Abstract: In radio transmission systems having a number of radio channels available for transmission, it is necessary to recognize a transmission channel as idle. One known way of doing this is to measure the field strength on the transmission channel and carry out a threshold decision. As soon as the field strength in a transmission channel is below a preset value, this transmission channel is recognized as idle. In measuring field strength, the field strength is averaged over the entire bandwidth of the transmission channel. As a result, a transmission channel that experiences interference from the signals on its adjacent channels may not be recognized as idle, although the adjacent-channel interference has little effect on the transmission quality. The new method makes it possible to recognize the signal present in a transmission channel by means of numerous narrowband field strength measurements.

Abstract: A color television system including an encoding device in which the chrominance and high-frequency luminance are sub-sampled in time. In the decoder, the high-frequency of the color television signal of the first and second fields are added thereby eliminating cross-luminance and the demodulated, low-frequency color difference signals are added thereby eliminating cross-color.

Abstract: In recording systems in which video and audio signals are recorded in tape layers having different depths, a method and apparatus is provided which serves to ensure that the video recording bias for a video signal is always selected and adjusted for optimum results, allowance being made for an audio signal already recorded in the same tracks and for tolerances of the record carrier, the heads and the head amplifier with respect to the playback sensitivity. During recording of the video signal, the video recording bias is varied step-wise. After every change in the video recording bias, a d.c. signal is derived from the playback envelope of the audio signal, the value of the d.c. signal being a measure of the playback amplitude of the audio signal. As soon as the d.c. signal value has reached a predetermined minimum value, the video recording bias is ceased to be changed and the last value of the video recording bias is stored for the next recording process.

Abstract: A color television transmission systems including three-dimensional filtering operations at the transmitter and receiver ends with the object of obtaining a lowest possible number of interferences in the form of cross color and cross-luminance on display in which each one of the two color difference signal channels has its own three-dimensional sub-filtering operation, wherein the two sub-filters are dimensioned differently.

Abstract: In known color-under video recorders intertrack chrominance cross talk is eliminated by comb-filtering of the back-converted chrominance signal. However, if the delay circuit needed in the comb filter is a CCD delay line this will give rise to problems both in respect of production engineering and circuit design. These problems are mitigated by the novel comb filter. Comb filtering is applied to the down-converted chrominance signal. The signal path in which the signal is delayed includes a clocked CCD delay line and a phase correction circuit having a linear frequency response and whose dimensioning is such that the overall delay of the chrominance signal corresponds to the signal periodicity imposed by the signal standard and that the phase shift which occurs in the down-converted signal as a result of the recording standard in conjunction with the signal standard is eliminated.

Abstract: A method of soldering an integrated circuit with yielding connecting contacts rigidly mounted on the integrated circuits to printed circuit boards. The integrated circuit is inserted in a clamped manner into a formed opening in a printed circuit board and the connecting contacts are soldered with the conductors by means of customary soldering methods for mass production such as by wave soldering.

Abstract: A method of making of magnetic head having core halves made from ferrite with a sputtered or vaporized soft magnetic alloy of a high permeability such as sendust on the ferrite. The operating magnetic gap of the head is sefined by the soft magnetic alloy of a high permeability. The metal includes providing a longitudinal groove in a ferrite block which serves as the base material and filling this groove with a non-magnetic material such as glass. Thereafter providing vertcial grooves along the block perpendicular to the longitudinal groove. The vertical grooves are vaporized or sputtered with the soft magnetic alloy of high permeability in such a manner that they are completely filled. The block is then halved along the center of the longitudinal groove, ground so as to smooth the adjecent surfaces and provide a coil winding groove and rejoined together via a bonding or adhesive layer. It is then ground to provide the proper head shape with the individual heads then separated from the block.

Abstract: A device for use in a tape cassette recorder preventing the accidental erasing of a magnetic tape contained in a tape cassette which includes a toggle lever for scanning the recess of the cassette which is engageable with a slide of a push button activator in such a manner that the toggle lever can arrest the movement of the slide depending on whether the recess is accessible or not.

