a digital memory, and in between the memory and a sweep generator of a heterodyne oscillator, an analog-to-digital converter is disposed to provide frequency-proportional digital values of which the associated frequency-dependent control values stored in a memory can be selected and supplied to the controlled amplifier.

Abstract: An arrangement is provided for enhancing the accuracy of frequency determination in a spectrum analyzer or the like having a local oscillator heterodyned with and locked to a frequency comb, by providing a determination of whether the local oscillator frequency is above or below the comb frequency to which it is locked, thereby avoiding ambiguity in the determination of the local oscillator frequency.

Abstract: A system for the automatic establishment of a shortwave telegraphy signal connection between two transmitter-receiver stations within a frequency range subdivided into several channels. Both stations use their receiver to determine objective measurement values reflecting the transmission conditions over the individual channels. Active and passive channel analysis of the actual quality of the signal transmission is determined at each channel. The transmitter of the calling station is automatically tuned to the channel which corresponds to the best channel quality stored in its memory. A predetermined time after transmitting the call signal, the calling station switches to reception and upon reception of an acknowledgment signal from the counter station automatically begins the message transmitting-and-receiving operation. If after a predetermined time no acknowledgment signal is received, the transmitter automatically switches to the channel stored in its memory with the next best channel quality value.

Abstract: In order to automatically set a predetermined frequency component of a voltage-controlled oscillator of a spectrum analyzer which is swept by a sweep voltage to a prescribed point of a frequency coordinate on a display device, the oscillator is connected into a phase control loop of a frequency synthesizer as its oscillator. This connection is by way of one switch position of a transfer switch, in which the tuning voltage supplied by a phase comparator of the control loop is supplied to a storage element and, in the other switch position, the phase control loop is opened and the output of the network connected to the storage element is connected to the control input of the oscillator. The network is controllable by way of a control voltage such that the stored tuning voltage may be supplied to the control input of the oscillator as a reference voltage for the sweep voltage.

Abstract: An antenna matching apparatus tunable to different frequencies is disclosed for use with a high frequency transmitter that is rapidly switchable between different transmitting frequencies by a control unit according to a predetermined frequency scheme. This apparatus which is tunable as quickly as the transmitter, includes two or more antenna tuning means tuned to different frequencies which are tuned to different frequencies and switched rapidly by the control unit.

Abstract: A phase-controlled high frequency oscillator has a phase comparator for comparing the oscillator frequency to a reference frequency which comparator controls two direct current sources connected to a charging capacitor for supplying charge pulses to the charging capacitor which in turn generates a charge voltage which determines the frequency of the oscillator, which is voltage controlled. The control of the current sources is undertaken in such a manner that in the steady-state condition of the phase control loop, both current sources supply relatively short charge pulses of equal size and opposite polarity to the charging capacitor. An auxiliary circuit generates a correction current proportional to the integral of the difference between the charge pulses supplied by the two current sources and is connected to the charging capacitor for further controlling the voltage controlled oscillator. The auxiliary circuit is designed such that only relatively short charge pulses generate a correction current.

Abstract: A radio direction finder for obtaining the bearing of a transmitter with respect to a receiver comprises a multi-element receiving antenna, two separate scanning means coupled to said antenna for simultaneously generating a rightward and a leftward rotating antenna pattern of the same rotating frequency, and two separate receivers having approximately the same group delay. Also included are demodulating means for generating two separate bearing signals of AM or FM-type modulation for the rightward and leftward rotating antenna pattern, respectively, and evaluator and indicator means for obtaining the bearing of a signal received by the antenna from the phases of the two bearing signals and a reference signal. As a result, the radio direction finder provided, being of the most simple structure, permits quick evaluation of the bearing, for instance, during one revolution only of the antenna characteristic, and yet includes no bearing errors caused by delay.

Abstract: A device for inspecting an individual high frequency signal selected according to frequency from a broad frequency band comprises a voltage controlled oscillator which can be controlled with respect to frequency by a periodic sweep voltage, in particular a linear sawtooth voltage, in such a manner that all signals occurring in the frequency band can be displayed as a spectrum in the picture screen of a cathode ray tube. The device further comprises a frequency marker generator which has a device for generating a frequency mark voltage and a voltage comparator for, given sweep operation and equality between an adjusted frequency marker voltage and a momentary sweep voltage, generating a frequency mark on the picture screen which is adjustable to identify a corresponding fixed frequency after termination of the sweep operation for inspecting an individual frequency-selected signal.

Abstract: In a sound level meter the output voltage of the microphone is fed to a voltage-frequency converter by way of an exponentially operating circuit, such as a squarer, and the output of the converter operates a binary counter having an indicator unit associated therewith. A gate circuit is controlled by a timing generator and is interposed between the voltage-frequency converter and the binary counter. The indicator unit includes a plurality of indicating elements which are connected at the outputs of the successive counter stages and each of the indicator elements is associated with a particular indicia carried on a dB scale. With a squarer as the exponential circuit the dB scale has a 3 dB incrementation for the respective indicator elements.

Abstract: An automatic direction finding system for an airplane which utilizes ground equipment for automatically determining the line of position of aircraft transmitting radiant energy and which calculates the aircraft's line of position and transmits such line of position to the aircraft over an available audio channel. The ground station may be unmanned and provides for storage means for converting the aircraft's bearing from the station into an audible message which can be automatically transmitted to the aircraft.