Abstract: Heating device with a heating element of a material with positive temperature coefficient, of which two opposite sides are contacted by planar electrodes and give off the heat produced through the electrodes and planar sheets of insulating material covering the same to two heat-absorbing surfaces of a heater. The sheets of insulating material are coated on their side facing the heating element over a large area with a solder and are soldered to the electrodes. This insures permanent good heat transfer between the electrodes and the insulating material covering them. The firmly joining together of the heating element and the sheets of insulating material to form a structural unit facilitates the assembly, i.e., the installation of the heating device.

Abstract: A hand-held calculating device for calculating Federal Income Taxes or the like includes substantially flat, elongate front and rear cover members and an insert card. Suitable structure is provided for joining the cover members with the card slidably insertable therebetween. The card bears a plurality of columns on both front and rear sides thereof, each column bearing a plurality of lines of tax figures or the like. A number of through apertures or windows are provided on both front and rear cover members for viewing selected lines and columns of figures on the insert card.

Abstract: A hand-held calculator in which respective keyboards are arranged along the front face and rear face of the calculator housing and disposed along transverse axes such that each keyboard is in immediate position for use upon rotation of a user's wrist without any repositioning of the calculator in the hand. The use of both front and rear keyboards permits additional keyboard capability without increasing calculator size and without requiring multi-function keys.

Abstract: A synthesized target system utilizes emitters in the microwave or laser frequency for generating an electromagnetic energy curtain. Detectors are operatively disposed for detecting reflections within the energy curtain caused by penetrations of the curtain by one or more projectiles. A monitor is connected to the output of the detectors, and a recorder is used for storing the data output of the monitor. The event of passage of projectiles through the energy curtain, and their location upon penetration thereof, is monitored, scored, recorded and can be printed out, in hard-copy form, in real time. Physical targets and down-range human intervention therewith are eliminated.

Abstract: In an exemplary embodiment, the measuring arrangement including the x-ray tube and radiation receiver, is capable of being locked against rotation, and the patient support is capable of being locked against longitudinal movement. The x-ray beam is selectively limited in extent by means of an adjustable diaphragm. In the case of a locked measuring arrangement and patient support and a limited x-ray beam, the measured values of the radiation receiver are detected by a computer which, from them and from information regarding the cross section of a vessel to be examined, determines the concentration and/or quantity of an x-ray contrast agent therein. The information regarding the cross section is obtained with a normal computer tomographic scanning operation.

Abstract: A variable neutron collimator comprising at least three neutron absorbing blocks spaced from the position of a source of neutrons, each block having a surface remote from said position which is curved and concentric with said position, each block also having a beam-defining face adjacent the direction of the required beam, said faces together defining a polygonal aperture divergent from said position, the thickness of the blocks immediately adjacent each beam-defining face and in the general direction of the beam being sufficient to absorb substantially all neutrons emitted by the source in that direction, and the blocks being rotatable about said position so as to vary the angle of divergence of the aperture.

Abstract: The electron exit window assembly contains a metal cover plate, a titanium insert piece and a titanium exit window. The cover plate covers the interior of the last cavity of the accelerator. It contains an insert opening into which is inserted the insert piece in a vacuum tight manner. The insert piece in turn contains a hole which is covered by the exit window. The cover plate preferably is made of stainless steel, and the insert piece is preferably brazed into the insert opening of the cover plate.

Abstract: A light transmission load control system including a light responsive load controller for controlling a load setable in two states in response to optical impulses generated by an optical impulse generator. The optical impulse generator includes a light-emitting device for emitting optical impulses in response to electrical impulses produced by an electrical impulse generator. In its simplest form, the electrical impulse generator has a single moving part for controlling and indicating the state in which the load is set.

Abstract: Two boxes are mounted in vertical alignment adjacent a cylindrical mandrel surface, one above the mandrel axis and one below. The lower box contains a light source with a rectilinear filament parallel to the mandrel axis. The upper box contains an array of photosensors equidistantly spaced in a horizontal plane in a direction toward and away from the mandrel axis. Each of the photosensors is part of a separate electronic circuit with transistors, resistors, and a light emitting diode. The light emitting diodes are arranged in a display to form a column that lights up from the bottom in accordance with the thickness of a pipe wall being formed and the position of the edge of its shadow on the array of photosensors. In an alternative embodiment, a white scale is disposed in the upper box at an angle from the direction of the light source and the position of the edge of the shadow of the pipe wall on the scale gives a visual indication of thickness of the pipe wall.