Abstract: A device for automatically adjusting a magnetic head to the position of a magnetic tape in an audio and/or video recording and/or playback apparatus having a magnetic head in contact with a portion of the magnetic tape during operation of the device, and a pivoting means supporting said head while allowing it to rotate so as to improve head-to-tape contact even when tape geometry and pressure varies.

Abstract: A circuit for generating an audible signal in a tape recorder as the tape approaches its end. The circuit includes an open loop extending between the recording amplifier and loudspeaker. The loop is closed by the metallic foil at the end of the tape when the foil bridges a pair of contacts. In the case where an exterior microphone is used with the recorder the speaker signal is electrically fed back to the amplifier.

Abstract: A headset is provided wherein each ear piece is supported to the headband by means of a support member having a wedge shaped opening therein. A wedge is positioned within the support member opening and the headband is secured to the wedge. The wedge resiliently urges a fork attached to the ear piece against the support member thereby providing a slideable, frictional engagement.

Abstract: A method and device for maintaining an exact track when playing back video ignals, which are recorded on a magnetic tape in oblique parallel tracks with different azimuth angles.

Abstract: A system for electronic editing of tape with magnetic tape recording and play-back machines for video signals.

Abstract: Method of recording and reproduction of wide frequency band video signals onto or from a magnetizable recording carrier, carried out by the following means: means for separating of the video frequency signals into first and second signals of lower and upper frequency range respectively, for converting said second signal into a third signal the frequency range of which equaling that of said first signal, for frequency modulating a carrier wave frequency by said first and third signals and for recording the frequency modulated signals by means of a twin head, for reproducing the recorded signals by means of a twin head and for amplifying, limiting and demodulating the recorded signals and reconverting the third signal into its original frequency range and combining the so reconverted third signal and said first signal.

Abstract: A tape recorder with combined on/off and sound regulating switch having means whereby when said tape recorder is turned on a variable resistor exhibits maximum resistance and thereafter returns to minimum resistance so that transient noise pulses are not recorded.

Abstract: A radio tuning arrangement is provided wherein a drive cable for rotating a uning capacitor drum in response to rotation of a tuning knob also serves to provide current to a lamp that moves with an indicator in response to rotation of the knob. The cable includes a pair of conductors that extend longitudinally off the drum to terminal posts through a clamp thereby defining a torsion section of the cable. The conductors also extend circumferentially off the drum to the indicator lamp from opposite sides of a closed path.

Abstract: An apparatus for automatically soldering components to a printed-circuit board in accordance with the "drag bath" process wherein the board is moved through a lowered section with its undersurface in contact with a solder bath and withdrawn therefrom perpendicularly by lift means.

Abstract: A control unit for a tape recorder of the cassette type is provided. The control unit includes a swing arm carrying thereon at least one idler roller to engage and drive the recorder take-up reel driver or supply reel driver. The swing arm, in turn, is frictionally connected to a fly wheel driven by the tape recorder motor so that by changing the polarity of the drive motor voltage, the appropriate mechanical interconnection may be effected through the swing arm idler to attain the desired drive function.

Abstract: A first pulse generator supplies an RC circuit including a first and second resistance and a capacitance. The voltage across the capacitance constitutes the output voltage. To decrease the time constant, a second pulse generator identical to the first is switched in between reference potential and the common point of the two resistors. The first pulse generator includes a first and second transistor connected in series between a first and second reference potential and a logic circuit which alternately drives the transistors to the conductive state thereby alternately connecting the common point of the two transistors to the first and second reference potential. The second pulse generator is identical to the first except that the logic circuit driving the two transistors also includes a state wherein both transistors are blocked causing the common point of the two transistors which is also the common point of the two resistances to be disconnected from both reference potentials.

Abstract: An apparatus for depositing flux-fluid onto conductor plates consisting of a reservoir, an overflow bath receiving flux-fluid from the reservoir, a rotating brush the bristles of which are dipped into the flux-fluid in the overflow bath as the brush is rotated and thereafter caused to impinge upon a stripping bar whereby the flux-fluid is stripped from the bristles and directed through a gap onto the conductor plates as a spray.