Showing papers on "Stub (electronics) published in 1968"

Covered hopper car end construction

Abstract: IN A CENTER SILL-LESS RAILROAD HOPPER CAR, A PAIR OF OPPOSED END STRUCTURES AND A CENTRAL HOPPER PORTION HAVING OPPOSED SLOPE SHEETS, EACH END PORTION COMPRISING A STUB CENTER SILL ON WHICH IS MOUNTED A FLAT HORIZONTAL SHEAR PLATE ATTACHED TO LATERAL VERTICAL SIDE SKIRT MEANS AND A BOLSTER WEB BEAM MOUNTED ON THE SHEAR PLATE AND CONNECTING WITH THE SIDE SKIRT MEANS FOR BEAMING THE IMPACT LOADS ON THE CENTER SILL INTO THE SIDE GIRDERS OF THE CAR, THE BOLSTER WEB BEAM BEING ATTACHED WITH THE RESPECTIVE SLOPE SHEET OF THE CENTER PORTION BY GUSSET MEANS MOUNTED ON THE RESPECTIVE STUB SILL OR AN END BEAM BEING MOUNTED ON THE OUTER END OF THE SHEAR PLATE BEAM AND CONNECTING WITH THE SIDES OF THE CAR.

Gain Bandwidth Properties of a Distributed Parameter Load

Abstract: The gain bandwidth restrictions are considered for a distributed parameter load consisting of a resistor shunted by an open-circuited stub of delay length \tau . An aperiodic solution for the optimum flat gain response in the frequency domain is obtained by using a computer, solution, which solves the infinite set of simultaneous constraint equations associated with the infinite number of periodically spaced load transmission zeros. It is shown that this solution converges to the largest gain bandwidth product when only the fundamental frequency band is permitted and all higher order periodicities of the frequency response are properly suppressed by progressively shifting the center frequency of the higher order passbands, as their gains are attenuated. Furthermore, a new result for optimum flat gain periodic response is obtained. In this case, the equalizer is a cascade of commensurate lines each of length \tau /2 . This gives twice the gain of the best periodic equalizer employing lines equal to the stub length \tau . Finally, synthesis techniques for realizing the optimum periodic equalizer are discussed.

Improvements in or relating to waveguide filters

Abstract: 1,133,801. Waveguide filters. STANDARD TELEPHONES & CABLES Ltd. 11 Nov., 1966, No. 50573/66. Heading H1W. A waveguide bandpass filter comprises main resonant cavities coupled by sections which are evanescent (i.e. are dimensioned below cut-off) at the passband frequency of the filter. In the form shown, the cavities C, E, G are tuned by coarse and fine tuning screws 3, 4 and the bandwidth is adjusted by means of screws 5 which affect the cut-off frequency of coupling sections D, F, H. As an alternative to screws 5, the blocks 9 forming the coupling sections may be provided with transversely slidable sections (7, Fig. 10, not shown). The filter is terminated by inductive irises 6. The Specification contains a theoretical discussion of the behaviour of the filter and detailed information on design procedure. It is pointed out that the filter propagates freely at frequencies above the cutoff frequency of the coupling sections and that it is necessary to provide means for absorbing or reflecting parasitic signals at these frequencies. Thus, the coupling section 11, Fig. 15(b) is associated with a narrow-band rejection filter comprising three resonant stubs 13 tuned by pistons 14. This may be converted to an absorptive constant-resistance filter (Fig. 16, not shown) which uses a resonant stub and a stub containing a matched dissipative load. Another form of narrow-band absorptive filter comprises a resonant-slot hybrid junction 19, Fig. 18, coupling the evanescent section 18 to a circular waveguide 20 containing a load 21. In a modification of this arrangement, the coupling section contains a section bounded by irises resonant at the rejection frequency, this cavity being coupled by a hole coupler to an external resonant cavity containing a dissipative load. The coupling section may, in addition, be provided with a series rejection filter comprising a central transverse post 30, Fig. 23(b). This behaves as a reflector and is situated at a point beyond the absorptive filter. In another arrangement (Fig. 25, not shown), the coupling section contains a cavity resonant at the rejection frequency provided with a tuning screw and a dissipative iron-dust slug. A series rejection filter (see Fig. 23) is situated just beyond the resonant cavity. Instead of using resonant rejection filters, the evanescent coupling sections may be constructed to have the properties of low-pass filters. Thus, the coupling sections 38(a), 38(b), Fig. 31(b), incorporate corrugated low-pass filters having a cut-off frequency below the parasitic frequencies. An intermediate coupling section is provided with a dissipative stub 40.