Abstract: A binary vapor cycle method of electrical power generation is disclosed wherein two refrigerant fluids can be used to operate an apparatus for the generation of mechanical power as well as electrical power generation. This method, which is essentially a dual heat pump system, offers an approach to utilizing the advantages of two different refrigerants within a single apparatus. This advantage is particularly advantageous in the ulitization of low specific energy sources, such as two water sources which exist in close proximity to each other, but at different temperatures. Thus, water, which itself is a heat pump fluid, can be used as a means of transmitting heat energy to a second heat pump fluid, or refrigerant, without incurring the disadvantages of water, or water vapors, as a means to produce power, because of its high specific volume and low saturation pressures at low temperatures.

Abstract: Apparatus for generating hydroelectric power comprising a portable collector tube assembly which can be transported to the site of a water source having a waterfall sufficient in magnitude to provide a pressure head for driving a turbine generator. The tube assembly comprises telescopically arranged inner and outer tubes, and means for rotating the tube assembly and extending the inner tube so as to place the upper, extended end thereof in a position within and below the top of the waterfall so as to take advantage of the resulting hydrodynamic and hydrostatic forces.

Abstract: In a wind turbine assembly incorporating a diffuser, the diffuser includes an articulated duct formed of a set of members, such as the sectors of a conic section, which are pivotable about axes in a plane normal to the turbine axis. To permit an enlargement or contraction of the articulated duct, the members are joined by flexible gussets or, alternatively, are configured for overlapping. Springs offset from the pivoting axes are attached to the members to provide a bistable attitude thereto. In response to high winds, the spring forces are overcome by the wind forces on the articulated duct to allow the members to pivot inwardly reducing the effective wind capture area of the diffuser. The diffuser is further fabricated with slots between sections of duct to enlarge the effective area swept by the turbine blades for increased power availability from the turbine.

Abstract: An automobile electric system including an electrically operated device such as an air conditioning device which is controlled by a control switch and light devices such as head lights which are controlled by a light switch. The control switch is provided with an illuminating lamp which is adapted to indicate the switch positions and the location of the switch. A control circuit for the illuminating lamp is provided so that the lamp illuminates the control switch when the switch is actuated, with a sufficient brightness in day time to show that the switch is actuated, but with a moderate brightness in night time wherein the light switch is actuated. Further, in night time, the control switch is illuminated with a weak light when the control switch is not actuated only to indicate the location of the control switch.

Abstract: A system for controlling electrical load shedding and restoring operations includes a microprocessor system, a power measuring circuit, and a plurality of load switching relays controlled by the microprocessor system to electrically connect controlled loads of a residence to, and electrically disconnect the controlled loads from, a power line in accordance with priorities associated with the controlled loads.

Abstract: In a solid-state imaging device, electric charges corresponding to an image are stored in potential wells formed in the semiconductor substrate of a charge transfer device by supplying driving signals of different phases to the electrodes. The phases of the driving signals are changed in order somewhat to shift the potential wells during the charge storage period.

Abstract: Solid-state relay, including a full-wave rectifier bridge having a first and a second d-c terminal, a thyristor having the anode thereof connected to the first terminal and the cathode thereof connected to the second terminal, a first transistor having a load circuit and a control terminal, the load circuit of the first transistor being connected to the gate and the cathode of the thyristor and the control terminal of the first transistor being connected to at least one resistor which is in turn connected to the first terminal, a second transistor having means for supplying a control current thereto and having a load circuit, a Zener diode, and a current amplifier having an input and two input terminals, one input terminal being connected to the Zener diode which is in turn connected to the control terminal of the first transistor and the other input terminal being connected through the load circuit of the second transistor to the gate terminal of the thyristor, the current amplifier having an output and two

Abstract: A comparison circuit suitable for utilization in a television.

