Abstract: In a cooling apparatus for a high-frequency receiver having an input circuit which carries signals that are not yet sufficiently amplified, the input circuit is thermally connected to a miniature cooler and is thermally insulated, including a cold output of the miniature cooler, from the environment. It is particularly favorable if the miniature cooler has no moving parts on the cooling end. The miniature receiver is preferably configured as a pulse tube cooler.

Abstract: A portion of the superconductor in a planar resonator made from that superconductor can be switched into the normally conducting state so that its effective lateral dimensions are changed. The special advantage of this planar resonator is that a switchable filter can be constructed very economically based on its planar resonator structure. Since no perturbing bodies are necessary in the field, the invention points the way to a switchable filter with reduced high frequency losses.

Abstract: The superconductor bandpass filter for electromagnetic signals includes a substrate (5); striplines (1) made of a type II superconductive material arranged on the substrate and a tuning device (2) for tuning the superconductor bandpass filter consisting of a device for changing a magnetic penetration depth .lambda.(T) of the striplines (1), so as to change the effective length, effective width and effective spacing of the striplines and thus to change the center frequency and/or the bandwidth. The device for changing the magnetic penetration depth .lambda.(T) of the striplines (1) advantageously includes a device for exerting a mechanical force or stress on the striplines and/or a device for varying a magnetic field applied to the striplines.

Abstract: The planar superconducting resonator includes a substrate (1), a symmetrically shaped stripline (2) applied to the substrate (1) in which two orthogonal electromagnetic modes are excitable and including a symmetry perturbation for coupling the two orthogonal electromagnetic modes, an additional stripline (5) arranged on the substrate in the vicinity of the symmetry perturbation, a Josephson junction (3) arranged between the symmetry perturbation and the additional stripline (5) and a device for generating and controlling a magnetic field at the Josephson junction (3) so that the degree of coupling between the two orthogonal electromagnetic modes is varied. The Josephson junction (3) is formed by a non-superconducting layer (4) arranged between the symmetry perturbation and the additional stripline (5).

Abstract: A planar filter is proposed in which a plurality of striplines arranged next to one another on a substrate are supplemented by an overcoupling stripline which couples to one another two striplines which are not immediately neighboring. The length of the overcoupling stripline is an integral multiple of a half wavelength of the center frequency of the filter.

Abstract: A chuck for a machine tool is provided and includes a chuck body that is provided with a frusto-conical opening that has guide surfaces. A clamping head is adapted to be received in the opening of the chuck body, with the clamping head having an axially extending receiving opening for workpieces, cooperating with a drawing mechanism, and being provided with gripping jaws that have mating guide surfaces. The guide surfaces of the opening of the chuck body have a pressure connection with the mating guide surfaces of the gripping jaws. The clamping head is provided with radially oriented receiving opening for the gripping jaws, which are radially movable in the receiving openings. The gripping jaws each have a width that is less than an inner radius of the opening of the chuck body.

Abstract: A collet chuck with a collet body having radially extending clamping parts with counter guiding surfaces that are cooperating with the guiding surfaces of a corresponding mandrel is provided. The guiding surfaces are formed as planar sections of the mandrel and are arranged in a common plane with the counter guiding surfaces.

Abstract: In the line-by-line recording of films (15') for producing offset printing forms or in the line-by-line exposure of offset printing plates from recording data, i.e. density values of a line, the setting values for the individual zone screws are directly calculated from the density values and are stored or, respectively, directly forwarded to the printing machine (80). Before the forwarding of the setting values to the printing machine (80), density values are advantageously converted into the setting values with masks that, with reference to printing areas, printing surface in the pages (50) and with reference to the register system of the printing machine (80) as well as with reference to the characteristic data of a page (50), contain the allocation of the setting values of the zone screws calculated from the density values of the page (50).