Abstract: An automated method for forge welding tubulars including heating the tubular ends to be joined in a welding chamber while the heated tubular ends are maintained aligned and parallel relative to each other and at a small spacing, whereupon the heated tubular ends are pressed together while a reducing shield gas is injected into the chamber.

Abstract: A method for interconnecting tubulars by forge welding involves arranging the tubular ends that are to be interconnected at a distance, up to a few millimeters from each other in a shield gas chamber, into which a reducing non-explosive flushing fluid mixture (e.g. N2+H2) is injected; heating each tubular end within the space by means of at least three electrodes that are pressed at circumferentially spaced intervals against the wall of each tubular, adjacent to the tubular end such that a high frequency electrical current is transmitted in a substantially circumferential direction through the tubular segments between the electrodes; and moving the thus uniformly heated tubular ends towards each other until a forge weld is formed between the heated tubular ends.

Abstract: An automated method for forge welding tubulars including heating the tubular ends to be joined in a welding chamber while the heated tubular ends are maintained aligned and parallel relative to each other and at a small spacing, whereupon the heated tubular ends are pressed together while a reducing shield gas is injected into the chamber.

Abstract: Improved performance of a stacked array of short helical elements is achieved by using average spacing between elements which is less than one wavelength. Still better performance is obtained by using as antenna elements structures comprising combinations of Z-shaped radiators.

Abstract: A method for decreasing radiation from a guy wire located in a strong electromagnetic field is disclosed. The method comprises placing inductive impedances at regular intervals along a guy wire, each interval being less than a half wavelength long. Each inductive impedance is made greater than Z.sub.o but usually less than 5 Z.sub.o where Z.sub.o is the characteristic impedance of the span between inductances. It is shown that induced current distribution in a span between inductances has, say, a negative current in the central portion of the span and positive currents near the two ends of the span. It is this reversal of the direction of the induced current, together with low magnitude, that results in very low re-radiation. In practice the inductive impedances may be constructed by using coils in shunt with guy insulators. In some applications the inductive impedances may take a different form, for example, inductive sleeves or just coils may be used as inductances.

Abstract: A method for decreasing radiation from a guy wire located in a strong electromagnetic field is disclosed. The method comprises placing inductive impedances at regular intervals along a guy wire, each interval being less than a half wavelength long. Each inductive impedance is made greater than Z.sub.o but usually less than 5 Z.sub.o where Z.sub.o is the characteristic impedance of the span between inductances. It is shown that induced current distribution in a span between inductances has, say, a negative current in the central portion of the span and positive currents near the two ends of the span. It is this reversal of the direction of the induced current, together with low magnitude, that results in very low re-radiation. In practice the inductive impedances may be constructed by using coils in shunt with guy insulators. In some applications the inductive impedances may take a different form, for example, inductive sleeves or just coils may be used as inductances.

Abstract: An antenna comprising a metal panel on which are mounted two parallel collinear dipole arrays spaced on the order of a half-wavelength from each other. Each dipole array is of the order of 9 wavelengths long and is fed at its center. Half way between the two collinear arrays is mounted a zigzag antenna with its center located half way between the centers of the collinear arrays which may be staggered with respect to each other. The two collinear arrays are fed in the same relative phase with each other. The zigzag antenna and the dipole array may be fed from different sources operating at different frequencies or they may be fed from the same source and phased to radiate circularly polarized waves. A plurality of the panel antennas may be mounted around a metal cylinder to serve as an omnidirectional antenna. A square tower may serve as the metal cylinder. Several levels of one to four antennas may be mounted on a square tower depending on the shape of the area to be served.

Abstract: Monitor comprises approximately matched means for sampling currents in the radiating elements. The sample currents are divided into three sets of parts. One set is used for monitoring course position, another set for monitoring course width and the third set is used to monitor magnitudes of the currents in the radiating elements. The interference by the samples in the first and second sets with the monitoring of magnitudes is greatly reduced by selecting path lengths used in the course position and course width monitoring systems so that the interfering effect of the samples in the first and second sets nearly cancel each other. The magnitudes of the currents in the third set are compared with preset standards.

Abstract: A broadband localizer antenna array with an even number of elements is supplied by a backmatched power dividing network comprising two chains of directional couplers and a group of hybrids which divide the power among the elements in accordance with geometrical progessions. The center elements in the array may be spaced 0.6 wavelength apart at the average frequency. Other spacings between the elements are greater than 0.6 wavelength.

Abstract: A means for reducing ripple in omnidirectional radiation patterns produced by asymmetrically fed antennas arranged around a tower are disclosed. The means comprises antenna mounting panels spaced from the faces of the tower.

Abstract: A monitoring arrangement for use in a two frequency localizer guidance system using a single antenna array is disclosed. This monitoring arrangement is designed to provide monitoring signals equivalent to those that would be provided by monitors located at a distant point on the course and at a distant point located at a selected angle off the course. Additional monitoring for the clearance transmitter signals and means for determining the existence of major faults such as short circuits or open circuited lines or major injuries to the equipment.

Abstract: Improved performance of a stacked array of short helical elements is achieved by using average spacing between elements which is less than one wavelength. Still better performance is obtained by using as antenna elements structures comprising combinations of Z-shaped radiators.

Abstract: This invention comprises an antenna array of collinear, end-fed dipoles spaced substantially less than one-quarter wavelength from the reflector. Consecutive dipoles are energized through phasing loops with the end dipole energized by a coaxial feeder or by one of the two output ports of a balun. A radome with a helically wound resistance heating wire is used to protect the array from the elements. Means comprising the addition of small auxiliary radiators at one of the ends of each dipoles are provided to reduce radiation polarized perpendicular to the axis of the array.

Abstract: A method used to correct counterpoise distortion of horizontal patterns of antennas radiating horizontally polarized high frequency radiation is described and is applied to reduce undesirable amplitude modulation of the scanned carrier causing bearing errors in a doppler VOR System with amplitude modulated reference used in air navigation.