Abstract: The foreshortened dipoles of the antenna described in U.S. Pat. No. 3,732,572 are further substantially shortened with a new construction in which each radiating element comprises two portions. A planar rectangular body electrically connects to the feed point by a stem portion which attaches to the rectangular body at the farthest point from the feed point and is spaced slightly from the plane of the body to electrically isolate the two portions.

Abstract: Improved gain control in a photomultiplier tube having a plurality of dynode stages is achieved through manual or automatic change of the bias voltage on at least one of the several dynodes between the anode and cathode of the tube. By such means, maximum tube gain change is obtained with a minimum of bias voltage swing.

Abstract: A crossed log-periodic dipole antenna having a unique feedline/boom structure providing improved antenna performance. The antenna is assembled from a pair of orthogonally displaced log-periodic antennas each having a pair of half-dipole structures, each structure having a half-dipole assembly and a central feed boom. The half-dipole assembly comprises a single sheet of conducting material formed to provide a central boom portion and a plurality of half-dipole elements projecting radially from opposite sides of the boom. The boom portion has a reduced thickness, a shape which complements that of the outer surface of the boom, and is press-fitted against and bonded to the boom exterior to form an integrated rigid unit. This configuration minimizes the force required to connect each half-dipole assembly with the adjacent boom, decreases the offset distance between the two dipole halves of each antenna, and reduces the electrical shadowing effect of the booms on the antennas.

Abstract: A system for rapidly scanning a remote field of regard with transmitter laser beams comprises an optical system having a focal plane, a plurality of lasers capable of being sequentially fired, and a like number of optical fibers coupled at one end to the respective laser outputs. The opposite fiber ends lie in the focal plane of the optical system and are aligned in the direction of the height of the field of regard. The beams move rapidly across the width of the field of regard simultaneously with sequential operation of the lasers, thus illuminating the entire area of interest in a minimum of time.

Abstract: In a log-periodic monopole antenna array of the type described in U.S. Pat. No. 3,286,268, each antenna of the array having active elements spaced over the top surface of a ground structure and grounded parasitic elements interspersed between the active elements, the improvement of means for mechanically and electrically connecting the parasitic elements to a non-solderable ground structure comprising an elongated block compressed into a correspondingly shaped groove in the structure. Screw means threadedly engage the ground structure in a direction transversely of the top surface thereof and abut against the block. The lower strip portion of the parasitic elements is disposed in the groove between the block and a groove side wall and is compressed therebetween when the screw means is tightened into the structure and against the block.

Abstract: A two-dimensional image and energy profile of the output from a pulsed laser is analyzed on a pulse-by-pulse basis by a video graphics image processing system coupled to a minicomputer. An intensity distribution in psuedo color for the full beam is formed by the processor and displayed on a color monitor in real time. The minicomputer performs analytical measurements in two dimensions on the beam shape and size as well as on the pulse timing properties of the laser. The system serves as a real time diagnostic tool for laser development.

Abstract: The foreshortened dipoles of the antenna described in U.S. Pat. No. 3,732,572 are further substantially shortened without performance impairment with a new construction in which each radiating element comprises a planar rectangular body electrically connected to the feed line by a stem attached to the body remotely from the feed line and spaced slightly from the plane of the body.

Abstract: An electrically nonconductive utility cable guard for use in protecting electrical riser cables from vandalism and rodent damage. The cable guard is a U-shaped open-ended channel formed of a reinforced synthetic resin material having an overall thickness of from 1/4" to 5/8". Molded to the outer edge of each side portion of the channel are short mounting tabs having apertures therein for mounting the guard to an accommodating surface such as a utility pole. In one embodiment the tabs extend from the side walls at an angle of 105.degree.. The cable guard neatly mates with underground conduit extensions due to a novel footing integrally molded to one end of the channel. The footing uses a plurality of stepped lips extending axially and radially away from the channel to mate with the ends of conduit of various sizes.

Abstract: A hand-held tool having an elongated rod-like body with an arcuately-shaped head tapered to a rounded point for use in removing insulated wires from the end of a braided shielded cable. The tip is intentionally rounded to prevent puncturing the insulation or catching on the braided wires when the tip is inserted between the wire insulation and the shield. The outer 1/2 of the tapered head portion has a substantially elliptical cross section, as opposed to simply circular, to distribute the load bearing forces across a greater surface area on the wire insulation when the wire is pulled out of the shield. The other 1/2 of the tapered head portion is a transition to the cylindrical body from the curved ellipsoidal section. In a preferred embodiment, the tool is constructed of a polycarbonate plastic with a smoothed surface on the tapered head portion to facilitate the insulated wires sliding across the surface during use.

Abstract: A method of extracting a portion of one or more insulated wires from within a shielded cable with a minimum of damage to the wire insulation. A predetermined length of outer insulation covering one end of the shielded cable is removed, exposing a portion of the braided wire shield beneath which is then pushed back against the edge of remaining outer insulation causing a portion of the braided wires to distend and loosen. The loosened wires are separated to form an aperture in the shield thereby exposing a section of the insulated wires. The shielded cable is bent back at the aperture to further expose the insulated wires. Then the rounded tip of an elongated tool is inserted between the insulated wires and the shield causing the insulated wires to separate from the shield. Preferably the elongated tool has an arcuately-shaped tapered head with a substantially elliptical tip portion to distribute the load bearing forces on the insulation.

