Abstract: A small-sized thin frequency sensor developed for prevention of theft of an article. The frequency sensor comprises a receiving antenna portion to receive high frequency waves, and a transmitting antenna portion which is shaped into a closed loop with a diode incorporated therein and is disposed linearly to the receiving antenna portion to form an oblong rectangular contour as a whole.

Abstract: An efficiency monitoring antenna which has a sampling pick-up loop and LED coupled to the lead-in and senses and indicates returning power flow. Tuning and impedance matching elements are also included which allow the antenna to be tuned and matched to the transmission line.

Abstract: An apparatus and method for locating the vertical axis of symmetry of a sace of horizontal circular cross-section. The apparatus has a plumb structure that establishes a vertical line of sight, and a horizontal translating structure that preselectedly locates the plumb in the two horizontal dimensions. The plumb has at least three arms whose ends are constrained to lie on a circular perimeter which, because the arms are fixed to the plumb, is horizontally disposed. The translating structure and the arms are manipulated so that the end of the arms touch the surface, constraining the line of sight to be colinear with the axis of symmetry. A laser can make the axis visible. The apparatus and method are useable to locate the focal axis and focus of a parabolic antenna.

Abstract: In a detection plate, an electronic circuit capable of being activated by a suitable interrogation field to generate a pre-determined signal is provided with pin-shaped attachment means arranged so that the unauthorized detachment of the attachment means results in the interruption of an electrical conductor forming part of said electronic circuit. In the embodiment the detection plate is an earmark for animals and the attachment means includes a pin integral with the plate. The pin has a point which can be pushed through an animal's ear and the device can then be fastened on the other side of the ear. The pin includes a conductive loop which extends into the point and is connected to the electronic circiut of the plate.

Abstract: A device for adjusting the polarization of a rotatable-feed antenna with respect to a reference plane makes use for an angular reference device located near the feed-horn aperture. The angular reference device consists of a tilting mercury switch having spaced contacts bridged by a mass of mercury and rigidly fixed to the feed horn. The adjusting device includes a connector located at the rear of the antenna in a zone which is accessible for adjustment and a multiple-conductor cable establishing an electrical connection between the contacts and the connector in order to provide an electrical link between the angular reference device and a visual display device.

Abstract: An alarm device for signaling the need to retract an exterior television antenna mounted to a recreational vehicle or motor home. The device includes a switch capable of signaling a projecting orientation of the TV antenna, as opposed to a retracted position of the antenna against the vehicle. The switch is coupled to the antenna by means of a bracket or brace which is used to control the specific orientation which triggers operation of the switch. An alarm is coupled to the switch and is responsive to the detected condition of an extended antenna to thereby generate a warning for a driver of the vehicle. The alarm is coupled in series with the switch, a power source and the ignition system of the vehicle. When the driver attempts to start the vehicle, the alarm device checks the condition of the antenna and alerts the driver if the antenna is not in the safe, retracted position.

Abstract: An anti-theft tag for use in an electronic article surveillance system has a housing, a lock for releasably attaching the housing to an article to be protected, and a marker on the housing, the marker having a resonant circuit including an inductor and a capacitor, the inductor including a solenoid type winding defining a winding opening, wherein the circuit has a Performance Factor P of at least 1.times.10.sup.6 in the equation P=QA.sup.1.5, wherein Q is equal to the circuit Q, and wherein A is equal to the area of the winding opening in square millimeters.

Abstract: An apparatus for sensing the position of a satellite receiving antenna with respect to a conventional polar mount. A linear encoding strip is fixed to the antenna, and moves rectilinearly between a radiation source and a radiation detector as the position of the antenna changes. A radiation source comprising a plurality of elements and a radiation detector also comprising a plurality of elements are positioned on opposing sides of the linear encoding strip and in registration with one another. A plurality of interstices are defined on the linear encoding strip at predetermined linear positions corresponding to desired positions of the antenna. Each interstice defines at least one aperture. The number of the apertures and the position of the apertures are used to encode each interstice with a position number.

Abstract: A test system for microwave circuits such as employed in aircraft wherein a plurality of antennas are connected to a single processor whereby the continuity of the antennas and connectors between the antennas and the processor can be determined. A test signal is applied to the various antennae of the aircraft and the return signals therefrom received by a test antenna disposed in conjunction with a low-loss coupler from outside of the aircraft. An automated test circuit provides for inputting an identifier of the antenna and circuit portion being tested, and for determining the fault location within the circuit as a function of the circuit portion under test and the distance to the fault; and for displaying the fault location within the circuit. In one embodiment, the low-loss coupler includes the use of a plurality of test antennas in combination with a divider circuit connected to the test antennas by transmission lines.

