Abstract: A breakaway utility pole structure having a tubular base (11) anchored in the ground substantially at ground level and adapted to telescopically secure the bottom end portion of a pole (9), the base (11) having a circumferential shear groove (20) adjacent to its bottom end, and the base being secured in the base by adhesive material (12) and by bolts (21) spaced above the shear groove (20), the shear groove is adapted to cause failure of the base when the pole is subjected to horizontal impact at a predetermined distance above ground level from a vehicle of predetermined weight moving horizontally at a predetermined minimum speed.

Abstract: Line scanning apparatus are especially compensated to limit beam divergence in one direction by embodying a specularly reflective developable helicoid. Beam divergence in the direction orthogonal to the aforementioned one direction is masked by a narrow slit extending longitudinally in the direction of the longitudinal center axis of the helicoid.

Abstract: An antenna (10) suitable for multiple frequency band utilization includes three impedance elements (11,12 and 13). The second impedance element (12), which may also be called a network (12), includes a coil (L.sub.2) and at least one other conductor (17) in operative association therewith. The second impedance element may be electrically connected to both a first impedance element (11), which may include a linear conductor (14) coupled to a radio, and a third impedance element (13), which may include a coil (L.sub.1). By constructing the network (12) so as to have appropriate dimensions, antenna 10 will have a plurality of natural resonant frequencies substantially within or nearby at least each higher band of frequencies of interest.

Abstract: The invention contemplates use of a single magnetic-field (flux) sensor mounted within an elongate probe housing, to continuously generate telemetered electric signals from which the instantaneous orientation of the housing is at all times known and from which changes in orientation may be tracked as a function of probe depth within the borehole in which the probe housing may be displaced. The telemetered electric signals provide accurate and current indications of (a) magnitude of the horizontal component of the earth's magnetic-field lines, (b) direction and magnitude of probe-axis tilt with respect to the gravitational vertical, and the direction of the earth's magnetic field, and (c) a probe-housing frame-angle reference; provision being made within the probe housing for performing substantially all discriminating, detecting and other problem-solving functions, whereby the telemetered signals are directly utilizable by recording and/or display equipment at surface end of the borehole site.

Abstract: Disclosed is an apparatus forming at least a portion of an antenna and the method of constructing the same. A generally cylindrical casing is formed to hold a spacer having a generally cylindrical outer surface. The spacer has a generally axial aperture extending therethrough to receive an antenna transmission line so that the line will be spaced from the outer surface of the spacer and the casing. An antenna wire is braided around the outer surface of the spacer to locate the same between the spacer and the casing.

Abstract: A phase-sensitive device for determining the direction of a primary magnetic field is disclosed which includes an electrically conductive rotor mounted for rotation about a predetermined axis. The rotor includes means for defining at least one electrical path. The device further comprises means for detecting those secondary magnetic field components induced by rotation of the rotor in the primary magnetic field which are of a frequency equal to the rotation frequency of the rotor and for providing a corresponding first electrical signal responsively to these secondary field components. Means are also provided for detecting the angular position of the rotor with respect to the rotation axis and for providing a second electrical signal corresponding to said angular position of the rotor. The relative phase shift of the first and second electrical signals can then be determined. This relative phase shift is related to the direction of the primary field.