Abstract: In a voltage selector circuit, a plurality of supply voltages are respectively supplied to a plurality of switching elements formed of MOS transistors. The plurality of switching elements are turned on and off according to the voltage levels of input signals supplied thereto, and a voltage waveform signal corresponding to one selected among the supply voltages is taken out from a common output terminal. The substrate electrode of a specified one of the switching elements is supplied with a corresponding supply voltage as the substrate voltage in response to a voltage change of the voltage waveform signal taken out selectively, thereby reducing power loss in the circuit.

Abstract: An electromagnetic stepping motor has a stator assembly comprising two pieces. These two pieces are assembled to each other by a protrusion of cylindrical shape of one of the pieces which engages in a recess, of corresponding shape, in an extension of the other piece. The two pieces, which are of elongated general shape, are disposed parallel to each other with said one piece constituting the core of an energizing coil of the motor. The coil can be wound directly on to the piece of the stator constituting the core of the coil.

Abstract: In a rotary electric machine including a stator core and a stator winding received in slots of the stator core, a cooling medium baffling device is provided which comprises a cooling medium baffle plate fixed to the inner peripheral edge of one end of the stator core by mounting bolts protruding axially from the end of the stator core, wherein the circumferential position of each of the mounting bolts is displaced from the circumferential position defining the boundary between the different modes of phase currents flowing through the coils constituting the stator winding, thereby effectively eliminating generation of excessive heat due to excessive eddy current losses occurring locally at the end of the stator core.

Abstract: A direct-current motor unit has a direct-current motor with a stationary armature winding and a rotatable ring-shaped multipolar permanent magnet, a plurality of conductors connecting electric supply elements to the electric motor, and a stationary plate member on which the armature winding and the connecting conductors are arranged and together formed as a common printed circuit.

Abstract: A thrust preventive device for the output shaft of an electric motor comprises an electric motor having one end face from which an output shaft is projected and a rotating force transmitting member secured outside the motor to a portion of the output shaft which is projected from the one end face of the motor. The one end face of the motor has a recess therein. The rotating force transmitting member comprises a fly-wheel and a pulley. The fly-wheel has one end face which opposes the one end face of the motor and another face which is connected to the pulley. A projection which is formed of iron is provided on the one end face of the fly-wheel and projects toward the one end face of the motor and into the recess. The projection is attracted in one direction taken along a central axis of the output shaft by the magnetic force from the permanent magnets which are located in the motor housing to rotate the output shaft.

Abstract: The bipolar permanent field interior rotor for an electric machine comprises a multi-sided shaft which can be rotated about an axis of rotation, a multitude of sheet metal disks disposed on the multi-sided shaft, and a number of permanent magnet slabs. Each disk has a central hole formed by central edges and consists of at least two segments. The number of magnet slabs is smaller than the number of shaft sides. The magnet slabs directly engage respectively the sides of the shaft. The remainder of the shaft sides are engaged by central edges of the disks. The axes of magnetization of the slabs are arranged radially with respect to the axis of rotation of the shaft.

Abstract: Damping material is disposed on the trailing distal edge of a monolithic brush to enhance the brush's vibration stability. The dampening material is preferably an elastomer such as neoprene and extends along the side of the brush which contains the trailing edge of the contact surface a distance substantially greater than the thickness of the damping material.

Abstract: The lead-in wires of a fluorescent lamp are electrically connected to the base pins by mechanical means instead of welding or soldering the members to each other in the conventional manner. This is achieved by forming the pins from solid metal or rigid heat-tempered sheet metal, trimming the lead wires to a predetermined length such that the ends thereof extend beyond the plastic insulator portion of the base when the lead wires are inserted through a pair of apertures provided in the insulator and the base is placed on the sealed end of the lamp envelope, partially inserting the metal pins in the insulator apertures, wrapping the protruding ends of the lead wires around the medial portions of the respective pins, and then force fitting the inner ends of the metal pins into the apertures so that they are firmly anchored in the plastic insulator and the wrapped-around portions of the lead wires are recessed within shallow cavities provided in the outer face of the insulator.

Abstract: Disclosed is an electron-beam cathode which emits electrons in a cone-shaped pattern whose electron density is substantially uniform throughout the cone. The cathode is comprised of a needle-shaped piece of single crystal tungsten having dopant atoms of zirconium and oxygen in the bulk thereof, and having only a single (100) surface on the needle's tip. This cathode is formed by the steps providing a needle-shaped piece of single crystal tungsten having dopant atoms of zirconium and oxygen in the bulk thereof, and having a plurality of ring-shaped (100) surfaces on the needle's tip; and subsequently transforming those surfaces into diagonally oriented planar surfaces by heating the needle in an atmosphere of oxygen to diffuse tungsten atoms from the needle's tip to its sides.