Abstract: This invention relates to an improved means of orienting parabolic dish shaped TV antennas for receiving signals from relay satellites orbiting the earth, an angle indicating means associated with antenna assembly which indicates either the angle of elevation or the complementary angle then of which is equivalent to the latitude of the antenna site plus the offset or declination angle.

Abstract: A resonant circuit-bearing tag, which is capable of causing an article protection system to give an alarm, is provided with a release liner surface. To permit removal of an article to which the tag is attached without causing an alarm, a metal foil-bearing label is adhered to the release liner surface of the tag. By virtue of the release liner on the tag, the label is susceptible of being peeled off the tag, thereby restoring the tag's ability to cause an alarm.

Abstract: A circularly polarized microwave radio antenna which is constructed so that its phase center can be very easily and very accurately positioned with respect to a marker point over which the antenna is placed is disclosed. The antenna includes a ground plane, antenna elements in a common plane parallel thereto and supported by a perpendicular center post, separate feed lines for each element and a combining network all positioned symmetrically about an axial bore in the center post so that the phase center of the antenna is on the axis of the center post at the intersection with the upper surface of the ground plane. A graduated rod may be positioned in the bore to align the antenna with the marker point.

Abstract: A device for attaching an identifying display to the antenna of a car in a parking lot has a threaded rod with a lengthwise channel that fits over the stem of the antenna, a lower nut that confines the stem in the channel, an upper threaded sleeve that fits over the enlarged tip of the antenna, and a screw that fits into the top of the sleeve. A ribbon or flag can be tied through a vertical slot in the top of the screw or a rigid display member can be threaded onto it.

Abstract: A tool for indicating the position of a receiving device mounted on a convergent reflector with respect to the focus of that reflector, the tool having a collar and clamp for attaching it to the receiving device and converging, telescoping legs extending toward the reflector to indicate the angular and/or axial displacement of the receiving device from the focus of the reflector.

Abstract: A warning and protection circuit arrangement suitable for use in conjunction with a two-way portable transceiver having a removable battery pack/antenna includes a battery enclosure containing an antenna structure. A circuit is enclosed inside the battery enclosure for providing information indicative of certain predetermined parameters of the antenna or the battery. This information may be used by the transceiver to provide the user with an alert in the event an inappropriate battery pack/antenna is being used. The information may also be used to modify the normal operation of the transceiver to avoid possible damage.

Abstract: A compact, easily manipulable measuring device is provided, particularly useful for properly positioning the feed horn of a parabolic reflector antenna, or the like, relative to the satellite reflecting dish of the antenna. When installing or maintaining an antenna, it is important for optimum signal reception to position the feed horn at or near the focal point of the satellite dish. Such feed horns typically present a central axis, which if aligned with the center point of the satellite dish approximately positions the feed horn at the focal point of the satellite dish. The device of the present invention presents a telescopic rod structure coupled to a support head. The support head presents structure for attachment to the feed horn such that the rod structure preferably lies along the feed horn central axis.

Abstract: A modular field strength measuring and indicating instrument that includes as one component a sensing module with a sensitive D'Arsonval meter movement and a receptacle for interchangeable plug-in type sensing modules for measuring an electrical condition, such as electrical power. The other component is a field strength sensing module that plugs into the receptacle and which includes a self-contained DC voltage source, a sensing antenna, a high-impedance, variable gain, linear DC amplifier operatively connected to the voltage source for amplifying the field strength voltage signal sensed by the antenna, and circuitry for transmitting the amplifier output voltage signal to the D'Arsonval meter movement for indicating the field strength detected by the instrument. The field strength sensing module may be used in the meter module interchangeable with other modules, such as modules for measuring RF power in RF transmission lines.

Abstract: Detection apparatus comprising a plurality of elongate transmitting conductors each coupled to a source of electromagnetic energy and arranged for producing an electromagnetic field along the length thereof, at least one receiving conductor arranged alongside the plurality of transmitting conductors for sensing the electromagnetic field produced thereby, and alarm indicating circuitry coupled to the at least one receiving conductor for providing an alarm indication in response to a sensed disturbance of the electromagnetic field, the source of electromagnetic energy for each transmitting conductor comprising an AC voltage source of selected amplitude and phase, the selection of amplitude and phase determining the configuration of the overall electromagnetic field produced by the transmitting conductors, there being a non-zero phase relationship between the voltage sources of at least two of the transmitting conductors.

