Abstract: When any remote unit (113-118) desires to create a talk group, it transmits an inbound message to a group call database (112). The inbound message includes the identity of the requesting communication device, and the participants of the talk group. Upon receiving the request, group the call database (112) provides an outbound message to all members of the newly created talk group giving them a chance to opt out of inclusion into the new talk group. The database (112) then creates a database entry with the new talk group and those remote units that positively responded to the outbound message.

Abstract: The subject tiltrotor aircraft has three modes of operation: airplane mode, helicopter mode, and transition mode. A tilting mast, which transitions the aircraft between airplane mode and helicopter mode, is controlled by systems that allow selective movement of the rotor blades between the flight modes. A hub couples the rotor blades to the tilting mast such that torque and thrust are transferred, while allowing rotor thrust vector tilting. A main swash plate controls rotor thrust vector direction. Pitch horns are coupled to the rotor blades and the main swash plate via pitch links such that swash plate inputs are communicated to the rotor blades. The pitch links are coupled at “delta-3” values that are not optimum. A feedback swash plate and feedback links receive disk tilting inputs from the rotor blades, and supply inputs to the main swash plate, which compensates for the less than optimum delta-3 coupling.

Abstract: An improved stepped-impedance low pass filter includes a stepped-impedance low pass filter having at least one electrically conductive transmission line, such as a parallel plate, coaxial, or two-wire transmission line, having at least one inductive element and at least one capacitive element. The capacitive elements and the inductive elements are disposed in an alternating manner along a length of the transmission line. The resonance suppressed stepped-impedance low pass filter also includes at least one electrically conductive suppression element disposed along the inductive elements of the stepped-impedance low pass filter, such as centered along the inductive elements between pairs of capacitive elements. The suppression elements suppress a spurious response at at least one resonant frequency.

Abstract: An apparatus and method for switching waveguides between T switch and a bypass waveguide. The apparatus comprises a housing having a first, second and third housing port and a waveguide rotor, having a first and second rotary position. The waveguide rotor includes a first T waveguide, having a first and second T port, for connecting the second and third housing ports in the first rotary position, a second T waveguide having a third and fourth T port, for connecting the first and fourth housing ports in the first rotary position and a bypass waveguide, having a first and second bypass port, for connecting the first and second housing ports in the second rotary position. The first and second rotary positions are alternately selectable by rotating the waveguide rotor.

Abstract: An aircraft with a tilt rotor assembly comprising a craft body, a plurality of rotor blades which are subject to three modes of flight operation, a tilting mast coupling the plurality of rotor blades to the craft body and for selectively moving the plurality of rotor blades between the three modes of flight operation, a hub coupling the plurality of rotor blades to the tilting mast in a manner which transfers torque and thrust while allowing tilting of a rotor thrust vector, a main swashplate for tilting in response to operator input to control the direction of the rotor thrust vector, a plurality of pitch horns, each mechanically coupled to a particular one of the plurality of rotor blades and to the main swashplate, for communicating swashplate input to each of the plurality of rotor blades, a plurality of links coupling the main swashplate to the plurality of pitch horns, wherein each of the plurality of pitch horns is mechanically coupled to a particular one of the plurality of rotor blades by one of the

Abstract: An apparatus and method for switching waveguides between T switch and a bypass waveguide. The apparatus comprises a housing having a first, second and third housing port and a waveguide rotor, having a first and second rotary position. The waveguide rotor includes a first T waveguide, having a first and second T port, for connecting the second and third housing ports in the first rotary position, a second T waveguide having a third and fourth T port, for connecting the first and fourth housing ports in the first rotary position and a bypass waveguide, having a first and second bypass port, for connecting the first and second housing ports in the second rotary position. The first and second rotary positions are alternately selectable by rotating the waveguide rotor.

Abstract: An apparatus and method for switching waveguides between a junction waveguide and a bypass waveguide among a plurality of housing ports. The apparatus comprises a housing having a first, second and third housing port and a waveguide rotor, having a first and second rotary position. The waveguide rotor includes a junction waveguide, having a first, second and third junction port, for combining the first, second and third housing ports in the first rotary position and a bypass waveguide, having a first and second bypass port, for connecting the first and second housing ports in the second rotary position. The junction and bypass waveguides are alternately selectable by rotating the waveguide rotor to the first and second rotary positions.