Abstract: Disclosed is an electron-beam cathode which emits electrons with a low work function over a relatively wide range of temperature and pressure. The cathode is comprised of single crystal tungsten having zirconium and oxygen dopant atoms within the bulk thereof. This cathode is formed by the steps of attaching zirconium to a portion of the surface of single crystal tungsten, and heating the tungsten with the zirconium attached thereto in an atmosphere of oxygen to diffuse the zirconium and the oxygen into the bulk of the tungsten.

Abstract: A spark chamber frame 8 is manufactured using only inorganic materials. Spark chamber frame 8 includes a plurality of beams 10, 12, 14, and 16 formed from inorganic material, such as ceramic or glass, and are connected together at ends 9 with inorganic bonding material having substantially the same thermal expansion as the beam material. A plurality of wires 18 and 20 formed from an inorganic composition are positioned between opposed beams 10 and 14 and 12 and 16 so that wires 18 and 20 are uniformly spaced and form a grid. A plurality of hold-down straps 22, 23, 24, and 25 are formed of inorganic material such as ceramic or glass having substantially the same chemical and thermal properties as the beam material. Hold-down straps 22, 23, 24, and 25 overlie wires 18 and 20 extending over beams 10, 12, 14, and 16 and are bonded thereto with inorganic bonding material.

Abstract: A luminescent screen for flat image display devices, having improved light efficiency comprises a glass screen (1) provided on its inner surface with a pattern of recesses (2) corresponding to a desired luminescent dot pattern with luminescent dot surfaces (5) positioned not only along the bottom of such recesses but also along the upwardly extending recess walls and a contrasting border layer (3) is positioned on the land areas between each recess. In producing such screens, the contrasting border layer is utilized as an etch mask for the recesses and as an application mask for the luminescent material.

Abstract: In a magnetron, a metal gasket for shielding leakage of high frequency energy generated in the magnetron is inserted in a space define by the yoke, magnetic pole piece and sealing metal member. A retainer is provided on a portion of the yoke which is in contact with the gasket, for preventing the gasket from falling off.

Abstract: Method and apparatus for starting high intensity discharge lamps utilizing a spiral line pulse generator to generate high voltage, short duration starting pulses. The spiral line pulse generator includes two conductors and two insulators, each in the form of an elongated sheet, in an alternating arrangement which is rolled together in a spiral configuration having a plurality of turns. A high voltage, short duration pulse is provided upon closure of a low inductance switch coupled between the conductors. The pulse is coupled to the discharge lamp by an elongated conductor located in close proximity to the discharge tube. The spiral line pulse generator can be included within the outer jacket of the light source.

Abstract: The ion accelerator comprises an arrangement consisting of getter pumps and gas storages. This makes for a possibility of gas pressure and gas phase composition control in the device after its being unsoldered from the vacuum installation. The device is equipped with an evaporator and an additional gas storage which permit renovating the target surface as required. Proposed herein is a method ensuring higher efficiency of the device operation.

Abstract: A coaxial flashlamp for pulsed operation at high repetition rates having an annular, light emitting discharge path between fluid cooled coaxially disposed, inner and outer optically transparent tubes. Electrodes are provided at opposite ends of the discharge paths and a gas such as Xenon is provided between the electrodes. The gas is discharged by confinement between the two tubes, forced to assume a dispersed shape which permits more efficient cooling at the discharge borders by fluid coolant inside the inner tube and around the outer tube.

Abstract: A turn-signal flasher circuit for automotive vehicles wherein a turn-signal switch controls one of two turn-signal lamp circuits, and in which a hazard warning switch controls both lamp circuits simultaneously. A pulse generator controls the frequency of the flashing light output of the lamps. A second pulse generator, having a mark-to-space ratio which is substantially less than the mark-to-space ratio of the first generator, is responsive to the hazard warning switch to control frequency of the simultaneous flashing of both lamp circuits during the hazard warning operation of the flasher circuit. Accordingly, battery drain is reduced and a longer period of hazard warning operation is attainable.

