Abstract: An air interface plane (AIP) of a radio frequency (RF) aperture includes: a circuit board having a first side and a second side opposite the first side; and a matrix of tapered elements arranged on the first side of the circuit board and secured to the circuit board, the matrix of tapered elements cooperating to at least one of receive or transmit an over-the-air RF signal. Suitably, each tapered element of the matrix has: a central hub extending along a longitudinal axis from a hub base which is proximate to the first side of the circuit board to an apex of the tapered element which is distal from the first side of the first circuit board; and a plurality of arms extending from the central hub at the apex of the tapered element, each of the plurality of arms including a first portion that projects the arm radially away from the longitudinal axis and a second portion that projects the arm longitudinally toward the first side of the circuit board.

Abstract: A method for providing full duplex dispatch operation includes the step of establishing a dispatch call (102) and determining if a full duplex dispatch mode is desired (104). If full duplex dispatch operation is selected, a signal is sent to the communication system requesting that full duplex dispatch operation is requested. The communication system then provides the necessary channel resources to allow for full duplex dispatch operation (106). In another embodiment, the radio user can select full duplex dispatch mode (202) prior to call setup. A radio (310) capable of providing both half duplex and full duplex dispatch operation is also described.

Abstract: A hand-held communication device with vertically oriented antenna includes a housing with a main body and a cover hingedly attached to the main body for movement between a closed position and an open position. The main body has a control surface enclosed by the cover in the closed position and accessible for operation with the cover in the open position. An antenna is movably affixed to the cover so as to form a portion of the cover with the cover in the closed position and to extend generally vertically from the cover with the cover in the open position and the communication device housing held in an operative orientation.

Abstract: A mobile communication device capable of engaging in dispatch calling receives an initial dispatch call burst (404). The initial dispatch call burst is buffered (410) in a buffer memory (208) of the mobile communication device, and an alert (410) is given to the user of the mobile communication device. When the user accepts the dispatch call (412), the mobile communication device plays (414) the buffered initial dispatch call burst over an earpiece (214) or speaker of the mobile communication device. The mobile communication device therefore permits dispatch cal operation in mobile communication devices without a loudspeaker, as well as with those that are equipped with a loudspeaker, but operated in a quiet mode.

Abstract: A hand-held communication device with vertically oriented antenna includes a housing with a main body and a cover hingedly attached to the main body for movement between a closed position and an open position. The main body has a control surface enclosed by the cover in the closed position and accessible for operation with the cover in the open position. An antenna is movably affixed to the cover so as to form a portion of the cover with the cover in the closed position and to extend generally vertically from the cover with the cover in the open position and the communication device housing held in an operative orientation.

Abstract: A method for measuring the viscosity of liquids including homogeneously mixed suspensions at known temperatures is provided. The method concerns rapidly adjusting the temperature of the liquid, stirring the liquid by rotating a stirring arrangement within the liquid at a measured speed, and measuring the power consumed by rotating the stirring arrangement in the liquid. The invention also concerns an arrangement specifically adapted for application of the method. According to both the method and arrangement, a removable vessel for the liquid is provided.

Abstract: A power shutdown circuit includes an electronic latch circuit connected in series with a monitored power supply and comparator input and power terminals. The output terminal of the comparator is coupled to the control terminal of the latch. When a monitored signal magnitude crosses a threshold, the comparator provides a control signal which renders the latch nonconductive. A main switch device also connected to an output of the latch responds to the nonconductive state thereof to remove power from an electrical load.

Abstract: A variable rate, bi-directional slew control employing a dual-concentric potentiometer having a first shaft attached to a first spring for urging it to remain in an extreme clockwise position and a second shaft urged by a second spring to remain in an extreme counterclockwise position wherein an extension of a sleeve provides the means for manual manipulation of the first shaft in a counterclockwise direction and the second shaft in a clockwise direction. A first tap associated with the first shaft is electrically connected to a first off-zero detector which is itself connected to a pulse generator which is in turn connected to an up input of an up/down counter. A second tap associated with the second shaft is electrically connected to a second off-zero detector which is connected with a second pulse generator which is in turn connected to a down input of the up/down counter.