Abstract: An apparatus and method for switching waveguides between a junction waveguide and a bypass waveguide among a plurality of housing ports. The apparatus comprises a housing having a first, second and third housing port and a waveguide rotor, having a first and second rotary position. The waveguide rotor includes a junction waveguide, having a first, second and third junction port, for combining the first, second and third housing ports in the first rotary position and a bypass waveguide, having a first and second bypass port, for connecting the first and second housing ports in the second rotary position. The junction and bypass waveguides are alternately selectable by rotating the waveguide rotor to the first and second rotary positions.

Abstract: A waveguide switch matrix is disclosed. The switch matrix includes a number of input waveguides that may be selectably connected to a number of output waveguides. A switch apparatus is provided at the intersection of each input waveguide and each output waveguide. The switch apparatus includes probes inserted into both the input waveguide and the output waveguide. The probes are connected through a switch arrangement. When a particular input waveguide is to be coupled to a particular output waveguide, the switch arrangement between the probes of the waveguides is closed to provide a signal path for the electromagnetic energy.

Abstract: A coaxial "M" switch having three coaxial input connectors (A, B, C) spaced evenly from each other, and three coaxial output connectors (1, 2, 3) identically arranged. In a cylindrical barrel embodiment (10) the input and output connectors are located at opposite ends of a cylindrical configuration. In one planar embodiment (30), the input and output connectors alternate with each other and define a hexagonal configuration (40). In another planar embodiment, the input connectors (A, B, C) define an inner triangular configuration (70) that is surrounded by the output connectors (1, 2, 3) defining an outer triangular configuration. In each embodiment, reeds are actuated in predetermined configurations to define three switch positions.

Abstract: A communication system in which a multipart analog message (480) is generated by a controller (112) by including an analog part delimiter (440) between successive independent analog parts (420, 431, 432, 433). The multipart analog message (480) is positioned within a synchronous protocol, in which a digital code is included to identify the position of the multipart analog message (480). The synchronous protocol is transmitted by a radio transmitter (202) and received by a selective call receiver (122). The selective call receiver (122) digitally decodes the position of the multipart analog message (480) and begins recovery of the multipart analog message (480) at the position. The selective call receiver (122) recovers the part delimiters (440) and uses them to identify the independent analog parts (420, 431, 432, 433). One of the independent parts, which is a audible response, is selected by the user and used to generate a response.

Abstract: A bandpass filter having 4-degrees of freedom includes a plurality of resonant cavities having respective Qs where at least one of the Qs is different. A plurality of main couplings couple successive resonant cavities to establish a main signal path that provides a first degree of freedom for controlling the shape of the filter's frequency response over its passband. A plurality of bridge couplings couple pairs of the resonant cavities so that the cavities are connected in a canonical circuit topology. The bridge couplings provide second and third degrees of freedom for controlling the sharpness of the frequency response 's transition between its passband and stopband and controlling the linearity of its phase, respectively. The cavities' non-uniform Qs provide a fourth degree of freedom for controlling the amplitude of the filter's frequency response in the passband so that the amplitude is within a predetermined tolerance of a desired passband shape.

Abstract: A high performance bandpass filter is produced by adding one or more "simultaneous couplings" to a conventional resonant cavity filter. A "simultaneous coupling" is created when a filter's input or output signal, normally coupled to a filter's first or last cavity respectively, is coupled to one or more other cavities. Each simultaneous coupling causes a finite-frequency insertion loss pole to be created, which produces a quasi-elliptic frequency response on its side of the passband. These poles may be placed on the left and/or right sides of the passband, so that both symmetric and asymmetric quasi-elliptic frequency responses are realizable. A diplexer constructed from two such bandpass filters has the extremely sharp selectivity provided by two asymmetric bandpass filters, thus providing a high degree of receive/transmit isolation.