Abstract: A precision regulated power supply for charging an energy storage capacitor wherein regulation is achieved using a triac to interrupt a connection between a primary winding of a transformer and a DC power source. The circuit is useful in a power supply for a photocopier flash lamp where precision regulation of light intensity is required. A control winding is wound on the transformer closely coupled to the power secondary winding. A triac is connected across the control winding such that the winding can be short circuited when it is desired to cease charging of the storage capacitor. Short-circuiting of the control winding collapses the voltage on the transformer secondary winding thereby inhibiting the flow of current in the secondary winding. Regulating circuitry senses the voltage on the capacitor and gates the control winding triac into conduction when that voltage reaches a desired magnitude.

Abstract: A device for displaying an analog signal on a display screen which is scanned by means of a line deflection generator and a frame deflection generator. The device comprises a signal processing device for forming a processed signal by repeating the analog signal at the line deflection frequency, a reference voltage generator for generating a reference voltage which is dependent on the frame deflection voltage, and a comparator for comparing the reference voltage and the processed signal and for generating a control signal which causes a brightening of the scanned display screen when both signals are approximately equal. In order to improve the picture quality, the device comprises means for adding a varying auxiliary signal to the processed signal. The frequency of this auxiliary signal amounts to at least ten times the line deflection frequency.

Abstract: A battery state of charge indicating device intended for use in a battery powered vehicle includes a battery voltage measuring circuit which produces an output signal dependent on the voltage of a storage battery. A switch element connects the output signal to a storage capacitor when conductive. Switch element is rendered conductive from time to time by a timer circuit triggered by an input from a motor current detector circuit. The timer circuit is triggered whenever the motor current falls below a threshold value, indicating that the battery current has ceased.

Abstract: A control circuit providing pulse width modulated energization to a load from a d.c. power source has a pair of input terminals connected to the source and a pair of output terminals connected to the load. A potentiometer provides a variable magnitude control signal. A first transistor has the base terminal connected to the potentiometer. The collector terminal is connected through a first resistor to the positive voltage input terminal. The emitter terminals is connected to one of the output terminals. A second transistor has its base terminal connected intermediate the first resistor and the collector terminal of the first transistor. The emitter of the second transistor is connected to the positive voltage input terminal. The collector is connected through a second resistor to the one of the output terminals. A capacitor is connected in between the collector terminal of the second transistor and the base of the first transistor.

Abstract: This disclosure deals with a time delay cut-out circuit for the start winding of an AC electric motor. The circuit includes an electronic switch which is connected in series with the start winding and which may be selectively closed to energize the start winding. Time delay means is provided which, in response to current flow therethrough, provides a timing period. An auxiliary coil is inductively coupled to the motor windings and supplies current to operate the time delay means. The time delay means operates the electronic switch to energize the start winding during the timing period. The components of the circuit, except for the coil, are mounted in a capsule which may be plugged into the motor from the exterior of the stator. The time delay means includes a self heating, heat responsive device, and the components are sized and arranged to optimize the heat generation and dissipation properties and thereby obtain the desired operating characteristics.

Abstract: A control for a profiling machining tool, and a method for controlling such a tool. The machine tool includes a sensing head which moves along a template or pattern to produce a signal that causes motors relatively to shift a cutting tool and a workpiece so as to duplicate in the workpiece the profile of the template or pattern. Two sinusoidal signals are generated as a consequence of stylus deflection along orthogonal axes. They are combined to form a single sinusoidal signal which is then variously processed to produce an error signal which causes the motors to operate in directions which tend to reduce the error signal, and to cause the stylus automatically to move along the profile while doing so.

Abstract: A control unit for automatically controlling the angular position of a reversible, motorized device, such as an antenna rotor, in response to a signal from an external sensor, such as a potentiometer coupled to the rotating shaft of a windvane. The unit includes integrated circuits and other electronic components for monitoring the windvane signal and for activating the rotor, as necessary, to maintain its alignment with the sensed wind direction. The unit also comprises means for providing: a no-response zone of adjustable width about the momentary, average wind direction; an adjustable, time delayed response to changes in wind direction; an automatic reversal of rotation if the rotor approaches the .+-.180.degree. position while searching for the wind direction; an automatic disabling of the rotor for windspeeds less than a selectable, threshold value.