Abstract: An alignment gage for accurately positioning the azimuth and elevation angles of a fixed receiving dish antenna. The alignment gage is mounted to the dish and includes a gravity actuated pendulum cooperating with an arcuate scale for setting the elevational angle. A magnetic compass having a graduated scale is used to set the azimuth angle of the antenna. In one embodiment, the compass surmounts the pendulum so as to remain in a horizontal position. The gage is particularly adapted for use by unskilled persons for use in installing home dish antennas.

Abstract: An antenna suitable for use in the high frequency (HF) ranges includes a resonator tunable over a predetermined frequency band. The resonator consists of an insulated wire wound over a dielectric rod. Tuning is effected by sliding a metallic sleeve disposed in frictional contact over the wire. A multiplicity of these resonator units may be mounted on a single collar at different angles. Each of the resonator units will respond to a particular frequency. The remaining devices operate as a load on the antenna assembly. The antenna assembly may also be mounted on a conventional mobile antenna by means of an adaptor unit.

Abstract: An electronic theft detection apparatus for detection of saturable magnetic targets has transmitter and receiver antennas formed of single turn loops of rigid metal pipe. The antennas are rectangular and have a width, in the direction of passage, through the interrogation zone, less than the length of a shopping cart. The transmitter antenna is in the form of a rectangular loop and the receiver antenna is of the same overall size and configuration but is bisected with a conductor to form two balanced loops. The antennas are purely inductive and a series resonant circuit is inductively coupled into the transmitter antenna and a parallel resonant circuit is inductively coupled out of the receiver antenna. Special circuits are also provided for temporarily disabling the apparatus when a related lower harmonic frequency signal decreases in amplitude.

Abstract: A conventional lamp having a tubular yoke around the bulb that supports a lamp shade is converted into a security system by a simple physical electrical and mechanical coupling of two modules, eliminating wiring and installation tools. The first module, referred to as the bulb module, is screwed into the bulb socket and contains line voltage components and supports the light bulb; the second module, the probe module, contains low voltage circuitry, an audio alarm, a pigtail power connector, a light switch, and an extendable sensor probe. Upon sensing an abnormal condition, such as smoke, the bulb flashes on and off and a warning sound is provided by the audio alarm, giving both visual and audio alarm in one self-contained unit.

Abstract: A directional detector of changes in a local electrostatic field comprising two parallel flat coils of copper wire, separated by an electrically grounded plane rectangular conductor that is coated on both sides with an insulator, and associated signal conditioning electronics has been constructed. The combination of coils and plane rectangular conductors forms two independent wideband antennas which, when placed in an unobstructed electromagnetic radiation field, have induced in them electric currents of equal peak-to-peak values. When the combination was brought near an ungrounded body, such as a person standing on an insulator to earth, a coupling of high frequency potentials of the ungrounded body and the nearest coil occurred, while the coil farthest away from the body, due to the presence of the electrically grounded plane rectangular conductor, was unaffected.

Abstract: An antenna assembly for vehicle radio transceiver which is detachably mounted on the car body of an automobile, for example. The assembly includes a rod-shaped antenna, a hollow casing which supports the lower end of the antenna, a permanent magnet for securing the casing to the car body by magnetic attraction, a vibration detector which electrically detects any vibration applied to the casing, and an alarm circuit which operates to produce an alarm in response to detection of vibration applied to the casing or the car body. The vibration detector includes a printed circuit board which is placed on the bottomplate of the casing and which is formed with a first and a second electrode each including a plurality of interdigitated fingers and connected across a d.c. power supply circuit. The vibration detector also includes a conductive spherical body which is placed on the printed circuit board in a rollable manner.

Abstract: A map plate for adjusting the angle of elevation of an antenna for use with an artificial satellite communication system is composed of a map in polar coordinates of the area of signal receiving points, a group of equi-angle elevation lines which are drawn on the map, a scale of the angle of elevation which covers the whole area of the signal receiving points, which is given on the circumference of the map, a pointer which is provided on the origin of the polar coordinates and a device connected to said pointer which interconnects the revolution of the pointer to the revolution of the antenna for adjusting the angle of elevation such that the angle of elevation of the antenna will reach a designated value by driving the antenna until the pointer reaches the designated value on the scale.

Abstract: A device facilitating the tuning of an antenna system comprising a body having an opening accommodating its mount to and operative connection with a whip, wire or rod type antenna, incorporating means which in the mount thereof inherently forms the secondary of a transformer, the primary of which is provided by the antenna or its loading coil. The secondary is electromagnetically coupled to the primary to have induced therein a R.F. voltage and a resulting current actuates a signal means connected across the secondary. The signal means signals the tuned or untuned condition of the antenna to which the body is applied in accordance with the level of the sensed current.

