Abstract: The anode cavity of a power magnetron is connected through a coupling slot to a reactively terminated waveguide structure containing one or more selectively magnetizable ferrite elements acting as adjustable differential phase shifters for two microwave components circulating in opposite directions through the structure or traversing a guide portion in the same direction but with opposite circular polarization. In the first instance the structure comprises two parallel rectangular-section waveguides with a common lateral wall having a proximal and a remote opening serving as directional couplers therebetween; in the second instance the structure is a circular-section waveguide with a main portion occupied by the ferrite element and transition portions separating that main portion from the coupling aperture and from the reactive termination.

Abstract: A carrier oscillation in the microwave range is stabilized by a sequence of timing pulses produced by a crystal-controlled reference oscillator whose cadence is an aliquot fraction of the nominal carrier frequency. The pulses are used to obtain two phase-representing amplitude samples of the carrier wave from a pair of mutually phase-shifted pilot oscillations of the same frequency in each of a succession of nonconsecutive cycles thereof; a control voltage derived from these amplitude samples is fed back to the microwave oscillator via a frequency-correcting or phase-locking loop.

Abstract: To test the performance of an analog/digital converter, used for translating bipolar message signals into 8-bit words, the analog input of the converter is connected across a voltmeter while its digital output works into a buffer register distributing the seven amplitude bits of an emitted code word to one set of stage inputs of a comparator having another set of stage inputs connected to a manually operable word simulator; the sign bit of the code word is entered in a separate store. A logic network with inputs connected to the sign-bit store, the comparator and the word simulator controls two reversible counters which, upon manual operation of the word simulator, emit selected numerical values translated by associated digital/analog converters into output signals fed to the analog/digital converter to be tested.

Abstract: Two variable-frequency microwave generators, i.e. a coaxial magnetron producing outgoing waves and a voltage-controlled oscillator emitting a heterodyning signal for incoming waves of a radar transceiver, are continuously tuned by a pilot signal modifying their operating frequencies with a predetermined constant separation. To maintain this correlation, the tuning circuit of at least one microwave generator responds to the pilot signal through the intermediary of a read-only memory which, on being directly or indirectly addressed by that signal, emits stored setting instructions for the respective generator.

Abstract: An interface unit inserted between a subscriber line of a telecommunication system and a generator of dial pulses, including a signal converter associated with a pushbutton selector and a memory for the temporary storage of selected digits, comprises a rectifier bridge in series with an impedance network which includes a shunt branch with two complementary transistors interconnected in a positive-feedback circuit and a low-threshold Zener diode in series with one of these transistors across which a reduced supply voltage for the pulse generator remains available when the shunt branch becomes conductive with saturation of the transistors upon a closure of the subscriber's hook switch. An enabling signal for the pulse generator is emitted from the shunt branch upon such conduction. An ancillary transistor, with an input connection across a small series resistor of the network, and a further Zener diode in parallel with the shunt path protect the components thereof against overcurrents and overvoltages.

Abstract: A prismatic frame designed to hold a multiplicity of flat articles such as printed-circuit boards has two generally rectangular end walls interconnected by two coplanar pairs of cross-members each having a narrow face with a row of perforations receiving locator pins of guide elements spanning each pair of cross-members, the guide elements being provided with longitudinal channels accommodating respective boards. The guide elements are held in position by retaining bars confronting the perforated faces of one cross-member of each pair, at least one of these bars forming a guidetrack for a locking rod which has teeth alignable with the boards in a blocking position and is shiftable into an unblocking position facilitating their withdrawal.

Abstract: A frequency discriminator designed to respond to a selected incoming tone frequency comprises a pulse generator connected via an adjustable frequency divider to a binary 8-stage counter which generates eight relatively staggered pulse trains whose cadence varies with the setting of the divider. This setting can be varied, e.g. in a programmed manner according to a pattern of tone frequencies to be recognized, while incoming signals are applied to an eight-path filter driven by the staggered pulse trains. When the cadence of the pulse trains matches an incoming tone frequency, the filter emits an output exceeding a predetermined threshold.

Abstract: A receiving station of a data-transmission system decodes an incoming pulse train in the shape of a differentially biphase-coded carrier wave whose cycles represent rspective message bits; the wave undergoes a phase reversal at the beginning of every cycle in which the transmitted binary signal has the logical value "1" but does not change in phase when that value is "0". The received pulse train is differentiated to yield either one or two spikes during each cycle, one such spike invariably occurring in the middle of a cycle. Since only these periodically recurring spikes determine the instants at which the carrier wave must be sampled during decoding, a gate in the differentiator output is blocked during part of each cycle by a locally generated square wave which also controls the sampling.

Abstract: A load, such as a logic network of the TTL type, is connected in parallel across a plurality of direct-current sources designed to maintain a substantially constant operating voltage. Each source includes a control unit which compares the load voltage with a reference level in order to stabilize the output voltage of an associated current generator at that level. If the generator current drops below a certain minimum value, however, a threshold sensor in the control unit raises the reference level up to an amount equaling about twice the maximum divergence possible between the reference levels of different control units, thereby ensuring that all sources contribute simultaneously to the load current.

Abstract: Data pertaining to the operation of a signal-processing system are written in zones of a central read/write memory which are either permanently or temporarily allocated to respective peripheral units to be monitored and which are each divided into a plurality of phases accommodating multibit words. An interface unit, designed to read out the contents of one or more phases of a memory zone allocated to a chosen peripheral unit and to transfer them to a kinescope or a printer for visualization, includes a buffer store connected to the memory and controlled by a command circuit which responds to several selectors receiving the output signals of an address counter identifying the several memory zones and phases. In the case of temporary allocation, each peripheral unit has a three-word code entered in predetermined phases of the allocated zone which can thus be identified by one of the selectors of the interface unit.