Abstract: A dual motor drive for the turntable of a numerically controlled machine tool in which separate forward and reverse drive motors geared to the turntable are used for eliminating the effect of backlash. Circuitry, including amplifiers, is interposed between a source of numerical control signal and the motors for energizing the motors alternatively in the numerically controlled mode depending upon the polarity of the control signal and at a speed which depends upon the magnitude of such signal. For operation in the lathe mode, sources of auxiliary control signal of first and second polarity are provided.

Abstract: A device for controlling movements of pickup arm in linear tracking pickup arm apparatus comprises an offset angle detecting mechanism of photo-electricity conversion type for detecting a horizontal offset of the arm and a servo mechanism for correcting the arm offset. The servo mechanism is disabled by turning-off a light-emitting element in the detecting mechanism when the pickup arm is at an uplifting position as well as at limiting end positions in a horizontal arm travel. The initiation of the servo action of the mechanism is effected gradually by gradual illumination of the light-emitting element.

Abstract: A circuit for generating temperature dependent current for compensating an electrical circuit comprises a resistor and a semiconductor junction having different temperature coefficients. A current applied to the semiconductor junction conditions it for conduction and related potentials are maintained across the resistor and the semiconductor junction. Means receiving a portion of the current in one of the resistor and semiconductor junction develops the temperature dependent current in response to the portion. The temperature dependent current is applied to the electrical circuit to effect the desired compensation. One embodiment of the present invention includes a band-gap reference potential generating circuit in which a semiconductor junction thereof receives the temperature dependent current. Other embodiments of the present invention are employed to develop currents that are dependent upon a temperature function raised to a power.

Abstract: A correction network for a bow-shaped temperature characteristic includes a resistor and a semiconductor junction having different temperature coefficients and operated with related potentials thereacross to generate temperature-dependent currents responsive to an input current. That temperature-dependent current is subtractively combined with a reference current of predetermined value so that a corrective current, the magnitude of which is usually substantially zero at a predetermined temperature and is temperature-dependent at either higher and lower temperatures, respectively, is generated. In a particular embodiment, a first such corrective current is applied to a node of an extrapolated band-gap voltage reference circuit to tend to reduce the degree to which the reference potential departs from a desired value at temperatures higher than the predetermined temperature.

Abstract: A current stabilizer has a current mirror including first and second terminals through which first and second currents flow. A transistor circuit including a transistor and a resistor is connected to the first terminal so as to cause the first current to flow therein, which first current defines the current which may flow through the second terminal. The biasing of the transistor is selected with respect to the temperature coefficients of the transistor and resistor so that the first current remains constant and temperature independent.

Abstract: A regulating transformer including a base winding and a plurality of auxiliary windings adapted to be connected in whole, or in part, to said base winding. The ends of each auxiliary winding and a point between its ends are passed through a bushing to a change-over switch arranged outside the transformer tank. The base winding of the transformer is connected to the movable contact of a first change-over switch. The movable contacts of continuous change-over switches are interconnected. The movable contact of the last change-over switch is connected to an outgoing line. Each change-over switch has a movable contact that can be selectively engaged with either of a pair of fixed contacts. One of the fixed contacts is connected to one of the ends of an auxiliary transformer winding. The other of the fixed contacts is connected to a point, or tap, between the ends of the auxiliary winding.

Abstract: An apparatus for switching DC power has linearly regulated turn-on and turn-off switching transitions. The apparatus includes a differential amplifier with negative feedback which drives the control input of a controllable pass element in response to a ramp signal applied to one input of the amplifier. Feedback from the output terminal of the pass element limits the slope of the signal at the amplifier output to provide substantially linear switching transitions.

Abstract: Apparatus, and associated methodology, for testing shielded, multipair cables to detect shield and bonding faults comprises: means (20) for inductively coupling excitation source (10) to pair grouping (16); and means (50) for capacitively coupling grouping (16) to detect excitation source (10) and the signal reflected from the faults and to provide the detected signals to detector (70), which is interposed between shield (15) and capacitive means (50). Detector (70) provides fault location capability by indicating the time difference between preselected characteristics of the source and correspondingly selected characteristics of the reflected signal.

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.