Abstract: A system is provided for automatically actuating an alarm whenever a would-be thief attempts to remove the antenna from a vehicle equipped with a C.B. radio or other communication system. The preferred embodiment includes a hidden switch which remains depressed by the antenna until it is partially unscrewed, at which time the switch closes the alarm circuit. For example, the horn of the vehicle may be connected to the switch and serve as the alarm.

Abstract: In a small satellite earth station a directional antenna is rocked about a single axis, corresponding to an oscillatory change in declination, but constant hour angle. The rocking is approximately sinusoidal and has a period of one sidereal day. In a preferred arrangement the antenna is mounted on a rocking axis pivot which is fixed at right angles to, and rotatable for adjustment about, a polar axis member. The polar axis member is set up parallel to the earth's axis and the pivot is rotated about the polar axis member to set the hour angle. The rocking of the antenna is achieved by a crank and tie-rod arrangement driven by a clock motor mounted on the polar axis member. The arrangement is particularly simple and will, when set up, track a synchronous satellite without needing frequent adjustment.

Abstract: An illuminated call letter display or sign is bodily mounted on the transmitting antenna of a citizens band radio. An opaque housing contains a fluorescent light tube having electrical contact with the antenna and contains substances which emit light when excited by radiation. Call letters and/or the operator's radio name are displayed on a translucent or transparent panel carried by the housing.

Abstract: A transmitter antenna attachment is provided having a pair of L-shaped brackets of insulating material for attaching a fluorescent lamp on the antenna of a transmitter which lights when the transmitter is actuated. The fluorescent lamp is mounted in hollow sockets on one extremity of the brackets, with the other extremity of the brackets having openings therein which are adapted to receive and mount the lamp on an antenna wire.

Abstract: An antenna matching network for matching a citizens band radio transceiver to a standard automotive whip or windshield antenna utilizes a matching section for matching the nominal 50 ohm output of the citizens band transceiver to the generally lower impedance of the automotive antenna. A trap tuned to the citizens band prevents the output of the citizens band transmitter from damaging the automotive broadcast receiver when transmitting. The matching section is tunable over a sufficient range to match the citizens band transceiver to most automotive antennas, and a dual sensitivity indicator is utilized to aid the operator in tuning the matching network to provide optimum matching without the use of specialized equipment.

Abstract: An antenna coupling adapter device is disclosed of a type designed to connect an antenna to the output antenna jack of portable radio transmitter-receivers such as Citizens Band units. The adapter is comprised of a first coupling mating with the antenna output jack provided on the transmitter unit, a second coupling adapted to mate with the antenna coupling and the adapter also including a switch and a dummy resistive load comprised of an indicator lamp. The antenna coupling, when installed, actuates an operating plunger to operate the switch by seating and unseating of the antenna coupling to cause the switch to electrically connect either the antenna or the indicator lamp, respectively, to the transmitter output stage via the first coupling means so as to cause the indicator lamp to be automatically switched in as a dummy resistive load.

Abstract: A pointing error compensating device for compensating the error induced in a position indicator as a result of forces acting on a structure, such as gravitational forces acting on a large antenna having a reflecting dish, that is pivotal about an elevation axis.The error compensating device comprises a torque producing device having a moment arm in the form of an eccentric mass attached to a shaft coupled to the structure, the shaft being rotatable in response to a pivotal movement of the structure. The shaft is also coupled to a drive shaft of the position indicator. The eccentric mass is attached to the transmission shaft in such a manner that it applies a torque to the latter which is proportional to the cosine of the angular orientation of the structure about the elevation axis. The transmission shaft is deflected torsionally by the eccentric mass in an amount which is designed to be approximately equal and opposite to the error which otherwise would be induced into the position indicator.

Abstract: An antenna combiner 2.sup.n antenna element system with switchable variable delay line length broadband beam and null steering through 360.degree. in azimuth.

Abstract: A telescoping antenna with an indicator on a moveable telescoping antenna section which indicates the degree of telescopic movement of the moveable telescoping antenna section which is necessary to achieve a predetermined overall extended antenna length.

Abstract: A yagi antenna having a director element, a half-wave active dipole element, and a reflector element mounted on an antenna boom. All antenna elements are rods that are telescopically adjustable in length from a collapsible position to an operating length for a predetermined frequency of operation, and removable from threaded mounting for storage. The director element and reflector element are slidably adjustable on the antenna boom for independent spacing with respect to the half-wave active dipole element. The antenna boom has two mast support holes; one for horizontal polarization and the other for vertical polarization. A ferrite core member surrounds a coaxial cable connecting the half-wave active dipole element to a coaxial connector, and provides balun action between the coaxial cable and a balanced antenna feed point.