Abstract: A resonant cavity of a microwave generator, such as a magnetron oscillator, is provided with a tuning piston which is rectilinearly displaceable between two terminal positions, corresponding to respective limiting frequencies, by means of a rotating crankshaft whose eccentric portion constitutes the inner race of a ball or roller bearing. The outer race of that bearing rolls, directly or through the intermediary of a captive spherical or cylindrical coupling member, on a transverse face of the tuning piston held in contact therewith by spring pressure.

Abstract: A synchronous demultiplexer at a receiving station of a TDM/PCM telecommunication system, operating on an incoming bit stream organized in frames of 32 time slots of eight bits each, comprises a random-access memory having 32 cells loaded with consecutive octets in successive time slots under the control of a writing-address generator, stepped by clock pulses extracted from the bit stream, and unloaded at a similar but not exactly identical rate under the control of a reading-address generator, stepped by locally generated clock pulses. Two series of loading pulses a and b, each lasting for a bit period t, are derived from the extracted clock pulses near the beginning and near the end, respectively, of a time slot of duration T'=8t and are fed to a control unit together with a series of unloading pulses c of length 2t occurring once per cycle T".apprxeq.T' measured by the local clock.

Abstract: In order to determine the maximum level of a coded signal from a selected communication channel appearing in the output of a PCM multiplexer in which bit groups from several such channels are interleaved in a time-division mode, PCM bytes arriving in time slots assigned to the selected channel are fed to a comparator which causes their entry in a primary register if their numerical value exceeds that of a previous entry. After a predetermined number of PCM frames, e.g. 64, a peak-level byte represented by the contents of that primary register is transferred to a first secondary register whereupon the same procedure is repeated two more times with storage of additional peak-level bytes in two other secondary registers. In a fourth operating phase the contents of the three secondary registers are compared and, if identity is established between at least two of the bytes stored there, such a stored byte is delivered to a decoder controlling an oscilloscope to display the detected signal level.

Abstract: A synchronous demultiplexer at a receiving station of a TDM/PCM telecommunication system, operating on an incoming bit stream organized in frames of 32 time slots of eight bits each, comprises a pair of substantially identical random-access memories each having 32 cells loaded with consecutive octets in successive time slots of a frame period P' under the control of a writing-address generator, stepped by clock pulses CK' extracted from the bit stream, and unloaded at a similar but not exactly identical rate in successive time slots of a period P" under the control of a reading-address generator, stepped by locally generated clock pulses CK". Writing as well as reading addresses are fed to both memories simultaneously but the two memories are loaded in alternate frame periods P' and unloaded in alternate frame periods P" under the control of selection signals in the form of two square waves respectively derived from clock pulses CK' and CK".

Abstract: A plurality of binary counters, each consisting of a primary and a secondary counting chain, are stepped by respective trains of clock pulses of like cadence but indeterminate phase relationship. The several primary counting chains are provided on their input sides with respective correlation circuits and on their output sides with respective sync generators, either of which is used for a concurrent restarting of both chains upon the attainment of a full count. A selection signal establishes one of the primary counting chains as the master by unblocking its sync generator while blocking its correlation circuit, the opposite being the case in all the other counters which are controlled from the unblocked sync generator through their respective correlation circuits.

Abstract: A klystron oscillator has an input cavity resonant in a TM.sub.010 mode and a larger output cavity resonant in a TM.sub.OnO mode where n is an integer greater than 1, preferably equal to 2. The input cavity, with re-entrant bosses defining a buncher gap, projects into the output cavity to form one of two re-entrant bosses thereof defining a catcher gap.

Abstract: Three or more oscillators to be locked in phase with one another are interconnected in a closed ring and have individual feedback loops including respective frequency dividers designed to keep them in step with a synchronizing frequency, equal to a fraction of their own operating frequency, fed in through an associated multiplexer. The multiplexer has a first input receiving the stepped-down feedback frequency of the immediately preceding oscillator, a second input connected to the output of the associated frequency divider, and a third input energizable with an external reference frequency such as a carrier of a PCM of FDM system. Each multiplexer, in the absence of an external switching command which holds it on its third input, stands on its first input unless a control circuit associated with the immediately preceding oscillator detects a disparity between the two frequencies fed to that preceding oscillator via the feedback loop and the multiplexer of the latter.

Abstract: A subcarrier frequency-modulated with a message signal is heterodyned with a carrier from a crystal-controlled oscillator in a mixer whose output is fed to a filter eliminating one of the resulting sidebands. In order to compensate temperature-dependent fluctuations of the carrier frequency, a function generator produces a corrective signal which is added to the message signal in the input of the frequency modulator traversed by the subcarrier. The corrective signal varies as a quadratic or a cubic function of temperature, depending upon the type of cut used on the quartz crystal controlling the carrier oscillator, with a polarity determined by which of the two sidebands is passed by the filter.

Abstract: A sampling gate of a TDM telephone system, designed to connect a subscriber station to a trunk line during an allocated time slot, comprises a pair of bucking transistors of the same conductivity type (NPN) inserted between a live wire from the station and a corresponding "hot" conductor of the trunk line whose "cold" conductor, tied to the reference wire of the subscriber line, is grounded through an elevated resistance. During the allocated time slot, the two bucking transistors are rendered conductive by a timing pulse applied across their base/emitter circuits via a transformer while a connection leading from their bases to negative biasing potential is temporarily severed by an interposed FET which is cut off by the timing pulse applied to its gate electrode via a differentiation circuit.