Abstract: A selected one of a plurality of unique N-bit digital code words that corresponds to an associated signaling message is continuously transmitted until it is desired to transmit a different signaling message. Decoder logic in the receiver looks at a new group of N-signaling bits during each signaling bit interval, without reference to the start of a transmitted code word, and makes a decision during each signaling bit interval as to what signaling message was transmitted. In this manner a keep-alive signal is virtually continuously provided in the receiver. Latch circuitry repeats the previous decision from the decoder logic when the current group of N-signaling bits does not correspond to one of the unique code words or an ordered permutation thereof. In an alternate embodiment a memory circuit requires that the decoder logic repeat the same decision as to what signaling message was transmitted for P consecutive groups of N-signaling bits (i.e.

Abstract: The output of a laser oscillator is doubly passed through a birefringement medium, a quarter-wave plate and a laser amplifier by reflection from a phase conjugate mirror, the birefringent medium being between the oscillator and the plate in the path of the initial and reflected oscillator output. The birefringent medium divides the oscillator output into a first set of orthogonal polarization components (rays) and refracts one of them at a first angle successively through the plate and amplifier for reflection from the mirror through the amplifier, plate and medium. The reflected ray is amplified and then divided by the medium into a second set of orthogonal ray components which exit the medium at different angles away from the oscillator. In another embodiment, a second quarter-wave plate is added between the amplifier and mirror, and in a third embodiment the amplifier is positioned between the oscillator and the birefringent medium.

Abstract: An optical scanner/pulse iniator used for deriving power consumption data from a power meter has a pair of light sources modulated by a square wave having a repetition rate R and an OFF period P. The light beams produced by the light sources are positioned to reflect off of spatially separated points on the rotor (disc) in a power meter so that as the rotor rotates a non-reflective stripe will block the light beams one after the other. A first light sensor is positioned to receive the first light beam after being reflected off the rotor and provides an output signal indicating when the first beam is OFF for a period of time that greater than P. A second light sensor is positioned to receive the second light beam after being reflected by the rotor and it also provides an output signal indicating when the second beam is OFF for a period of time greater than P.

Abstract: A selected one of a plurality of unique N-bit digital code words that corresponds to an associated signaling message is continuously transmitted until it is desired to transmit a different signaling message. Decoder logic in the receiver looks at a new group of N-signaling bits during each signaling bit interval, without reference to the start of a transmitted code word, and makes a decision during each signaling bit interval as to what signaling message was transmitted. In this manner a keep-alive signal is virtually continuously provided in the receiver. Latch circuitry repeats the previous decision from the decoder logic when the current group of N-signaling bits does not correspond to one of the unique code words or an ordered permutation thereof. In an alternate embodiment a memory circuit requires that the decoder logic repeat the same decision as to what signaling message was transmitted for P consecutive groups of N-signaling bits (i.e.

Abstract: A technique is disclosed for use in an electronic raster-scan display system, for generating characters of variable size using a stroke-vector technique. An incoming data signal defines the type of character to be displayed, the horizontal X and vertical Y character field dimensions, the character drawing point, and any character rotation or reflection. Using that part of the data signal that defines the character type as a memory address, a character microprogram is retrieved containing a stroke-vector character mask and a stroke resolution factor representing the number x of horizontal stroke-vectors in a straight line and the number y of vertical stroke-vectors in a straight line that are used by said character mask to represent said character within a normalized character field.

Abstract: A novel 3-way digital branching network located at a telecommunications repeater branches digital service channel signals into and out of the digital transmission system. On the drop side a first adder combines the West-to-East and East-to-West digital service channel signals before being converted to analog signals for use by the local service channel equipment. On the insert side the locally generated service channel signals are digitized and then digitally combined with the through path signals by a second and third adder for insertion into the West-to-East and East-to-West digital transmission paths.

Abstract: Drift of the standing wave pattern in an acoustic doppler intrusion detection system in a confined space is compensated by adjusting the relative radiating and receiving positions of the radiator and receiver transducers, respectively, either mechanically or electrically until the signal level of the carrier wave at the receiver transducer is optimized. In the mechanical adjustment mode, either the receiver transducer or the radiating transducer is supported for movement relative to the other and is moved by a motor energized under the control of a signal level sensor circuit connected to the output of the receiver transducer. In another mode, a plurality of receiver (or alternatively radiator) transducers are connected through a switch to the signal level sensor circuit which in response to a drop in received signal level below a predetermined threshold, selectively switches the active transducer to optimize the received signal level.

Abstract: A novel stroke-vector character generator is disclosed for generating characters or the like in a raster-scan video display system. An external data signal defines the type of character to be displayed, the character field dimensions, the character drawing point, and any character rotation or reflection. Using that part of the data signal that defines the character type as a memory address, the character generator retrieves from memory a character microprogram containing a plurality of encoded binary valued stroke-drawing directives. These directives are instructions to a decoder how to generate all of the shape dependent attributes for a series of chain related stroke-vectors that define the overall shape of the character to be displayed. Once defined in the system, each stroke-vector is scaled so that the character cell size matches the character field dimensions defined by the external data signal.

Abstract: A novel method is disclosed for use in an electronic raster-scan display system, for generating characters using a stroke-vector technique. An incoming data signal defines the type of character to be displayed, the character field dimensions, the character drawing point, and any character rotation or reflection. Using that part of the data signal that defines the character type as a memory address, a character microprogram is retrieved containing a plurality of encoded binary valued stroke-drawing directives. These directives are instructions detailing how to generate all of the shape dependent attributes for a series of chain related stroke-vectors that define the overall shape of a character to be displayed. The encoded drawing directives are decoded and sequentially applied to a set of initial values that define an initial virtual stroke-vector, and thereby generating all of the character-shape dependent stroke attributes to for a series of chain related stroke-vectors that define a character shape.