Abstract: A plural cavity structure (10), suitable for use as a microwave filter (34, 34A, 34B) , has plural cavities (24, 26, 28, 30) disposed within a cylindrical aluminum housing (12) and having a central planar transverse wall (18) including an iris (38) for coupling of electromagnetic power between two successive ones of the cavities (28, 26). The transverse walls are bowed, and peripheral regions of the walls are clamped by metallic rings (66, 68, 70, 72) differing in their coefficients of thermal expansion. Thus, the rings (68, 70) of the inboard transverse walls (16, 20) are formed of titanium having a relatively high coefficient of thermal expansion, while the rings (66, 72) of the outboard transverse walls (14, 22) are formed of INVAR having a relatively low coefficient of thermal expansion.

Abstract: Adaptive digital coding of received analog information based on signal strength can be accomplished in the following manner. Once a repeater receives analog information from a communication unit, the signal quality of the received analog information is determined. Next the signal quality of the received analog information is compared with a first signal quality value. If the signal quality of the received analog information is above the first signal quality value, the received analog information is digitally coded based on a first digital coding format. If the signal quality of the received analog information is below the first signal quality value, the received analog information is digitally coded based on a second digital coding format.

Abstract: A bi-directional snap-action register mechanism for an odometer-type mechanical register display. The mechanism includes at least one register display wheel and a bi-directional cam mounted coaxially along a common shaft with the register display wheel. The bi-directional cam engages a helical groove formed along the shaft to allow lateral displacement of the bi-directional cam in a direction parallel to a rotational axis of the shaft. A pin is biased by a spring into contact with the bi-directional cam. Rotation of the shaft causes the bi-directional cam to be moved with respect to the pin. The cam abruptly rotates through a predetermined angular distance when the point of contact of the biased pin with the cam moved from a smooth portion to a step transition portion of the cam. The abrupt rotation of the cam is communicated to the register display wheel to cause a new display position to be moved into view.

Abstract: An improved method for detecting that a facility delay has changed is provided. According to the invention, a facility having a delay that may change is coupled to a transmitter and a receiver. The transmitter is coupled to a first clock that transmits a first signal based on its current reading (the first clock signal) from time to time to the receiver via the facility. The receiver is coupled to a second clock that generates a second signal based on its current reading (the second clock signal) responsive to receiving the first clock signal. In operation, the first clock signal is fed downstream (via the facility having the delay), thereby triggering the second clock signal. The two clock signals are then detected and the difference in the two clock readings computed, thereby forming .DELTA..sub.n. The process is then repeated for successive first and second clock signals, thereby forming .DELTA..sub.n+1. The absolute value of .DELTA..sub.n -.DELTA..sub.

Abstract: A simulcast system (100) having remote sites (104) that can transmit a carrier signal (107) having a modulation signal imposed thereon, wherein both the carrier and the modulation signal are derived from the same reference. Monitoring stations (108) receive transmissions from two or more remote sites, and determine the differential, if any, between the frequencies of the recovered modulation signal. The system then acts upon this information to provide correction information to one or more of the remote sites as necessary to ensure substantial carrier frequency similarity between the remote sites.

Abstract: A flashlight holder includes a C-shaped clamp that holds a flashlight by friction. The clamp is attached by an angled arm to a tripod that supports the arm in a fixed position of choice. Magnet assemblies in the legs of the tripod are mounted so as to swivel, allowing the flashlight holder to be secured by magnetic force to a ferromagnetic surface. The flashlight holder is preferably made of low-density polypropylene, which is both inexpensive to buy and easy to mold in molds that require little or no relief. The angled arm makes it easy to set a flashlight at any orientation with respect to an iron or steel surface to provide light to work on car and truck engines and the like.

Abstract: A store and forward facility for use in a multiprocessing, multinode environment is disclosed wherein two fundamental processes (transfer and delivery) perform the bulk of the activities required in this facility. A transfer process permits the creation of a message by an originating applications process and transfers this message to a similar transfer process in each of the nodes to which the message is to be delivered. This message is then in turn transferred to a delivery process which maintains a work item for each message to be delivered to a destination applications process and causes a notification to be sent to that destination application process when an earliest delivery time specified in the message has been reached. The delivery process causes the destination applications process to be created if that process is not currently executing.