Covered hopper car end construction

Abstract: A HOPPER RAILROAD CAR END CONSTRUCTION COMPRISING END STUB CENTER SILL SPACED AWAY FROM ABD OUTWARDLY OF THE HOPPER SLOPE SHEET, A CAR UPPER END BEAM ATTACHED TO THE SLOPE SHEET AND TO THE END OF THE ROOF, A HORIZONTAL SHEAR PLATE BEAM MOUNTED ON THE STUB STILL, A TRANSVERSELY EXTENDING UPRIGHT BOLSTER WEB BEAM MOUNTED ON THE SHEAR PLATE AND JOINING WITH THE SLOPE SHEET, AN UPRIGHT END PITCHING STRUCTURE CONNECTING THE ROOF UPPER END BEAM WITH THE OUTER END OF THE SHEAR PLATE BEAM AND THE OUTER END OF THE STUB CENTER SILL, AND AN UPRIGHT INNER BOLSTER PITCHING STRUCTURE ON THE BOLSTER WEB BEAM AND ATTACHED TO THE STUB SILL AND CONNECTING THE INNER END OF THE SHEAR PLATE BEAM AND THE UPRIGHT BOLSTER WEB PLATE BEAM WITH THE SIDES OF THE CAR.

Improvements in radio antennas

Abstract: 1,105,354. Aerials. NORTHROP CORPORATION. 2 March, 1966, No. 9215/66. Heading H4A. An aerial comprises a conductive, nearly closed, ring 36 from the extremities of which a pair of conductive legs 37, 38 extend at rightangles to its plane to a common connector, such as a ground plane 40. A matching stub 42, extending radially inwards from one extremity of the ring, is connected to the inner conductor 45 of a coaxial cable 46, the outer conductor 49 of which is connected to the ground plane 40, and a radio set 50 is connected, to the aerial through the said cable. Insulating support posts 41 may be provided for the ring 36 and a tuning or loading capacitor 43 may be connected to it at the point on its perimeter farthest from the legs 37, 38. It is stated that the combined lengths of the legs and the ring should preferably be from 0A25# to 0A5# (#= optimum wavelength), that the aerial gives vertically polarized radiation, and that it is usuable over a two-to-one frequency range. The ground plate 40 may be constituted by the top of an automobile or other vehicle. In a second embodiment, instead of the matching stub 42, there is provided a coupling collar (51), Fig. 2, located on the ring (36a) at a short distance (j) from one extremity, and the inner conductor of the coaxial cable (46a) is connected thereto. It is stated that with a cable of 50 ohms impedance, (j) is about 0A0007#. In a third embodiment, two concentric coplanar loops (36b), (36c), Fig. 3, are provided, each operating over a different frequency range. Either separate coaxial cables, or a single twocored cable (46b) may be used for feeding the loops, in association with an aerial selection switch at the radio set 50.

Electroslag ingot production

Abstract: The electroslag process of ingot production in a mould is improved by providing bottom contact to the ingot via a stub or spigot provided at its bottom end

Improvements relating to micro-wave devices

Abstract: 1,114,841. Waveguide switches; semiconductor devices. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. 17 Nov., 1964 [20 Nov., 1963], No. 45831/83. Headings H1K and H1W. A variable-impedance semi-conductor device is insulated from the wall of a waveguide or the outer conductor of a co-axial line by means of an insulant having high thermal conductivity, e.g. beryllia or alumina. The semi-conductor element shown is of flat rectangular form and comprises a series of wafers 3 each having a low conductivity region enclosed between high conductivity regions of different types. A voltage is applied to the element across the centrally located conductor 4 and the broad walls of the waveguide. Heat is conducted away from the element by means of one or more blocks 6 of beryllia which contact the face or faces of the element and the walls of the guide 2. The conductivity may be varied to provide a short or open circuit across the guide. In a modification, the element is located across the mouth of a quarter-wavelength stub which is filled with the heat-conductive insulant. An element of cylindrical form may be located between the ends of two inner conductor sections of a co-axial line. The element is surrounded by an annulus of insulant.

Improvements in or relating to box frames

Abstract: 1,098,828. Racks. HALL & GOULDING Ltd. Nov. 1, 1966 [Sept. 17, 1965], No. 39843/65. Heading A4H. A frame for supporting filing trays comprises four -rectangular sub frames 10, 12 made of steel rod, each having a kinked portion 14, 20 near its corners. The four sub frames are locked together at right angles to each other by snapping the kinked portions into engagement. Two sub frames 10 have stub legs 22 and longitudinally extending rods 16, 18 welded thereto.

A new specimen stub for stereophotography with the scanning electron microscope

Abstract: A new specimen stub for the Cambridge scanning electron microscope has been designed to allow oriented views of microfossils and to facilitate preparation of stereopairs. The design and operation of the new stub and its advantages over the normal stub are discussed.